fixup appending keys

Signed-off-by: Vasiliy Tolstov <v.tolstov@selfip.ru>
fix lock and resize order
2017-11-28 00:34:57 +03:00 · 2017-11-22 11:51:25 +03:00 · 2017-11-02 14:49:27 +03:00 · 2016-09-27 09:09:55 +03:00 · 2016-09-27 09:05:53 +03:00 · 2015-11-19 11:22:48 +00:00
378 changed files with 39959 additions and 13894 deletions
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,12 @@
 language: go
-go: 1.2
-
-install:
- - go get code.google.com/p/go.tools/cmd/cover
+sudo: false
+matrix:
+  include:
+    - go: 1.4
+      install:
+        - go get golang.org/x/tools/cmd/cover
+        - go get golang.org/x/tools/cmd/vet
+    - go: 1.5

 script:
- - ./test
+ - ./test
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -39,22 +39,25 @@ Thanks for your contributions!

 ### Format of the Commit Message

-We follow a rough convention for commit messages borrowed from AngularJS. This
-is an example of a commit:
+We follow a rough convention for commit messages that is designed to answer two
+questions: what changed and why. The subject line should feature the what and
+the body of the commit should describe the why.

 ```
-    feat(scripts/test-cluster): add a cluster test command
+environment: write new keys in consistent order

-    this uses tmux to setup a test cluster that you can easily kill and
-    start for debugging.
+Go 1.3 randomizes the ordering of keys when iterating over a map.
+Sort the keys to make this ordering consistent.
+
+Fixes #38
 ```

 The format can be described more formally as follows:

 ```
-<type>(<scope>): <subject>
+<subsystem>: <what changed>
 <BLANK LINE>
-<body>
+<why this change was made>
 <BLANK LINE>
 <footer>
 ```
@@ -63,25 +66,3 @@ The first line is the subject and should be no longer than 70 characters, the
 second line is always blank, and other lines should be wrapped at 80 characters.
 This allows the message to be easier to read on GitHub as well as in various
 git tools.
-
-#### Subject Line
-
-The subject line contains a succinct description of the change.
-
-#### Allowed `<type>`s
- *feat* (feature)
- *fix* (bug fix)
- *docs* (documentation)
- *style* (formatting, missing semi colons, …)
- *refactor*
- *test* (when adding missing tests)
- *chore* (maintain)
-
-#### Allowed `<scope>`s
-
-Scopes can anything specifying the place of the commit change in the code base - 
-for example, "api", "store", etc.
-
-
-For more details on the commit format, see the [AngularJS commit style
-guide](https://docs.google.com/a/coreos.com/document/d/1QrDFcIiPjSLDn3EL15IJygNPiHORgU1_OOAqWjiDU5Y/edit#).
--- a/Documentation/cloud-config-deprecated.md
+++ b/Documentation/cloud-config-deprecated.md
@@ -0,0 +1,38 @@
+# Deprecated Cloud-Config Features
+
+## Retrieving SSH Authorized Keys
+
+### From a GitHub User
+
+Using the `coreos-ssh-import-github` field, we can import public SSH keys from a GitHub user to use as authorized keys to a server.
+
+```yaml
+#cloud-config
+
+users:
+  - name: elroy
+    coreos-ssh-import-github: elroy
+```
+
+### From an HTTP Endpoint
+
+We can also pull public SSH keys from any HTTP endpoint which matches [GitHub's API response format](https://developer.github.com/v3/users/keys/#list-public-keys-for-a-user).
+For example, if you have an installation of GitHub Enterprise, you can provide a complete URL with an authentication token:
+
+```yaml
+#cloud-config
+
+users:
+  - name: elroy
+    coreos-ssh-import-url: https://github-enterprise.example.com/api/v3/users/elroy/keys?access_token=<TOKEN>
+```
+
+You can also specify any URL whose response matches the JSON format for public keys:
+
+```yaml
+#cloud-config
+
+users:
+  - name: elroy
+    coreos-ssh-import-url: https://example.com/public-keys
+```
--- a/Documentation/cloud-config-locations.md
+++ b/Documentation/cloud-config-locations.md
@@ -0,0 +1,26 @@
+# Cloud-Config Locations
+
+On every boot, coreos-cloudinit looks for a config file to configure your host. Here is a list of locations which are used by the Cloud-Config utility, depending on your CoreOS platform:
+
+Location | Description
+--- | --- | ---
+|`/media/configvirtfs/openstack/latest/user_data`|`/media/configvirtfs` mount point with [config-2](/os/docs/latest/config-drive.html#contents-and-format) label. It should contain a `openstack/latest/user_data` relative path. Usually used by cloud providers or in VM installations.|
+|`/media/configdrive/openstack/latest/user_data`|FAT or ISO9660 filesystem with [config-2](/os/docs/latest/config-drive.html#qemu-virtfs) label and `/media/configdrive/` mount point. It should also contain a `openstack/latest/user_data` relative path. Usually used in installations which are configured by USB Flash sticks or CDROM media.|
+|Kernel command line: `cloud-config-url=http://example.com/user_data`.| You can find this string using this command `cat /proc/cmdline`. Usually used in [PXE](/os/docs/latest/booting-with-pxe.html) or [iPXE](/os/docs/latest/booting-with-ipxe.html) boots.|
+|`/var/lib/coreos-install/user_data`| When you install CoreOS manually using the [coreos-install](/os/docs/latest/installing-to-disk.html) tool. Usually used in bare metal installations.|
+|`/usr/share/oem/cloud-config.yml`| Path for OEM images.|
+|`/var/lib/coreos-vagrant/vagrantfile-user-data`| Vagrant OEM scripts automatically store Cloud-Config into this path. |
+|`/var/lib/waagent/CustomData`| Azure platform uses OEM path for first Cloud-Config initialization and then `/var/lib/waagent/CustomData` to apply your settings.|
+|`http://169.254.169.254/metadata/v1/user-data` `http://169.254.169.254/2009-04-04/user-data` `https://metadata.packet.net/userdata`|DigitalOcean, EC2 and Packet cloud providers correspondingly use these URLs to download Cloud-Config.|
+|`/usr/share/oem/bin/vmtoolsd --cmd "info-get guestinfo.coreos.config.data"`|Cloud-Config provided by [VMware Guestinfo][VMware Guestinfo]|
+|`/usr/share/oem/bin/vmtoolsd --cmd "info-get guestinfo.coreos.config.url"`|Cloud-Config URL provided by [VMware Guestinfo][VMware Guestinfo]|
+
+[VMware Guestinfo]: vmware-guestinfo.md
+
+You can also run the `coreos-cloudinit` tool manually and provide a path to your custom Cloud-Config file:
+
+```sh
+sudo coreos-cloudinit --from-file=/home/core/cloud-config.yaml
+```
+
+This command will apply your custom cloud-config.
--- a/Documentation/cloud-config-oem.md
+++ b/Documentation/cloud-config-oem.md
@@ -13,20 +13,20 @@ If no **id** field is provided, coreos-cloudinit will ignore this section.

 For example, the following cloud-config document...

-```
+```yaml
 #cloud-config
 coreos:
  oem:
-    id: rackspace
-    name: Rackspace Cloud Servers
-    version-id: 168.0.0
-    home-url: https://www.rackspace.com/cloud/servers/
-    bug-report-url: https://github.com/coreos/coreos-overlay
+    id: "rackspace"
+    name: "Rackspace Cloud Servers"
+    version-id: "168.0.0"
+    home-url: "https://www.rackspace.com/cloud/servers/"
+    bug-report-url: "https://github.com/coreos/coreos-overlay"
 ```

 ...would be rendered to the following `/etc/oem-release`:

-```
+```yaml
 ID=rackspace
 NAME="Rackspace Cloud Servers"
 VERSION_ID=168.0.0
--- a/Documentation/cloud-config.md
+++ b/Documentation/cloud-config.md
@@ -1,10 +1,20 @@
 # Using Cloud-Config

-CoreOS allows you to declaratively customize various OS-level items, such as network configuration, user accounts, and systemd units. This document describes the full list of items we can configure. The `coreos-cloudinit` program uses these files as it configures the OS after startup or during runtime. 
+CoreOS allows you to declaratively customize various OS-level items, such as network configuration, user accounts, and systemd units. This document describes the full list of items we can configure. The `coreos-cloudinit` program uses these files as it configures the OS after startup or during runtime.
+
+Your cloud-config is processed during each boot. Invalid cloud-config won't be processed but will be logged in the journal. You can validate your cloud-config with the [CoreOS validator]({{site.url}}/validate) or by running `coreos-cloudinit -validate`.
+
+In addition to `coreos-cloudinit -validate` command and https://coreos.com/validate/ online service you can debug `coreos-cloudinit` system output through the `journalctl` tool:
+
+```sh
+journalctl _EXE=/usr/bin/coreos-cloudinit
+```
+
+It will show `coreos-cloudinit` run output which was triggered by system boot.

 ## Configuration File

-The file used by this system initialization program is called a "cloud-config" file. It is inspired by the [cloud-init][cloud-init] project's [cloud-config][cloud-config] file. which is "the defacto multi-distribution package that handles early initialization of a cloud instance" ([cloud-init docs][cloud-init-docs]). Because the cloud-init project includes tools which aren't used by CoreOS, only the relevant subset of its configuration items will be implemented in our cloud-config file. In addition to those, we added a few CoreOS-specific items, such as etcd configuration, OEM definition, and systemd units.
+The file used by this system initialization program is called a "cloud-config" file. It is inspired by the [cloud-init][cloud-init] project's [cloud-config][cloud-config] file, which is "the defacto multi-distribution package that handles early initialization of a cloud instance" ([cloud-init docs][cloud-init-docs]). Because the cloud-init project includes tools which aren't used by CoreOS, only the relevant subset of its configuration items will be implemented in our cloud-config file. In addition to those, we added a few CoreOS-specific items, such as etcd configuration, OEM definition, and systemd units.

 We've designed our implementation to allow the same cloud-config file to work across all of our supported platforms.

@@ -16,7 +26,7 @@ We've designed our implementation to allow the same cloud-config file to work ac

 The cloud-config file uses the [YAML][yaml] file format, which uses whitespace and new-lines to delimit lists, associative arrays, and values.

-A cloud-config file should contain an associative array which has zero or more of the following keys:
+A cloud-config file must contain a header: either `#cloud-config` for processing as cloud-config (suggested) or `#!` for processing as a shell script (advanced). If cloud-config has #cloud-config header, it should followed by an associative array which has zero or more of the following keys:

 - `coreos`
 - `ssh_authorized_keys`
@@ -27,6 +37,8 @@ A cloud-config file should contain an associative array which has zero or more o

 The expected values for these keys are defined in the rest of this document.

+If cloud-config header starts on `#!` then coreos-cloudinit will recognize it as shell script which is interpreted by bash and run it as transient systemd service.
+
 [yaml]: https://en.wikipedia.org/wiki/YAML

 ### Providing Cloud-Config with Config-Drive
@@ -37,27 +49,27 @@ CoreOS tries to conform to each platform's native method to provide user data. E

 ### coreos

-#### etcd
+#### etcd (deprecated. see etcd2)

 The `coreos.etcd.*` parameters will be translated to a partial systemd unit acting as an etcd configuration file.
-We can use the templating feature of coreos-cloudinit to automate etcd configuration with the `$private_ipv4` and `$public_ipv4` fields. For example, the following cloud-config document...
+If the platform environment supports the templating feature of coreos-cloudinit it is possible to automate etcd configuration with the `$private_ipv4` and `$public_ipv4` fields. For example, the following cloud-config document...

-```
+```yaml
 #cloud-config

 coreos:
-    etcd:
-        name: node001
-	# generate a new token for each unique cluster from https://discovery.etcd.io/new
-        discovery: https://discovery.etcd.io/<token>
-	# multi-region and multi-cloud deployments need to use $public_ipv4
-        addr: $public_ipv4:4001
-        peer-addr: $private_ipv4:7001
+  etcd:
+    name: "node001"
+    # generate a new token for each unique cluster from https://discovery.etcd.io/new
+    discovery: "https://discovery.etcd.io/<token>"
+    # multi-region and multi-cloud deployments need to use $public_ipv4
+    addr: "$public_ipv4:4001"
+    peer-addr: "$private_ipv4:7001"
 ```

-...will generate a systemd unit drop-in like this:
+...will generate a systemd unit drop-in for etcd.service with the following contents:

-```
+```yaml
 [Service]
 Environment="ETCD_NAME=node001"
 Environment="ETCD_DISCOVERY=https://discovery.etcd.io/<token>"
@@ -66,34 +78,157 @@ Environment="ETCD_PEER_ADDR=192.0.2.13:7001"
 ```

 For more information about the available configuration parameters, see the [etcd documentation][etcd-config].
-Note that hyphens in the coreos.etcd.* keys are mapped to underscores.

-[etcd-config]: https://github.com/coreos/etcd/blob/master/Documentation/configuration.md
+_Note: The `$private_ipv4` and `$public_ipv4` substitution variables referenced in other documents are only supported on Amazon EC2, Google Compute Engine, OpenStack, Rackspace, DigitalOcean, and Vagrant._

-#### fleet
+[etcd-config]: https://github.com/coreos/etcd/blob/release-0.4/Documentation/configuration.md

-The `coreos.fleet.*` parameters work very similarly to `coreos.etcd.*`, and allow for the configuration of fleet through environment variables. For example, the following cloud-config document...
+#### etcd2

-```
+The `coreos.etcd2.*` parameters will be translated to a partial systemd unit acting as an etcd configuration file.
+If the platform environment supports the templating feature of coreos-cloudinit it is possible to automate etcd configuration with the `$private_ipv4` and `$public_ipv4` fields. When generating a [discovery token](https://discovery.etcd.io/new?size=3), set the `size` parameter, since etcd uses this to determine if all members have joined the cluster. After the cluster is bootstrapped, it can grow or shrink from this configured size.
+
+For example, the following cloud-config document...
+
+```yaml
 #cloud-config

 coreos:
-    fleet:
-        public-ip: $public_ipv4
-        metadata: region=us-west
+  etcd2:
+    # generate a new token for each unique cluster from https://discovery.etcd.io/new?size=3
+    discovery: "https://discovery.etcd.io/<token>"
+    # multi-region and multi-cloud deployments need to use $public_ipv4
+    advertise-client-urls: "http://$public_ipv4:2379"
+    initial-advertise-peer-urls: "http://$private_ipv4:2380"
+    # listen on both the official ports and the legacy ports
+    # legacy ports can be omitted if your application doesn't depend on them
+    listen-client-urls: "http://0.0.0.0:2379,http://0.0.0.0:4001"
+    listen-peer-urls: "http://$private_ipv4:2380,http://$private_ipv4:7001"
+```
+
+...will generate a systemd unit drop-in for etcd2.service with the following contents:
+
+```yaml
+[Service]
+Environment="ETCD_DISCOVERY=https://discovery.etcd.io/<token>"
+Environment="ETCD_ADVERTISE_CLIENT_URLS=http://203.0.113.29:2379"
+Environment="ETCD_INITIAL_ADVERTISE_PEER_URLS=http://192.0.2.13:2380"
+Environment="ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379,http://0.0.0.0:4001"
+Environment="ETCD_LISTEN_PEER_URLS=http://192.0.2.13:2380,http://192.0.2.13:7001"
+```
+
+For more information about the available configuration parameters, see the [etcd2 documentation][etcd2-config].
+
+_Note: The `$private_ipv4` and `$public_ipv4` substitution variables referenced in other documents are only supported on Amazon EC2, Google Compute Engine, OpenStack, Rackspace, DigitalOcean, and Vagrant._
+
+[etcd2-config]: https://github.com/coreos/etcd/blob/master/Documentation/configuration.md
+
+#### fleet
+
+The `coreos.fleet.*` parameters work very similarly to `coreos.etcd2.*`, and allow for the configuration of fleet through environment variables. For example, the following cloud-config document...
+
+```yaml
+#cloud-config
+
+coreos:
+  fleet:
+      public-ip: "$public_ipv4"
+      metadata: "region=us-west"
 ```

 ...will generate a systemd unit drop-in like this:

-```
+```yaml
 [Service]
 Environment="FLEET_PUBLIC_IP=203.0.113.29"
 Environment="FLEET_METADATA=region=us-west"
 ```

+List of fleet configuration parameters:
+
+- **agent_ttl**: An Agent will be considered dead if it exceeds this amount of time to communicate with the Registry
+- **engine_reconcile_interval**: Interval in seconds at which the engine should reconcile the cluster schedule in etcd
+- **etcd_cafile**: Path to CA file used for TLS communication with etcd
+- **etcd_certfile**: Provide TLS configuration when SSL certificate authentication is enabled in etcd endpoints
+- **etcd_keyfile**: Path to private key file used for TLS communication with etcd
+- **etcd_key_prefix**: etcd prefix path to be used for fleet keys
+- **etcd_request_timeout**: Amount of time in seconds to allow a single etcd request before considering it failed
+- **etcd_servers**: Comma separated list of etcd endpoints
+- **metadata**: Comma separated key/value pairs that are published with the local to the fleet registry
+- **public_ip**: IP accessible by other nodes for inter-host communication
+- **verbosity**: Enable debug logging by setting this to an integer value greater than zero
+
 For more information on fleet configuration, see the [fleet documentation][fleet-config].

-[fleet-config]: https://github.com/coreos/fleet/blob/master/Documentation/configuration.md
+[fleet-config]: https://github.com/coreos/fleet/blob/master/Documentation/deployment-and-configuration.md#configuration
+
+#### flannel
+
+The `coreos.flannel.*` parameters also work very similarly to `coreos.etcd2.*`
+and `coreos.fleet.*`. They can be used to set environment variables for
+flanneld. For example, the following cloud-config...
+
+```yaml
+#cloud-config
+
+coreos:
+  flannel:
+      etcd_prefix: "/coreos.com/network2"
+```
+
+...will generate a systemd unit drop-in like so:
+
+```
+[Service]
+Environment="FLANNELD_ETCD_PREFIX=/coreos.com/network2"
+```
+
+List of flannel configuration parameters:
+
+- **etcd_endpoints**: Comma separated list of etcd endpoints
+- **etcd_cafile**: Path to CA file used for TLS communication with etcd
+- **etcd_certfile**: Path to certificate file used for TLS communication with etcd
+- **etcd_keyfile**: Path to private key file used for TLS communication with etcd
+- **etcd_prefix**: etcd prefix path to be used for flannel keys
+- **ip_masq**: Install IP masquerade rules for traffic outside of flannel subnet
+- **subnet_file**: Path to flannel subnet file to write out
+- **interface**: Interface (name or IP) that should be used for inter-host communication
+- **public_ip**: IP accessible by other nodes for inter-host communication
+
+For more information on flannel configuration, see the [flannel documentation][flannel-readme].
+
+[flannel-readme]: https://github.com/coreos/flannel/blob/master/README.md
+
+#### locksmith
+
+The `coreos.locksmith.*` parameters can be used to set environment variables
+for locksmith. For example, the following cloud-config...
+
+```yaml
+#cloud-config
+
+coreos:
+  locksmith:
+      endpoint: "http://example.com:2379"
+```
+
+...will generate a systemd unit drop-in like so:
+
+```
+[Service]
+Environment="LOCKSMITHD_ENDPOINT=http://example.com:2379"
+```
+
+List of locksmith configuration parameters:
+
+- **endpoint**: Comma separated list of etcd endpoints
+- **etcd_cafile**: Path to CA file used for TLS communication with etcd
+- **etcd_certfile**: Path to certificate file used for TLS communication with etcd
+- **etcd_keyfile**: Path to private key file used for TLS communication with etcd
+
+For the complete list of locksmith configuration parameters, see the [locksmith documentation][locksmith-readme].
+
+[locksmith-readme]: https://github.com/coreos/locksmith/blob/master/README.md

 #### update

@@ -107,30 +242,39 @@ The `reboot-strategy` parameter also affects the behaviour of [locksmith](https:
  - _etcd-lock_: Reboot after first taking a distributed lock in etcd, this guarantees that only one host will reboot concurrently and that the cluster will remain available during the update.
  - _best-effort_ - If etcd is running, "etcd-lock", otherwise simply "reboot".
  - _off_ - Disable rebooting after updates are applied (not recommended).
- **server**: is the omaha endpoint URL which will be queried for updates.
+- **server**: The location of the [CoreUpdate][coreupdate] server which will be queried for updates. Also known as the [omaha][omaha-docs] server endpoint.
 - **group**:  signifies the channel which should be used for automatic updates.  This value defaults to the version of the image initially downloaded. (one of "master", "alpha", "beta", "stable")

+[coreupdate]: https://coreos.com/products/coreupdate
+[omaha-docs]: https://coreos.com/docs/coreupdate/custom-apps/coreupdate-protocol/
+
 *Note: cloudinit will only manipulate the locksmith unit file in the systemd runtime directory (`/run/systemd/system/locksmithd.service`). If any manual modifications are made to an overriding unit configuration file (e.g. `/etc/systemd/system/locksmithd.service`), cloudinit will no longer be able to control the locksmith service unit.*

 ##### Example

-```
+```yaml
 #cloud-config
 coreos:
  update:
-    reboot-strategy: etcd-lock
+    reboot-strategy: "etcd-lock"
 ```

 #### units

-The `coreos.units.*` parameters define a list of arbitrary systemd units to start. Each item is an object with the following fields:
+The `coreos.units.*` parameters define a list of arbitrary systemd units to start after booting. This feature is intended to help you start essential services required to mount storage and configure networking in order to join the CoreOS cluster. It is not intended to be a Chef/Puppet replacement.
+
+Each item is an object with the following fields:

 - **name**: String representing unit's name. Required.
- **runtime**: Boolean indicating whether or not to persist the unit across reboots. This is analogous to the `--runtime` argument to `systemctl enable`. Default value is false.
- **enable**: Boolean indicating whether or not to handle the [Install] section of the unit file. This is similar to running `systemctl enable <name>`. Default value is false.
+- **runtime**: Boolean indicating whether or not to persist the unit across reboots. This is analogous to the `--runtime` argument to `systemctl enable`. The default value is false.
+- **enable**: Boolean indicating whether or not to handle the [Install] section of the unit file. This is similar to running `systemctl enable <name>`. The default value is false.
 - **content**: Plaintext string representing entire unit file. If no value is provided, the unit is assumed to exist already.
- **command**: Command to execute on unit: start, stop, reload, restart, try-restart, reload-or-restart, reload-or-try-restart. Default value is restart.
- **mask**: Whether to mask the unit file by symlinking it to `/dev/null` (analogous to `systemctl mask <name>`). Note that unlike `systemctl mask`, **this will destructively remove any existing unit file** located at `/etc/systemd/system/<unit>`, to ensure that the mask succeeds. Default value is false.
+- **command**: Command to execute on unit: start, stop, reload, restart, try-restart, reload-or-restart, reload-or-try-restart. The default behavior is to not execute any commands.
+- **mask**: Whether to mask the unit file by symlinking it to `/dev/null` (analogous to `systemctl mask <name>`). Note that unlike `systemctl mask`, **this will destructively remove any existing unit file** located at `/etc/systemd/system/<unit>`, to ensure that the mask succeeds. The default value is false.
+- **drop-ins**: A list of unit drop-ins with the following fields:
+  - **name**: String representing unit's name. Required.
+  - **content**: Plaintext string representing entire file. Required.
+

 **NOTE:** The command field is ignored for all network, netdev, and link units. The systemd-networkd.service unit will be restarted in their place.

@@ -138,36 +282,51 @@ The `coreos.units.*` parameters define a list of arbitrary systemd units to star

 Write a unit to disk, automatically starting it.

-```
+```yaml
 #cloud-config

 coreos:
-    units:
-      - name: docker-redis.service
-        command: start
-        content: |
-          [Unit]
-          Description=Redis container
-          Author=Me
-          After=docker.service
+  units:
+    - name: "docker-redis.service"
+      command: "start"
+      content: |
+        [Unit]
+        Description=Redis container
+        Author=Me
+        After=docker.service

-          [Service]
-          Restart=always
-          ExecStart=/usr/bin/docker start -a redis_server
-          ExecStop=/usr/bin/docker stop -t 2 redis_server
+        [Service]
+        Restart=always
+        ExecStart=/usr/bin/docker start -a redis_server
+        ExecStop=/usr/bin/docker stop -t 2 redis_server
 ```

-Start the built-in `etcd` and `fleet` services:
+Add the DOCKER_OPTS environment variable to docker.service.

-```
+```yaml
 #cloud-config

 coreos:
-    units:
-      - name: etcd.service
-        command: start
-      - name: fleet.service
-        command: start
+  units:
+    - name: "docker.service"
+      drop-ins:
+        - name: "50-insecure-registry.conf"
+          content: |
+            [Service]
+            Environment=DOCKER_OPTS='--insecure-registry="10.0.1.0/24"'
+```
+
+Start the built-in `etcd2` and `fleet` services:
+
+```yaml
+#cloud-config
+
+coreos:
+  units:
+    - name: "etcd2.service"
+      command: "start"
+    - name: "fleet.service"
+      command: "start"
 ```

 ### ssh_authorized_keys
@@ -177,11 +336,11 @@ The `ssh_authorized_keys` parameter adds public SSH keys which will be authorize
 The keys will be named "coreos-cloudinit" by default.
 Override this by using the `--ssh-key-name` flag when calling `coreos-cloudinit`.

-```
+```yaml
 #cloud-config

 ssh_authorized_keys:
-  - ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC0g+ZTxC7weoIJLUafOgrm+h...
+  - "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC0g+ZTxC7weoIJLUafOgrm+h..."
 ```

 ### hostname
@@ -189,10 +348,10 @@ ssh_authorized_keys:
 The `hostname` parameter defines the system's hostname.
 This is the local part of a fully-qualified domain name (i.e. `foo` in `foo.example.com`).

-```
+```yaml
 #cloud-config

-hostname: coreos1
+hostname: "coreos1"
 ```

 ### users
@@ -203,16 +362,18 @@ All but the `passwd` and `ssh-authorized-keys` fields will be ignored if the use
 - **name**: Required. Login name of user
 - **gecos**: GECOS comment of user
 - **passwd**: Hash of the password to use for this user
- **homedir**: User's home directory. Defaults to /home/<name>
+- **homedir**: User's home directory. Defaults to /home/\<name\>
 - **no-create-home**: Boolean. Skip home directory creation.
 - **primary-group**: Default group for the user. Defaults to a new group created named after the user.
 - **groups**: Add user to these additional groups
 - **no-user-group**: Boolean. Skip default group creation.
 - **ssh-authorized-keys**: List of public SSH keys to authorize for this user
- **coreos-ssh-import-github**: Authorize SSH keys from Github user
- **coreos-ssh-import-url**: Authorize SSH keys imported from a url endpoint.
+- **coreos-ssh-import-github** [DEPRECATED]: Authorize SSH keys from GitHub user
+- **coreos-ssh-import-github-users** [DEPRECATED]: Authorize SSH keys from a list of GitHub users
+- **coreos-ssh-import-url** [DEPRECATED]: Authorize SSH keys imported from a url endpoint.
 - **system**: Create the user as a system user. No home directory will be created.
 - **no-log-init**: Boolean. Skip initialization of lastlog and faillog databases.
+- **shell**: User's login shell.

 The following fields are not yet implemented:

@@ -222,17 +383,17 @@ The following fields are not yet implemented:
 - **selinux-user**: Corresponding SELinux user
 - **ssh-import-id**: Import SSH keys by ID from Launchpad.

-```
+```yaml
 #cloud-config

 users:
-  - name: elroy
-    passwd: $6$5s2u6/jR$un0AvWnqilcgaNB3Mkxd5yYv6mTlWfOoCYHZmfi3LDKVltj.E8XNKEcwWm...
+  - name: "elroy"
+    passwd: "$6$5s2u6/jR$un0AvWnqilcgaNB3Mkxd5yYv6mTlWfOoCYHZmfi3LDKVltj.E8XNKEcwWm..."
    groups:
-      - sudo
-      - docker
+      - "sudo"
+      - "docker"
    ssh-authorized-keys:
-      - ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC0g+ZTxC7weoIJLUafOgrm+h...
+      - "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC0g+ZTxC7weoIJLUafOgrm+h..."
 ```

 #### Generating a password hash
@@ -255,63 +416,52 @@ perl -e 'print crypt("password","\$6\$SALT\$") . "\n"'

 Using a higher number of rounds will help create more secure passwords, but given enough time, password hashes can be reversed.  On most RPM based distributions there is a tool called mkpasswd available in the `expect` package, but this does not handle "rounds" nor advanced hashing algorithms. 

-#### Retrieving SSH Authorized Keys
-
-##### From a GitHub User
-
-Using the `coreos-ssh-import-github` field, we can import public SSH keys from a GitHub user to use as authorized keys to a server.
-
-```
-#cloud-config
-
-users:
-  - name: elroy
-    coreos-ssh-import-github: elroy
-```
-
-##### From an HTTP Endpoint
-
-We can also pull public SSH keys from any HTTP endpoint which matches [GitHub's API response format](https://developer.github.com/v3/users/keys/#list-public-keys-for-a-user).
-For example, if you have an installation of GitHub Enterprise, you can provide a complete URL with an authentication token:
-
-```
-#cloud-config
-
-users:
-  - name: elroy
-    coreos-ssh-import-url: https://github-enterprise.example.com/api/v3/users/elroy/keys?access_token=<TOKEN>
-```
-
-You can also specify any URL whose response matches the JSON format for public keys:
-
-```
-#cloud-config
-
-users:
-  - name: elroy
-    coreos-ssh-import-url: https://example.com/public-keys
-```
-
 ### write_files

-The `write-file` parameter defines a list of files to create on the local filesystem. Each file is represented as an associative array which has the following keys:
+The `write_files` directive defines a set of files to create on the local filesystem.
+Each item in the list may have the following keys:

 - **path**: Absolute location on disk where contents should be written
 - **content**: Data to write at the provided `path`
- **permissions**: String representing file permissions in octal notation (i.e. '0644')
+- **permissions**: Integer representing file permissions, typically in octal notation (i.e. 0644)
 - **owner**: User and group that should own the file written to disk. This is equivalent to the `<user>:<group>` argument to `chown <user>:<group> <path>`.
+- **encoding**: Optional. The encoding of the data in content. If not specified this defaults to the yaml document encoding (usually utf-8). Supported encoding types are:
+    - **b64, base64**: Base64 encoded content
+    - **gz, gzip**: gzip encoded content, for use with the !!binary tag
+    - **gz+b64, gz+base64, gzip+b64, gzip+base64**: Base64 encoded gzip content

-Explicitly not implemented is the **encoding** attribute.
-The **content** field must represent exactly what should be written to disk.

-```
+```yaml
 #cloud-config
 write_files:
-  - path: /etc/fleet/fleet.conf
-    permissions: 0644
+  - path: "/etc/resolv.conf"
+    permissions: "0644"
+    owner: "root"
    content: |
-      verbosity=1
-      metadata="region=us-west,type=ssd"
+      nameserver 8.8.8.8
+  - path: "/etc/motd"
+    permissions: "0644"
+    owner: "root"
+    content: |
+      Good news, everyone!
+  - path: "/tmp/like_this"
+    permissions: "0644"
+    owner: "root"
+    encoding: "gzip"
+    content: !!binary |
+      H4sIAKgdh1QAAwtITM5WyK1USMqvUCjPLMlQSMssS1VIya9KzVPIySwszS9SyCpNLwYARQFQ5CcAAAA=
+  - path: "/tmp/or_like_this"
+    permissions: "0644"
+    owner: "root"
+    encoding: "gzip+base64"
+    content: |
+      H4sIAKgdh1QAAwtITM5WyK1USMqvUCjPLMlQSMssS1VIya9KzVPIySwszS9SyCpNLwYARQFQ5CcAAAA=
+  - path: "/tmp/todolist"
+    permissions: "0644"
+    owner: "root"
+    encoding: "base64"
+    content: |
+      UGFjayBteSBib3ggd2l0aCBmaXZlIGRvemVuIGxpcXVvciBqdWdz
 ```

 ### manage_etc_hosts
@@ -321,8 +471,8 @@ Currently, the only supported value is "localhost" which will cause your system'
 to resolve to "127.0.0.1".  This is helpful when the host does not have DNS
 infrastructure in place to resolve its own hostname, for example, when using Vagrant.

-```
+```yaml
 #cloud-config

-manage_etc_hosts: localhost
+manage_etc_hosts: "localhost"
 ```
--- a/Documentation/config-drive.md
+++ b/Documentation/config-drive.md
@@ -4,7 +4,7 @@ CoreOS supports providing configuration data via [config drive][config-drive]
 disk images. Currently only providing a single script or cloud config file is
 supported.

-[config-drive]: http://docs.openstack.org/user-guide/content/enable_config_drive.html#config_drive_contents
+[config-drive]: http://docs.openstack.org/user-guide/cli_config_drive.html

 ## Contents and Format

@@ -14,17 +14,27 @@ The image should be a single FAT or ISO9660 file system with the label

 For example, to wrap up a config named `user_data` in a config drive image:

-    mkdir -p /tmp/new-drive/openstack/latest
-    cp user_data /tmp/new-drive/openstack/latest/user_data
-    mkisofs -R -V config-2 -o configdrive.iso /tmp/new-drive
-    rm -r /tmp/new-drive
+```sh
+mkdir -p /tmp/new-drive/openstack/latest
+cp user_data /tmp/new-drive/openstack/latest/user_data
+mkisofs -R -V config-2 -o configdrive.iso /tmp/new-drive
+rm -r /tmp/new-drive
+```
+
+If on OS X, replace the `mkisofs` invocation with:
+
+```sh
+hdiutil makehybrid -iso -joliet -default-volume-name config-2 -o configdrive.iso /tmp/new-drive
+```

 ## QEMU virtfs

 One exception to the above, when using QEMU it is possible to skip creating an
 image and use a plain directory containing the same contents:

-    qemu-system-x86_64 \
-        -fsdev local,id=conf,security_model=none,readonly,path=/tmp/new-drive \
-        -device virtio-9p-pci,fsdev=conf,mount_tag=config-2 \
-        [usual qemu options here...]
+```sh
+qemu-system-x86_64 \
+    -fsdev local,id=conf,security_model=none,readonly,path=/tmp/new-drive \
+    -device virtio-9p-pci,fsdev=conf,mount_tag=config-2 \
+    [usual qemu options here...]
+```
--- a/Documentation/debian-interfaces.md
+++ b/Documentation/debian-interfaces.md
@@ -0,0 +1,27 @@
+#Debian Interfaces#
+**WARNING**: This option is EXPERIMENTAL and may change or be removed at any
+point.  
+There is basic support for converting from a Debian network configuration to
+networkd unit files. The -convert-netconf=debian option is used to activate
+this feature.
+
+#convert-netconf#
+Default: ""  
+Read the network config provided in cloud-drive and translate it from the
+specified format into networkd unit files (requires the -from-configdrive
+flag). Currently only supports "debian" which provides support for a small
+subset of the [Debian network configuration]
+(https://wiki.debian.org/NetworkConfiguration). These options include:
+
+- interface config methods
+	- static
+		- address/netmask
+		- gateway
+		- hwaddress
+		- dns-nameservers
+	- dhcp
+		- hwaddress
+	- manual
+	- loopback
+- vlan_raw_device
+- bond-slaves
--- a/Documentation/vmware-guestinfo.md
+++ b/Documentation/vmware-guestinfo.md
@@ -0,0 +1,35 @@
+# VMWare Guestinfo Interface
+
+## Cloud-Config VMWare Guestinfo Variables
+
+coreos-cloudinit accepts configuration from the VMware RPC API's *guestinfo*
+facility. This datasource can be enabled with the `--from-vmware-guestinfo`
+flag to coreos-cloudinit.
+
+The following guestinfo variables are recognized and processed by cloudinit
+when passed from the hypervisor to the virtual machine at boot time. Note that
+property names are prefixed with `guestinfo.` in the VMX, e.g., `guestinfo.hostname`.
+
+|            guestinfo variable             |              type               |
+|:--------------------------------------|:--------------------------------|
+| `hostname`                            | `hostname`                      |
+| `interface.<n>.name`                  | `string`                        |
+| `interface.<n>.mac`                   | `MAC address`                   |
+| `interface.<n>.dhcp`                  | `{"yes", "no"}`                 |
+| `interface.<n>.role`                  | `{"public", "private"}`         |
+| `interface.<n>.ip.<m>.address`        | `CIDR IP address`               |
+| `interface.<n>.route.<l>.gateway`     | `IP address`                    |
+| `interface.<n>.route.<l>.destination` | `CIDR IP address`               |
+| `dns.server.<x>`                      | `IP address`                    |
+| `coreos.config.data`                  | `string`                        |
+| `coreos.config.data.encoding`         | `{"", "base64", "gzip+base64"}` |
+| `coreos.config.url`                   | `URL`                           |
+
+Note: "n", "m", "l", and "x" are 0-indexed, incrementing integers. The
+identifier for an `interface` does not correspond to anything outside of this
+configuration; it serves only to distinguish between multiple `interface`s.
+
+The guide to [booting on VMWare][bootvmware] is the starting point for more
+information about configuring and running CoreOS on VMWare.
+
+[bootvmware]: https://github.com/coreos/docs/blob/master/os/booting-on-vmware.md
--- a/3
+++ b/3
@@ -0,0 +1,3 @@
+Alex Crawford <alex.crawford@coreos.com> (@crawford)
+Jonathan Boulle <jonathan.boulle@coreos.com> (@jonboulle)
+Brian Waldon <brian.waldon@coreos.com> (@bcwaldon)
--- a/README.md
+++ b/README.md
@@ -76,4 +76,11 @@ coreos:
    etcd:
        addr: 203.0.113.29:4001
        peer-addr: 192.0.2.13:7001
-```
+```
+
+## Bugs
+
+Please use the [CoreOS issue tracker][bugs] to report all bugs, issues, and feature requests.
+
+[bugs]: https://github.com/coreos/bugs/issues/new?labels=component/cloud-init
+
--- a/35
+++ b/35
@@ -1,14 +1,37 @@
-#!/bin/bash -e
+#!/bin/bash -x

 ORG_PATH="github.com/coreos"
 REPO_PATH="${ORG_PATH}/coreos-cloudinit"
+VERSION=$(git describe --tags)
+GLDFLAGS="-X main.version=${VERSION}"

-if [ ! -h gopath/src/${REPO_PATH} ]; then
-	mkdir -p gopath/src/${ORG_PATH}
-	ln -s ../../../.. gopath/src/${REPO_PATH} || exit 255
-fi
+rm -rf bin tmp

+export GO15VENDOREXPERIMENT=1
 export GOBIN=${PWD}/bin
 export GOPATH=${PWD}/gopath
+mkdir -p $GOBIN
+mkdir -p $GOPATH
+mkdir -p bin tmp

-go build -o bin/coreos-cloudinit ${REPO_PATH}
+which go 2>/dev/null
+
+if [ "x$?" != "x0" ]; then
+    export GOROOT=$(pwd)/goroot
+    export PATH=$GOROOT/bin:$PATH
+    mkdir -p $GOROOT
+    wget https://storage.googleapis.com/golang/go1.5.linux-amd64.tar.gz -O tmp/go.tar.gz
+    tar --strip-components=1 -C $GOROOT -xf tmp/go.tar.gz
+fi
+
+if [ ! -h $GOPATH/src/${REPO_PATH} ]; then
+        mkdir -p $GOPATH/src/${ORG_PATH}
+        ln -s ../../../.. $GOPATH/src/${REPO_PATH} || echo "exit 255"
+fi
+
+set -e
+
+for os in linux freebsd netbsd openbsd windows; do
+    GOOS=${os} go build -x -ldflags "${GLDFLAGS}" -tags netgo -o bin/cloudinit-${os}-x86_64 ${REPO_PATH}
+    GOOS=${os} GOARCH=386 go build -x -ldflags "${GLDFLAGS}" -tags netgo -o bin/cloudinit-${os}-x86_32 ${REPO_PATH}
+done
--- a/config/config.go
+++ b/config/config.go
@@ -0,0 +1,164 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"fmt"
+	"reflect"
+	"regexp"
+	"strings"
+	"unicode"
+
+	yaml "gopkg.in/yaml.v2"
+)
+
+// CloudConfig encapsulates the entire cloud-config configuration file and maps
+// directly to YAML. Fields that cannot be set in the cloud-config (fields
+// used for internal use) have the YAML tag '-' so that they aren't marshalled.
+type CloudConfig struct {
+	SSHAuthorizedKeys []string   `yaml:"ssh_authorized_keys"`
+	SSHFingerprints   bool       `yaml:"no_ssh_fingerprints"`
+	Debug             bool       `yaml:"debug"`
+	RunCMD            []string   `yaml:"runcmd"`
+	NetworkConfigPath string     `yaml:"-"`
+	NetworkConfig     string     `yaml:"-"`
+	Bootstrap         string     `yaml:"-"`
+	SystemInfo        SystemInfo `yaml:"system_info"`
+	DisableRoot       bool       `yaml:"disable_root"`
+	SSHPasswdAuth     bool       `yaml:"ssh_pwauth"`
+	ResizeRootfs      bool       `yaml:"resize_rootfs"`
+	CoreOS            CoreOS     `yaml:"coreos"`
+	WriteFiles        []File     `yaml:"write_files"`
+	Hostname          string     `yaml:"hostname"`
+	Users             []User     `yaml:"users"`
+	ManageEtcHosts    EtcHosts   `yaml:"manage_etc_hosts"`
+}
+
+type CoreOS struct {
+	Etcd      Etcd      `yaml:"etcd"`
+	Etcd2     Etcd2     `yaml:"etcd2"`
+	Flannel   Flannel   `yaml:"flannel"`
+	Fleet     Fleet     `yaml:"fleet"`
+	Locksmith Locksmith `yaml:"locksmith"`
+	OEM       OEM       `yaml:"oem"`
+	Update    Update    `yaml:"update"`
+	Units     []Unit    `yaml:"units"`
+}
+
+func IsCloudConfig(userdata string) bool {
+	header := strings.SplitN(userdata, "\n", 2)[0]
+
+	// Trim trailing whitespaces
+	header = strings.TrimRightFunc(header, unicode.IsSpace)
+
+	return (header == "#cloud-config")
+}
+
+// NewCloudConfig instantiates a new CloudConfig from the given contents (a
+// string of YAML), returning any error encountered. It will ignore unknown
+// fields but log encountering them.
+func NewCloudConfig(contents string) (*CloudConfig, error) {
+	//	yaml.UnmarshalMappingKeyTransform = func(nameIn string) (nameOut string) {
+	//		return strings.Replace(nameIn, "-", "_", -1)
+	//	}
+	var cfg CloudConfig
+	err := yaml.Unmarshal([]byte(contents), &cfg)
+	return &cfg, err
+}
+
+func (cc CloudConfig) String() string {
+	bytes, err := yaml.Marshal(cc)
+	if err != nil {
+		return ""
+	}
+
+	stringified := string(bytes)
+	stringified = fmt.Sprintf("#cloud-config\n%s", stringified)
+
+	return stringified
+}
+
+// IsZero returns whether or not the parameter is the zero value for its type.
+// If the parameter is a struct, only the exported fields are considered.
+func IsZero(c interface{}) bool {
+	return isZero(reflect.ValueOf(c))
+}
+
+type ErrorValid struct {
+	Value string
+	Valid string
+	Field string
+}
+
+func (e ErrorValid) Error() string {
+	return fmt.Sprintf("invalid value %q for option %q (valid options: %q)", e.Value, e.Field, e.Valid)
+}
+
+// AssertStructValid checks the fields in the structure and makes sure that
+// they contain valid values as specified by the 'valid' flag. Empty fields are
+// implicitly valid.
+func AssertStructValid(c interface{}) error {
+	ct := reflect.TypeOf(c)
+	cv := reflect.ValueOf(c)
+	for i := 0; i < ct.NumField(); i++ {
+		ft := ct.Field(i)
+		if !isFieldExported(ft) {
+			continue
+		}
+
+		if err := AssertValid(cv.Field(i), ft.Tag.Get("valid")); err != nil {
+			err.Field = ft.Name
+			return err
+		}
+	}
+	return nil
+}
+
+// AssertValid checks to make sure that the given value is in the list of
+// valid values. Zero values are implicitly valid.
+func AssertValid(value reflect.Value, valid string) *ErrorValid {
+	if valid == "" || isZero(value) {
+		return nil
+	}
+
+	vs := fmt.Sprintf("%v", value.Interface())
+	if m, _ := regexp.MatchString(valid, vs); m {
+		return nil
+	}
+
+	return &ErrorValid{
+		Value: vs,
+		Valid: valid,
+	}
+}
+
+func isZero(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Struct:
+		vt := v.Type()
+		for i := 0; i < v.NumField(); i++ {
+			if isFieldExported(vt.Field(i)) && !isZero(v.Field(i)) {
+				return false
+			}
+		}
+		return true
+	default:
+		return v.Interface() == reflect.Zero(v.Type()).Interface()
+	}
+}
+
+func isFieldExported(f reflect.StructField) bool {
+	return f.PkgPath == ""
+}
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -0,0 +1,503 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"reflect"
+	"regexp"
+	"strings"
+	"testing"
+)
+
+func TestNewCloudConfig(t *testing.T) {
+	tests := []struct {
+		contents string
+
+		config CloudConfig
+	}{
+		{},
+		{
+			contents: "#cloud-config\nwrite_files:\n  - path: underscore",
+			config:   CloudConfig{WriteFiles: []File{File{Path: "underscore"}}},
+		},
+		{
+			contents: "#cloud-config\nwrite-files:\n  - path: hyphen",
+			config:   CloudConfig{WriteFiles: []File{File{Path: "hyphen"}}},
+		},
+		{
+			contents: "#cloud-config\ncoreos:\n  update:\n    reboot-strategy: off",
+			config:   CloudConfig{CoreOS: CoreOS{Update: Update{RebootStrategy: "off"}}},
+		},
+		{
+			contents: "#cloud-config\ncoreos:\n  update:\n    reboot-strategy: false",
+			config:   CloudConfig{CoreOS: CoreOS{Update: Update{RebootStrategy: "false"}}},
+		},
+		{
+			contents: "#cloud-config\nwrite_files:\n  - permissions: 0744",
+			config:   CloudConfig{WriteFiles: []File{File{RawFilePermissions: "0744"}}},
+		},
+		{
+			contents: "#cloud-config\nwrite_files:\n  - permissions: 744",
+			config:   CloudConfig{WriteFiles: []File{File{RawFilePermissions: "744"}}},
+		},
+		{
+			contents: "#cloud-config\nwrite_files:\n  - permissions: '0744'",
+			config:   CloudConfig{WriteFiles: []File{File{RawFilePermissions: "0744"}}},
+		},
+		{
+			contents: "#cloud-config\nwrite_files:\n  - permissions: '744'",
+			config:   CloudConfig{WriteFiles: []File{File{RawFilePermissions: "744"}}},
+		},
+	}
+
+	for i, tt := range tests {
+		config, err := NewCloudConfig(tt.contents)
+		if err != nil {
+			t.Errorf("bad error (test case #%d): want %v, got %s", i, nil, err)
+		}
+		if !reflect.DeepEqual(&tt.config, config) {
+			t.Errorf("bad config (test case #%d): want %#v, got %#v", i, tt.config, config)
+		}
+	}
+}
+
+func TestIsZero(t *testing.T) {
+	tests := []struct {
+		c interface{}
+
+		empty bool
+	}{
+		{struct{}{}, true},
+		{struct{ a, b string }{}, true},
+		{struct{ A, b string }{}, true},
+		{struct{ A, B string }{}, true},
+		{struct{ A string }{A: "hello"}, false},
+		{struct{ A int }{}, true},
+		{struct{ A int }{A: 1}, false},
+	}
+
+	for _, tt := range tests {
+		if empty := IsZero(tt.c); tt.empty != empty {
+			t.Errorf("bad result (%q): want %t, got %t", tt.c, tt.empty, empty)
+		}
+	}
+}
+
+func TestAssertStructValid(t *testing.T) {
+	tests := []struct {
+		c interface{}
+
+		err error
+	}{
+		{struct{}{}, nil},
+		{struct {
+			A, b string `valid:"^1|2$"`
+		}{}, nil},
+		{struct {
+			A, b string `valid:"^1|2$"`
+		}{A: "1", b: "2"}, nil},
+		{struct {
+			A, b string `valid:"^1|2$"`
+		}{A: "1", b: "hello"}, nil},
+		{struct {
+			A, b string `valid:"^1|2$"`
+		}{A: "hello", b: "2"}, &ErrorValid{Value: "hello", Field: "A", Valid: "^1|2$"}},
+		{struct {
+			A, b int `valid:"^1|2$"`
+		}{}, nil},
+		{struct {
+			A, b int `valid:"^1|2$"`
+		}{A: 1, b: 2}, nil},
+		{struct {
+			A, b int `valid:"^1|2$"`
+		}{A: 1, b: 9}, nil},
+		{struct {
+			A, b int `valid:"^1|2$"`
+		}{A: 9, b: 2}, &ErrorValid{Value: "9", Field: "A", Valid: "^1|2$"}},
+	}
+
+	for _, tt := range tests {
+		if err := AssertStructValid(tt.c); !reflect.DeepEqual(tt.err, err) {
+			t.Errorf("bad result (%q): want %q, got %q", tt.c, tt.err, err)
+		}
+	}
+}
+
+func TestConfigCompile(t *testing.T) {
+	tests := []interface{}{
+		Etcd{},
+		File{},
+		Flannel{},
+		Fleet{},
+		Locksmith{},
+		OEM{},
+		Unit{},
+		Update{},
+	}
+
+	for _, tt := range tests {
+		ttt := reflect.TypeOf(tt)
+		for i := 0; i < ttt.NumField(); i++ {
+			ft := ttt.Field(i)
+			if !isFieldExported(ft) {
+				continue
+			}
+
+			if _, err := regexp.Compile(ft.Tag.Get("valid")); err != nil {
+				t.Errorf("bad regexp(%s.%s): want %v, got %s", ttt.Name(), ft.Name, nil, err)
+			}
+		}
+	}
+}
+
+func TestCloudConfigUnknownKeys(t *testing.T) {
+	contents := `
+coreos: 
+  etcd:
+    discovery: "https://discovery.etcd.io/827c73219eeb2fa5530027c37bf18877"
+  coreos_unknown:
+    foo: "bar"
+section_unknown:
+  dunno:
+    something
+bare_unknown:
+  bar
+write_files:
+  - content: fun
+    path: /var/party
+    file_unknown: nofun
+users:
+  - name: fry
+    passwd: somehash
+    user_unknown: philip
+hostname:
+  foo
+`
+	cfg, err := NewCloudConfig(contents)
+	if err != nil {
+		t.Fatalf("error instantiating CloudConfig with unknown keys: %v", err)
+	}
+	if cfg.Hostname != "foo" {
+		t.Fatalf("hostname not correctly set when invalid keys are present")
+	}
+	if cfg.CoreOS.Etcd.Discovery != "https://discovery.etcd.io/827c73219eeb2fa5530027c37bf18877" {
+		t.Fatalf("etcd section not correctly set when invalid keys are present")
+	}
+	if len(cfg.WriteFiles) < 1 || cfg.WriteFiles[0].Content != "fun" || cfg.WriteFiles[0].Path != "/var/party" {
+		t.Fatalf("write_files section not correctly set when invalid keys are present")
+	}
+	if len(cfg.Users) < 1 || cfg.Users[0].Name != "fry" || cfg.Users[0].PasswordHash != "somehash" {
+		t.Fatalf("users section not correctly set when invalid keys are present")
+	}
+}
+
+// Assert that the parsing of a cloud config file "generally works"
+func TestCloudConfigEmpty(t *testing.T) {
+	cfg, err := NewCloudConfig("")
+	if err != nil {
+		t.Fatalf("Encountered unexpected error :%v", err)
+	}
+
+	keys := cfg.SSHAuthorizedKeys
+	if len(keys) != 0 {
+		t.Error("Parsed incorrect number of SSH keys")
+	}
+
+	if len(cfg.WriteFiles) != 0 {
+		t.Error("Expected zero WriteFiles")
+	}
+
+	if cfg.Hostname != "" {
+		t.Errorf("Expected hostname to be empty, got '%s'", cfg.Hostname)
+	}
+}
+
+// Assert that the parsing of a cloud config file "generally works"
+func TestCloudConfig(t *testing.T) {
+	contents := `
+coreos: 
+  etcd:
+    discovery: "https://discovery.etcd.io/827c73219eeb2fa5530027c37bf18877"
+  update:
+    reboot_strategy: reboot
+  units:
+    - name: 50-eth0.network
+      runtime: yes
+      content: '[Match]
+ 
+    Name=eth47
+ 
+ 
+    [Network]
+ 
+    Address=10.209.171.177/19
+ 
+'
+  oem:
+    id: rackspace
+    name: Rackspace Cloud Servers
+    version_id: 168.0.0
+    home_url: https://www.rackspace.com/cloud/servers/
+    bug_report_url: https://github.com/coreos/coreos-overlay
+ssh_authorized_keys:
+  - foobar
+  - foobaz
+write_files:
+  - content: |
+      penny
+      elroy
+    path: /etc/dogepack.conf
+    permissions: '0644'
+    owner: root:dogepack
+hostname: trontastic
+`
+	cfg, err := NewCloudConfig(contents)
+	if err != nil {
+		t.Fatalf("Encountered unexpected error :%v", err)
+	}
+
+	keys := cfg.SSHAuthorizedKeys
+	if len(keys) != 2 {
+		t.Error("Parsed incorrect number of SSH keys")
+	} else if keys[0] != "foobar" {
+		t.Error("Expected first SSH key to be 'foobar'")
+	} else if keys[1] != "foobaz" {
+		t.Error("Expected first SSH key to be 'foobaz'")
+	}
+
+	if len(cfg.WriteFiles) != 1 {
+		t.Error("Failed to parse correct number of write_files")
+	} else {
+		wf := cfg.WriteFiles[0]
+		if wf.Content != "penny\nelroy\n" {
+			t.Errorf("WriteFile has incorrect contents '%s'", wf.Content)
+		}
+		if wf.Encoding != "" {
+			t.Errorf("WriteFile has incorrect encoding %s", wf.Encoding)
+		}
+		if wf.RawFilePermissions != "0644" {
+			t.Errorf("WriteFile has incorrect permissions %s", wf.RawFilePermissions)
+		}
+		if wf.Path != "/etc/dogepack.conf" {
+			t.Errorf("WriteFile has incorrect path %s", wf.Path)
+		}
+		if wf.Owner != "root:dogepack" {
+			t.Errorf("WriteFile has incorrect owner %s", wf.Owner)
+		}
+	}
+
+	if len(cfg.CoreOS.Units) != 1 {
+		t.Error("Failed to parse correct number of units")
+	} else {
+		u := cfg.CoreOS.Units[0]
+		expect := `[Match]
+Name=eth47
+
+[Network]
+Address=10.209.171.177/19
+`
+		if u.Content != expect {
+			t.Errorf("Unit has incorrect contents '%s'.\nExpected '%s'.", u.Content, expect)
+		}
+		if u.Runtime != true {
+			t.Errorf("Unit has incorrect runtime value")
+		}
+		if u.Name != "50-eth0.network" {
+			t.Errorf("Unit has incorrect name %s", u.Name)
+		}
+	}
+
+	if cfg.CoreOS.OEM.ID != "rackspace" {
+		t.Errorf("Failed parsing coreos.oem. Expected ID 'rackspace', got %q.", cfg.CoreOS.OEM.ID)
+	}
+
+	if cfg.Hostname != "trontastic" {
+		t.Errorf("Failed to parse hostname")
+	}
+	if cfg.CoreOS.Update.RebootStrategy != "reboot" {
+		t.Errorf("Failed to parse locksmith strategy")
+	}
+}
+
+// Assert that our interface conversion doesn't panic
+func TestCloudConfigKeysNotList(t *testing.T) {
+	contents := `
+ssh_authorized_keys:
+  - foo: bar
+`
+	cfg, err := NewCloudConfig(contents)
+	if err != nil {
+		t.Fatalf("Encountered unexpected error: %v", err)
+	}
+
+	keys := cfg.SSHAuthorizedKeys
+	if len(keys) != 0 {
+		t.Error("Parsed incorrect number of SSH keys")
+	}
+}
+
+func TestCloudConfigSerializationHeader(t *testing.T) {
+	cfg, _ := NewCloudConfig("")
+	contents := cfg.String()
+	header := strings.SplitN(contents, "\n", 2)[0]
+	if header != "#cloud-config" {
+		t.Fatalf("Serialized config did not have expected header")
+	}
+}
+
+func TestCloudConfigUsers(t *testing.T) {
+	contents := `
+users:
+  - name: elroy
+    passwd: somehash
+    ssh_authorized_keys:
+      - somekey
+    gecos: arbitrary comment
+    homedir: /home/place
+    no_create_home: yes
+    lock_passwd: false
+    primary_group: things
+    groups:
+      - ping
+      - pong
+    no_user_group: true
+    system: y
+    no_log_init: True
+    shell: /bin/sh
+`
+	cfg, err := NewCloudConfig(contents)
+	if err != nil {
+		t.Fatalf("Encountered unexpected error: %v", err)
+	}
+
+	if len(cfg.Users) != 1 {
+		t.Fatalf("Parsed %d users, expected 1", len(cfg.Users))
+	}
+
+	user := cfg.Users[0]
+
+	if user.Name != "elroy" {
+		t.Errorf("User name is %q, expected 'elroy'", user.Name)
+	}
+
+	if user.PasswordHash != "somehash" {
+		t.Errorf("User passwd is %q, expected 'somehash'", user.PasswordHash)
+	}
+
+	if keys := user.SSHAuthorizedKeys; len(keys) != 1 {
+		t.Errorf("Parsed %d ssh keys, expected 1", len(keys))
+	} else {
+		key := user.SSHAuthorizedKeys[0]
+		if key != "somekey" {
+			t.Errorf("User SSH key is %q, expected 'somekey'", key)
+		}
+	}
+
+	if user.GECOS != "arbitrary comment" {
+		t.Errorf("Failed to parse gecos field, got %q", user.GECOS)
+	}
+
+	if user.Homedir != "/home/place" {
+		t.Errorf("Failed to parse homedir field, got %q", user.Homedir)
+	}
+
+	if !user.NoCreateHome {
+		t.Errorf("Failed to parse no_create_home field")
+	}
+
+	if user.PrimaryGroup != "things" {
+		t.Errorf("Failed to parse primary_group field, got %q", user.PrimaryGroup)
+	}
+
+	if len(user.Groups) != 2 {
+		t.Errorf("Failed to parse 2 goups, got %d", len(user.Groups))
+	} else {
+		if user.Groups[0] != "ping" {
+			t.Errorf("First group was %q, not expected value 'ping'", user.Groups[0])
+		}
+		if user.Groups[1] != "pong" {
+			t.Errorf("First group was %q, not expected value 'pong'", user.Groups[1])
+		}
+	}
+
+	if !user.NoUserGroup {
+		t.Errorf("Failed to parse no_user_group field")
+	}
+
+	if !user.System {
+		t.Errorf("Failed to parse system field")
+	}
+
+	if !user.NoLogInit {
+		t.Errorf("Failed to parse no_log_init field")
+	}
+
+	if user.Shell != "/bin/sh" {
+		t.Errorf("Failed to parse shell field, got %q", user.Shell)
+	}
+}
+
+func TestCloudConfigUsersGithubUser(t *testing.T) {
+
+	contents := `
+users:
+  - name: elroy
+    coreos_ssh_import_github: bcwaldon
+`
+	cfg, err := NewCloudConfig(contents)
+	if err != nil {
+		t.Fatalf("Encountered unexpected error: %v", err)
+	}
+
+	if len(cfg.Users) != 1 {
+		t.Fatalf("Parsed %d users, expected 1", len(cfg.Users))
+	}
+
+	user := cfg.Users[0]
+
+	if user.Name != "elroy" {
+		t.Errorf("User name is %q, expected 'elroy'", user.Name)
+	}
+
+	if user.SSHImportGithubUser != "bcwaldon" {
+		t.Errorf("github user is %q, expected 'bcwaldon'", user.SSHImportGithubUser)
+	}
+}
+
+func TestCloudConfigUsersSSHImportURL(t *testing.T) {
+	contents := `
+users:
+  - name: elroy
+    coreos_ssh_import_url: https://token:x-auth-token@github.enterprise.com/api/v3/polvi/keys
+`
+	cfg, err := NewCloudConfig(contents)
+	if err != nil {
+		t.Fatalf("Encountered unexpected error: %v", err)
+	}
+
+	if len(cfg.Users) != 1 {
+		t.Fatalf("Parsed %d users, expected 1", len(cfg.Users))
+	}
+
+	user := cfg.Users[0]
+
+	if user.Name != "elroy" {
+		t.Errorf("User name is %q, expected 'elroy'", user.Name)
+	}
+
+	if user.SSHImportURL != "https://token:x-auth-token@github.enterprise.com/api/v3/polvi/keys" {
+		t.Errorf("ssh import url is %q, expected 'https://token:x-auth-token@github.enterprise.com/api/v3/polvi/keys'", user.SSHImportURL)
+	}
+}
--- a/config/decode.go
+++ b/config/decode.go
@@ -0,0 +1,56 @@
+package config
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/base64"
+	"fmt"
+)
+
+func DecodeBase64Content(content string) ([]byte, error) {
+	output, err := base64.StdEncoding.DecodeString(content)
+
+	if err != nil {
+		return nil, fmt.Errorf("Unable to decode base64: %q", err)
+	}
+
+	return output, nil
+}
+
+func DecodeGzipContent(content string) ([]byte, error) {
+	gzr, err := gzip.NewReader(bytes.NewReader([]byte(content)))
+
+	if err != nil {
+		return nil, fmt.Errorf("Unable to decode gzip: %q", err)
+	}
+	defer gzr.Close()
+
+	buf := new(bytes.Buffer)
+	buf.ReadFrom(gzr)
+
+	return buf.Bytes(), nil
+}
+
+func DecodeContent(content string, encoding string) ([]byte, error) {
+	switch encoding {
+	case "":
+		return []byte(content), nil
+
+	case "b64", "base64":
+		return DecodeBase64Content(content)
+
+	case "gz", "gzip":
+		return DecodeGzipContent(content)
+
+	case "gz+base64", "gzip+base64", "gz+b64", "gzip+b64":
+		gz, err := DecodeBase64Content(content)
+
+		if err != nil {
+			return nil, err
+		}
+
+		return DecodeGzipContent(string(gz))
+	}
+
+	return nil, fmt.Errorf("Unsupported encoding %q", encoding)
+}
--- a/config/etc_hosts.go
+++ b/config/etc_hosts.go
@@ -0,0 +1,17 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type EtcHosts string
--- a/config/etcd.go
+++ b/config/etcd.go
@@ -0,0 +1,67 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type Etcd struct {
+	Addr                     string  `yaml:"addr"                          env:"ETCD_ADDR"`
+	AdvertiseClientURLs      string  `yaml:"advertise_client_urls"         env:"ETCD_ADVERTISE_CLIENT_URLS"       deprecated:"etcd2 options no longer work for etcd"`
+	BindAddr                 string  `yaml:"bind_addr"                     env:"ETCD_BIND_ADDR"`
+	CAFile                   string  `yaml:"ca_file"                       env:"ETCD_CA_FILE"`
+	CertFile                 string  `yaml:"cert_file"                     env:"ETCD_CERT_FILE"`
+	ClusterActiveSize        int     `yaml:"cluster_active_size"           env:"ETCD_CLUSTER_ACTIVE_SIZE"`
+	ClusterRemoveDelay       float64 `yaml:"cluster_remove_delay"          env:"ETCD_CLUSTER_REMOVE_DELAY"`
+	ClusterSyncInterval      float64 `yaml:"cluster_sync_interval"         env:"ETCD_CLUSTER_SYNC_INTERVAL"`
+	CorsOrigins              string  `yaml:"cors"                          env:"ETCD_CORS"`
+	DataDir                  string  `yaml:"data_dir"                      env:"ETCD_DATA_DIR"`
+	Discovery                string  `yaml:"discovery"                     env:"ETCD_DISCOVERY"`
+	DiscoveryFallback        string  `yaml:"discovery_fallback"            env:"ETCD_DISCOVERY_FALLBACK"          deprecated:"etcd2 options no longer work for etcd"`
+	DiscoverySRV             string  `yaml:"discovery_srv"                 env:"ETCD_DISCOVERY_SRV"               deprecated:"etcd2 options no longer work for etcd"`
+	DiscoveryProxy           string  `yaml:"discovery_proxy"               env:"ETCD_DISCOVERY_PROXY"             deprecated:"etcd2 options no longer work for etcd"`
+	ElectionTimeout          int     `yaml:"election_timeout"              env:"ETCD_ELECTION_TIMEOUT"            deprecated:"etcd2 options no longer work for etcd"`
+	ForceNewCluster          bool    `yaml:"force_new_cluster"             env:"ETCD_FORCE_NEW_CLUSTER"           deprecated:"etcd2 options no longer work for etcd"`
+	GraphiteHost             string  `yaml:"graphite_host"                 env:"ETCD_GRAPHITE_HOST"`
+	HeartbeatInterval        int     `yaml:"heartbeat_interval"            env:"ETCD_HEARTBEAT_INTERVAL"          deprecated:"etcd2 options no longer work for etcd"`
+	HTTPReadTimeout          float64 `yaml:"http_read_timeout"             env:"ETCD_HTTP_READ_TIMEOUT"`
+	HTTPWriteTimeout         float64 `yaml:"http_write_timeout"            env:"ETCD_HTTP_WRITE_TIMEOUT"`
+	InitialAdvertisePeerURLs string  `yaml:"initial_advertise_peer_urls"   env:"ETCD_INITIAL_ADVERTISE_PEER_URLS" deprecated:"etcd2 options no longer work for etcd"`
+	InitialCluster           string  `yaml:"initial_cluster"               env:"ETCD_INITIAL_CLUSTER"             deprecated:"etcd2 options no longer work for etcd"`
+	InitialClusterState      string  `yaml:"initial_cluster_state"         env:"ETCD_INITIAL_CLUSTER_STATE"       deprecated:"etcd2 options no longer work for etcd"`
+	InitialClusterToken      string  `yaml:"initial_cluster_token"         env:"ETCD_INITIAL_CLUSTER_TOKEN"       deprecated:"etcd2 options no longer work for etcd"`
+	KeyFile                  string  `yaml:"key_file"                      env:"ETCD_KEY_FILE"`
+	ListenClientURLs         string  `yaml:"listen_client_urls"            env:"ETCD_LISTEN_CLIENT_URLS"          deprecated:"etcd2 options no longer work for etcd"`
+	ListenPeerURLs           string  `yaml:"listen_peer_urls"              env:"ETCD_LISTEN_PEER_URLS"            deprecated:"etcd2 options no longer work for etcd"`
+	MaxResultBuffer          int     `yaml:"max_result_buffer"             env:"ETCD_MAX_RESULT_BUFFER"`
+	MaxRetryAttempts         int     `yaml:"max_retry_attempts"            env:"ETCD_MAX_RETRY_ATTEMPTS"`
+	MaxSnapshots             int     `yaml:"max_snapshots"                 env:"ETCD_MAX_SNAPSHOTS"               deprecated:"etcd2 options no longer work for etcd"`
+	MaxWALs                  int     `yaml:"max_wals"                      env:"ETCD_MAX_WALS"                    deprecated:"etcd2 options no longer work for etcd"`
+	Name                     string  `yaml:"name"                          env:"ETCD_NAME"`
+	PeerAddr                 string  `yaml:"peer_addr"                     env:"ETCD_PEER_ADDR"`
+	PeerBindAddr             string  `yaml:"peer_bind_addr"                env:"ETCD_PEER_BIND_ADDR"`
+	PeerCAFile               string  `yaml:"peer_ca_file"                  env:"ETCD_PEER_CA_FILE"`
+	PeerCertFile             string  `yaml:"peer_cert_file"                env:"ETCD_PEER_CERT_FILE"`
+	PeerElectionTimeout      int     `yaml:"peer_election_timeout"         env:"ETCD_PEER_ELECTION_TIMEOUT"`
+	PeerHeartbeatInterval    int     `yaml:"peer_heartbeat_interval"       env:"ETCD_PEER_HEARTBEAT_INTERVAL"`
+	PeerKeyFile              string  `yaml:"peer_key_file"                 env:"ETCD_PEER_KEY_FILE"`
+	Peers                    string  `yaml:"peers"                         env:"ETCD_PEERS"`
+	PeersFile                string  `yaml:"peers_file"                    env:"ETCD_PEERS_FILE"`
+	Proxy                    string  `yaml:"proxy"                         env:"ETCD_PROXY"                       deprecated:"etcd2 options no longer work for etcd"`
+	RetryInterval            float64 `yaml:"retry_interval"                env:"ETCD_RETRY_INTERVAL"`
+	Snapshot                 bool    `yaml:"snapshot"                      env:"ETCD_SNAPSHOT"`
+	SnapshotCount            int     `yaml:"snapshot_count"                env:"ETCD_SNAPSHOTCOUNT"`
+	StrTrace                 string  `yaml:"trace"                         env:"ETCD_TRACE"`
+	Verbose                  bool    `yaml:"verbose"                       env:"ETCD_VERBOSE"`
+	VeryVerbose              bool    `yaml:"very_verbose"                  env:"ETCD_VERY_VERBOSE"`
+	VeryVeryVerbose          bool    `yaml:"very_very_verbose"             env:"ETCD_VERY_VERY_VERBOSE"`
+}
--- a/config/etcd2.go
+++ b/config/etcd2.go
@@ -0,0 +1,57 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type Etcd2 struct {
+	AdvertiseClientURLs      string `yaml:"advertise_client_urls"         env:"ETCD_ADVERTISE_CLIENT_URLS"`
+	CAFile                   string `yaml:"ca_file"                       env:"ETCD_CA_FILE"                     deprecated:"ca_file obsoleted by trusted_ca_file and client_cert_auth"`
+	CertFile                 string `yaml:"cert_file"                     env:"ETCD_CERT_FILE"`
+	ClientCertAuth           bool   `yaml:"client_cert_auth"              env:"ETCD_CLIENT_CERT_AUTH"`
+	CorsOrigins              string `yaml:"cors"                          env:"ETCD_CORS"`
+	DataDir                  string `yaml:"data_dir"                      env:"ETCD_DATA_DIR"`
+	Debug                    bool   `yaml:"debug"                         env:"ETCD_DEBUG"`
+	Discovery                string `yaml:"discovery"                     env:"ETCD_DISCOVERY"`
+	DiscoveryFallback        string `yaml:"discovery_fallback"            env:"ETCD_DISCOVERY_FALLBACK"`
+	DiscoverySRV             string `yaml:"discovery_srv"                 env:"ETCD_DISCOVERY_SRV"`
+	DiscoveryProxy           string `yaml:"discovery_proxy"               env:"ETCD_DISCOVERY_PROXY"`
+	ElectionTimeout          int    `yaml:"election_timeout"              env:"ETCD_ELECTION_TIMEOUT"`
+	ForceNewCluster          bool   `yaml:"force_new_cluster"             env:"ETCD_FORCE_NEW_CLUSTER"`
+	HeartbeatInterval        int    `yaml:"heartbeat_interval"            env:"ETCD_HEARTBEAT_INTERVAL"`
+	InitialAdvertisePeerURLs string `yaml:"initial_advertise_peer_urls"   env:"ETCD_INITIAL_ADVERTISE_PEER_URLS"`
+	InitialCluster           string `yaml:"initial_cluster"               env:"ETCD_INITIAL_CLUSTER"`
+	InitialClusterState      string `yaml:"initial_cluster_state"         env:"ETCD_INITIAL_CLUSTER_STATE"`
+	InitialClusterToken      string `yaml:"initial_cluster_token"         env:"ETCD_INITIAL_CLUSTER_TOKEN"`
+	KeyFile                  string `yaml:"key_file"                      env:"ETCD_KEY_FILE"`
+	ListenClientURLs         string `yaml:"listen_client_urls"            env:"ETCD_LISTEN_CLIENT_URLS"`
+	ListenPeerURLs           string `yaml:"listen_peer_urls"              env:"ETCD_LISTEN_PEER_URLS"`
+	LogPackageLevels         string `yaml:"log_package_levels"            env:"ETCD_LOG_PACKAGE_LEVELS"`
+	MaxSnapshots             int    `yaml:"max_snapshots"                 env:"ETCD_MAX_SNAPSHOTS"`
+	MaxWALs                  int    `yaml:"max_wals"                      env:"ETCD_MAX_WALS"`
+	Name                     string `yaml:"name"                          env:"ETCD_NAME"`
+	PeerCAFile               string `yaml:"peer_ca_file"                  env:"ETCD_PEER_CA_FILE"                deprecated:"peer_ca_file obsoleted peer_trusted_ca_file and peer_client_cert_auth"`
+	PeerCertFile             string `yaml:"peer_cert_file"                env:"ETCD_PEER_CERT_FILE"`
+	PeerKeyFile              string `yaml:"peer_key_file"                 env:"ETCD_PEER_KEY_FILE"`
+	PeerClientCertAuth       bool   `yaml:"peer_client_cert_auth"         env:"ETCD_PEER_CLIENT_CERT_AUTH"`
+	PeerTrustedCAFile        string `yaml:"peer_trusted_ca_file"          env:"ETCD_PEER_TRUSTED_CA_FILE"`
+	Proxy                    string `yaml:"proxy"                         env:"ETCD_PROXY"                       valid:"^(on|off|readonly)$"`
+	ProxyDialTimeout         int    `yaml:"proxy_dial_timeout"            env:"ETCD_PROXY_DIAL_TIMEOUT"`
+	ProxyFailureWait         int    `yaml:"proxy_failure_wait"            env:"ETCD_PROXY_FAILURE_WAIT"`
+	ProxyReadTimeout         int    `yaml:"proxy_read_timeout"            env:"ETCD_PROXY_READ_TIMEOUT"`
+	ProxyRefreshInterval     int    `yaml:"proxy_refresh_interval"        env:"ETCD_PROXY_REFRESH_INTERVAL"`
+	ProxyWriteTimeout        int    `yaml:"proxy_write_timeout"           env:"ETCD_PROXY_WRITE_TIMEOUT"`
+	SnapshotCount            int    `yaml:"snapshot_count"                env:"ETCD_SNAPSHOT_COUNT"`
+	TrustedCAFile            string `yaml:"trusted_ca_file"               env:"ETCD_TRUSTED_CA_FILE"`
+	WalDir                   string `yaml:"wal_dir"                       env:"ETCD_WAL_DIR"`
+}
--- a/config/file.go
+++ b/config/file.go
@@ -0,0 +1,23 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type File struct {
+	Encoding           string `yaml:"encoding" valid:"^(base64|b64|gz|gzip|gz\\+base64|gzip\\+base64|gz\\+b64|gzip\\+b64)$"`
+	Content            string `yaml:"content"`
+	Owner              string `yaml:"owner"`
+	Path               string `yaml:"path"`
+	RawFilePermissions string `yaml:"permissions" valid:"^0?[0-7]{3,4}$"`
+}
--- a/config/file_test.go
+++ b/config/file_test.go
@@ -0,0 +1,69 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"testing"
+)
+
+func TestEncodingValid(t *testing.T) {
+	tests := []struct {
+		value string
+
+		isValid bool
+	}{
+		{value: "base64", isValid: true},
+		{value: "b64", isValid: true},
+		{value: "gz", isValid: true},
+		{value: "gzip", isValid: true},
+		{value: "gz+base64", isValid: true},
+		{value: "gzip+base64", isValid: true},
+		{value: "gz+b64", isValid: true},
+		{value: "gzip+b64", isValid: true},
+		{value: "gzzzzbase64", isValid: false},
+		{value: "gzipppbase64", isValid: false},
+		{value: "unknown", isValid: false},
+	}
+
+	for _, tt := range tests {
+		isValid := (nil == AssertStructValid(File{Encoding: tt.value}))
+		if tt.isValid != isValid {
+			t.Errorf("bad assert (%s): want %t, got %t", tt.value, tt.isValid, isValid)
+		}
+	}
+}
+
+func TestRawFilePermissionsValid(t *testing.T) {
+	tests := []struct {
+		value string
+
+		isValid bool
+	}{
+		{value: "744", isValid: true},
+		{value: "0744", isValid: true},
+		{value: "1744", isValid: true},
+		{value: "01744", isValid: true},
+		{value: "11744", isValid: false},
+		{value: "rwxr--r--", isValid: false},
+		{value: "800", isValid: false},
+	}
+
+	for _, tt := range tests {
+		isValid := (nil == AssertStructValid(File{RawFilePermissions: tt.value}))
+		if tt.isValid != isValid {
+			t.Errorf("bad assert (%s): want %t, got %t", tt.value, tt.isValid, isValid)
+		}
+	}
+}
--- a/config/flannel.go
+++ b/config/flannel.go
@@ -0,0 +1,27 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type Flannel struct {
+	EtcdEndpoints string `yaml:"etcd_endpoints" env:"FLANNELD_ETCD_ENDPOINTS"`
+	EtcdCAFile    string `yaml:"etcd_cafile"    env:"FLANNELD_ETCD_CAFILE"`
+	EtcdCertFile  string `yaml:"etcd_certfile"  env:"FLANNELD_ETCD_CERTFILE"`
+	EtcdKeyFile   string `yaml:"etcd_keyfile"   env:"FLANNELD_ETCD_KEYFILE"`
+	EtcdPrefix    string `yaml:"etcd_prefix"    env:"FLANNELD_ETCD_PREFIX"`
+	IPMasq        string `yaml:"ip_masq"        env:"FLANNELD_IP_MASQ"`
+	SubnetFile    string `yaml:"subnet_file"    env:"FLANNELD_SUBNET_FILE"`
+	Iface         string `yaml:"interface"      env:"FLANNELD_IFACE"`
+	PublicIP      string `yaml:"public_ip"      env:"FLANNELD_PUBLIC_IP"`
+}
--- a/config/fleet.go
+++ b/config/fleet.go
@@ -0,0 +1,33 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type Fleet struct {
+	AgentTTL                string  `yaml:"agent_ttl"                 env:"FLEET_AGENT_TTL"`
+	AuthorizedKeysFile      string  `yaml:"authorized_keys_file"      env:"FLEET_AUTHORIZED_KEYS_FILE"`
+	DisableEngine           bool    `yaml:"disable_engine"            env:"FLEET_DISABLE_ENGINE"`
+	EngineReconcileInterval float64 `yaml:"engine_reconcile_interval" env:"FLEET_ENGINE_RECONCILE_INTERVAL"`
+	EtcdCAFile              string  `yaml:"etcd_cafile"               env:"FLEET_ETCD_CAFILE"`
+	EtcdCertFile            string  `yaml:"etcd_certfile"             env:"FLEET_ETCD_CERTFILE"`
+	EtcdKeyFile             string  `yaml:"etcd_keyfile"              env:"FLEET_ETCD_KEYFILE"`
+	EtcdKeyPrefix           string  `yaml:"etcd_key_prefix"           env:"FLEET_ETCD_KEY_PREFIX"`
+	EtcdRequestTimeout      float64 `yaml:"etcd_request_timeout"      env:"FLEET_ETCD_REQUEST_TIMEOUT"`
+	EtcdServers             string  `yaml:"etcd_servers"              env:"FLEET_ETCD_SERVERS"`
+	Metadata                string  `yaml:"metadata"                  env:"FLEET_METADATA"`
+	PublicIP                string  `yaml:"public_ip"                 env:"FLEET_PUBLIC_IP"`
+	TokenLimit              int     `yaml:"token_limit"               env:"FLEET_TOKEN_LIMIT"`
+	Verbosity               int     `yaml:"verbosity"                 env:"FLEET_VERBOSITY"`
+	VerifyUnits             bool    `yaml:"verify_units"              env:"FLEET_VERIFY_UNITS"`
+}
--- a/config/ignition.go
+++ b/config/ignition.go
@@ -0,0 +1,26 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"encoding/json"
+)
+
+func IsIgnitionConfig(userdata string) bool {
+	var cfg struct {
+		Version *int `json:"ignitionVersion" yaml:"ignition_version"`
+	}
+	return (json.Unmarshal([]byte(userdata), &cfg) == nil && cfg.Version != nil)
+}
--- a/config/locksmith.go
+++ b/config/locksmith.go
@@ -0,0 +1,25 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type Locksmith struct {
+	Endpoint           string `yaml:"endpoint"      env:"LOCKSMITHD_ENDPOINT"`
+	EtcdCAFile         string `yaml:"etcd_cafile"   env:"LOCKSMITHD_ETCD_CAFILE"`
+	EtcdCertFile       string `yaml:"etcd_certfile" env:"LOCKSMITHD_ETCD_CERTFILE"`
+	EtcdKeyFile        string `yaml:"etcd_keyfile"  env:"LOCKSMITHD_ETCD_KEYFILE"`
+	Group              string `yaml:"group"         env:"LOCKSMITHD_GROUP"`
+	RebootWindowStart  string `yaml:"window_start"  env:"REBOOT_WINDOW_START"  valid:"^((?i:sun|mon|tue|wed|thu|fri|sat|sun) )?0*([0-9]|1[0-9]|2[0-3]):0*([0-9]|[1-5][0-9])$"`
+	RebootWindowLength string `yaml:"window_length" env:"REBOOT_WINDOW_LENGTH" valid:"^[-+]?([0-9]*(\\.[0-9]*)?[a-z]+)+$"`
+}
--- a/config/locksmith_test.go
+++ b/config/locksmith_test.go
@@ -0,0 +1,76 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"testing"
+)
+
+func TestRebootWindowStart(t *testing.T) {
+	tests := []struct {
+		value string
+
+		isValid bool
+	}{
+		{value: "Sun 0:0", isValid: true},
+		{value: "Sun 00:00", isValid: true},
+		{value: "sUn 23:59", isValid: true},
+		{value: "mon 0:0", isValid: true},
+		{value: "tue 0:0", isValid: true},
+		{value: "tues 0:0", isValid: false},
+		{value: "wed 0:0", isValid: true},
+		{value: "thu 0:0", isValid: true},
+		{value: "thur 0:0", isValid: false},
+		{value: "fri 0:0", isValid: true},
+		{value: "sat 0:0", isValid: true},
+		{value: "sat00:00", isValid: false},
+		{value: "00:00", isValid: true},
+		{value: "10:10", isValid: true},
+		{value: "20:20", isValid: true},
+		{value: "20:30", isValid: true},
+		{value: "20:40", isValid: true},
+		{value: "20:50", isValid: true},
+		{value: "20:60", isValid: false},
+		{value: "24:00", isValid: false},
+	}
+
+	for _, tt := range tests {
+		isValid := (nil == AssertStructValid(Locksmith{RebootWindowStart: tt.value}))
+		if tt.isValid != isValid {
+			t.Errorf("bad assert (%s): want %t, got %t", tt.value, tt.isValid, isValid)
+		}
+	}
+}
+
+func TestRebootWindowLength(t *testing.T) {
+	tests := []struct {
+		value string
+
+		isValid bool
+	}{
+		{value: "1h", isValid: true},
+		{value: "1d", isValid: true},
+		{value: "0d", isValid: true},
+		{value: "0.5h", isValid: true},
+		{value: "0.5.0h", isValid: false},
+	}
+
+	for _, tt := range tests {
+		isValid := (nil == AssertStructValid(Locksmith{RebootWindowLength: tt.value}))
+		if tt.isValid != isValid {
+			t.Errorf("bad assert (%s): want %t, got %t", tt.value, tt.isValid, isValid)
+		}
+	}
+}
--- a/config/oem.go
+++ b/config/oem.go
@@ -0,0 +1,23 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type OEM struct {
+	ID           string `yaml:"id"`
+	Name         string `yaml:"name"`
+	VersionID    string `yaml:"version_id"`
+	HomeURL      string `yaml:"home_url"`
+	BugReportURL string `yaml:"bug_report_url"`
+}
--- a/config/script.go
+++ b/config/script.go
@@ -0,0 +1,31 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"strings"
+)
+
+type Script []byte
+
+func IsScript(userdata string) bool {
+	header := strings.SplitN(userdata, "\n", 2)[0]
+	return strings.HasPrefix(header, "#!")
+}
+
+func NewScript(userdata string) (*Script, error) {
+	s := Script(userdata)
+	return &s, nil
+}
--- a/config/system_info.go
+++ b/config/system_info.go
@@ -0,0 +1,7 @@
+package config
+
+type SystemInfo struct {
+	DefaultUser struct {
+		Name string `yaml:"name"`
+	} `yaml:"default_user"`
+}
--- a/config/unit.go
+++ b/config/unit.go
@@ -0,0 +1,30 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type Unit struct {
+	Name    string       `yaml:"name"`
+	Mask    bool         `yaml:"mask"`
+	Enable  bool         `yaml:"enable"`
+	Runtime bool         `yaml:"runtime"`
+	Content string       `yaml:"content"`
+	Command string       `yaml:"command" valid:"^(start|stop|restart|reload|try-restart|reload-or-restart|reload-or-try-restart)$"`
+	DropIns []UnitDropIn `yaml:"drop_ins"`
+}
+
+type UnitDropIn struct {
+	Name    string `yaml:"name"`
+	Content string `yaml:"content"`
+}
--- a/config/unit_test.go
+++ b/config/unit_test.go
@@ -0,0 +1,46 @@
+/*
+   Copyright 2014 CoreOS, Inc.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package config
+
+import (
+	"testing"
+)
+
+func TestCommandValid(t *testing.T) {
+	tests := []struct {
+		value string
+
+		isValid bool
+	}{
+		{value: "start", isValid: true},
+		{value: "stop", isValid: true},
+		{value: "restart", isValid: true},
+		{value: "reload", isValid: true},
+		{value: "try-restart", isValid: true},
+		{value: "reload-or-restart", isValid: true},
+		{value: "reload-or-try-restart", isValid: true},
+		{value: "tryrestart", isValid: false},
+		{value: "unknown", isValid: false},
+	}
+
+	for _, tt := range tests {
+		isValid := (nil == AssertStructValid(Unit{Command: tt.value}))
+		if tt.isValid != isValid {
+			t.Errorf("bad assert (%s): want %t, got %t", tt.value, tt.isValid, isValid)
+		}
+	}
+}
--- a/config/update.go
+++ b/config/update.go
@@ -0,0 +1,21 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type Update struct {
+	RebootStrategy string `yaml:"reboot_strategy" env:"REBOOT_STRATEGY" valid:"^(best-effort|etcd-lock|reboot|off)$"`
+	Group          string `yaml:"group"           env:"GROUP"`
+	Server         string `yaml:"server"          env:"SERVER"`
+}
--- a/config/update_test.go
+++ b/config/update_test.go
@@ -0,0 +1,43 @@
+/*
+   Copyright 2014 CoreOS, Inc.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package config
+
+import (
+	"testing"
+)
+
+func TestRebootStrategyValid(t *testing.T) {
+	tests := []struct {
+		value string
+
+		isValid bool
+	}{
+		{value: "best-effort", isValid: true},
+		{value: "etcd-lock", isValid: true},
+		{value: "reboot", isValid: true},
+		{value: "off", isValid: true},
+		{value: "besteffort", isValid: false},
+		{value: "unknown", isValid: false},
+	}
+
+	for _, tt := range tests {
+		isValid := (nil == AssertStructValid(Update{RebootStrategy: tt.value}))
+		if tt.isValid != isValid {
+			t.Errorf("bad assert (%s): want %t, got %t", tt.value, tt.isValid, isValid)
+		}
+	}
+}
--- a/config/user.go
+++ b/config/user.go
@@ -0,0 +1,34 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+type User struct {
+	Name                 string   `yaml:"name"`
+	PasswordHash         string   `yaml:"passwd"`
+	SSHAuthorizedKeys    []string `yaml:"ssh_authorized_keys"`
+	SSHImportGithubUser  string   `yaml:"coreos_ssh_import_github"       deprecated:"trying to fetch from a remote endpoint introduces too many intermittent errors"`
+	SSHImportGithubUsers []string `yaml:"coreos_ssh_import_github_users" deprecated:"trying to fetch from a remote endpoint introduces too many intermittent errors"`
+	SSHImportURL         string   `yaml:"coreos_ssh_import_url"          deprecated:"trying to fetch from a remote endpoint introduces too many intermittent errors"`
+	GECOS                string   `yaml:"gecos"`
+	Homedir              string   `yaml:"homedir"`
+	NoCreateHome         bool     `yaml:"no_create_home"`
+	PrimaryGroup         string   `yaml:"primary_group"`
+	Groups               []string `yaml:"groups"`
+	NoUserGroup          bool     `yaml:"no_user_group"`
+	System               bool     `yaml:"system"`
+	NoLogInit            bool     `yaml:"no_log_init"`
+	LockPasswd           bool     `yaml:"lock_passwd"`
+	Shell                string   `yaml:"shell"`
+}
--- a/config/validate/context.go
+++ b/config/validate/context.go
@@ -0,0 +1,52 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"strings"
+)
+
+// context represents the current position within a newline-delimited string.
+// Each line is loaded, one by one, into currentLine (newline omitted) and
+// lineNumber keeps track of its position within the original string.
+type context struct {
+	currentLine    string
+	remainingLines string
+	lineNumber     int
+}
+
+// Increment moves the context to the next line (if available).
+func (c *context) Increment() {
+	if c.currentLine == "" && c.remainingLines == "" {
+		return
+	}
+
+	lines := strings.SplitN(c.remainingLines, "\n", 2)
+	c.currentLine = lines[0]
+	if len(lines) == 2 {
+		c.remainingLines = lines[1]
+	} else {
+		c.remainingLines = ""
+	}
+	c.lineNumber++
+}
+
+// NewContext creates a context from the provided data. It strips out all
+// carriage returns and moves to the first line (if available).
+func NewContext(content []byte) context {
+	c := context{remainingLines: strings.Replace(string(content), "\r", "", -1)}
+	c.Increment()
+	return c
+}
--- a/config/validate/context_test.go
+++ b/config/validate/context_test.go
@@ -0,0 +1,131 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestNewContext(t *testing.T) {
+	tests := []struct {
+		in string
+
+		out context
+	}{
+		{
+			out: context{
+				currentLine:    "",
+				remainingLines: "",
+				lineNumber:     0,
+			},
+		},
+		{
+			in: "this\r\nis\r\na\r\ntest",
+			out: context{
+				currentLine:    "this",
+				remainingLines: "is\na\ntest",
+				lineNumber:     1,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		if out := NewContext([]byte(tt.in)); !reflect.DeepEqual(tt.out, out) {
+			t.Errorf("bad context (%q): want %#v, got %#v", tt.in, tt.out, out)
+		}
+	}
+}
+
+func TestIncrement(t *testing.T) {
+	tests := []struct {
+		init context
+		op   func(c *context)
+
+		res context
+	}{
+		{
+			init: context{
+				currentLine:    "",
+				remainingLines: "",
+				lineNumber:     0,
+			},
+			res: context{
+				currentLine:    "",
+				remainingLines: "",
+				lineNumber:     0,
+			},
+			op: func(c *context) {
+				c.Increment()
+			},
+		},
+		{
+			init: context{
+				currentLine:    "test",
+				remainingLines: "",
+				lineNumber:     1,
+			},
+			res: context{
+				currentLine:    "",
+				remainingLines: "",
+				lineNumber:     2,
+			},
+			op: func(c *context) {
+				c.Increment()
+				c.Increment()
+				c.Increment()
+			},
+		},
+		{
+			init: context{
+				currentLine:    "this",
+				remainingLines: "is\na\ntest",
+				lineNumber:     1,
+			},
+			res: context{
+				currentLine:    "is",
+				remainingLines: "a\ntest",
+				lineNumber:     2,
+			},
+			op: func(c *context) {
+				c.Increment()
+			},
+		},
+		{
+			init: context{
+				currentLine:    "this",
+				remainingLines: "is\na\ntest",
+				lineNumber:     1,
+			},
+			res: context{
+				currentLine:    "test",
+				remainingLines: "",
+				lineNumber:     4,
+			},
+			op: func(c *context) {
+				c.Increment()
+				c.Increment()
+				c.Increment()
+			},
+		},
+	}
+
+	for i, tt := range tests {
+		res := tt.init
+		if tt.op(&res); !reflect.DeepEqual(tt.res, res) {
+			t.Errorf("bad context (%d, %#v): want %#v, got %#v", i, tt.init, tt.res, res)
+		}
+	}
+}
--- a/config/validate/node.go
+++ b/config/validate/node.go
@@ -0,0 +1,157 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"fmt"
+	"reflect"
+	"regexp"
+)
+
+var (
+	yamlKey  = regexp.MustCompile(`^ *-? ?(?P<key>.*?):`)
+	yamlElem = regexp.MustCompile(`^ *-`)
+)
+
+type node struct {
+	name     string
+	line     int
+	children []node
+	field    reflect.StructField
+	reflect.Value
+}
+
+// Child attempts to find the child with the given name in the node's list of
+// children. If no such child is found, an invalid node is returned.
+func (n node) Child(name string) node {
+	for _, c := range n.children {
+		if c.name == name {
+			return c
+		}
+	}
+	return node{}
+}
+
+// HumanType returns the human-consumable string representation of the type of
+// the node.
+func (n node) HumanType() string {
+	switch k := n.Kind(); k {
+	case reflect.Slice:
+		c := n.Type().Elem()
+		return "[]" + node{Value: reflect.New(c).Elem()}.HumanType()
+	default:
+		return k.String()
+	}
+}
+
+// NewNode returns the node representation of the given value. The context
+// will be used in an attempt to determine line numbers for the given value.
+func NewNode(value interface{}, context context) node {
+	var n node
+	toNode(value, context, &n)
+	return n
+}
+
+// toNode converts the given value into a node and then recursively processes
+// each of the nodes components (e.g. fields, array elements, keys).
+func toNode(v interface{}, c context, n *node) {
+	vv := reflect.ValueOf(v)
+	if !vv.IsValid() {
+		return
+	}
+
+	n.Value = vv
+	switch vv.Kind() {
+	case reflect.Struct:
+		// Walk over each field in the structure, skipping unexported fields,
+		// and create a node for it.
+		for i := 0; i < vv.Type().NumField(); i++ {
+			ft := vv.Type().Field(i)
+			k := ft.Tag.Get("yaml")
+			if k == "-" || k == "" {
+				continue
+			}
+
+			cn := node{name: k, field: ft}
+			c, ok := findKey(cn.name, c)
+			if ok {
+				cn.line = c.lineNumber
+			}
+			toNode(vv.Field(i).Interface(), c, &cn)
+			n.children = append(n.children, cn)
+		}
+	case reflect.Map:
+		// Walk over each key in the map and create a node for it.
+		v := v.(map[interface{}]interface{})
+		for k, cv := range v {
+			cn := node{name: fmt.Sprintf("%s", k)}
+			c, ok := findKey(cn.name, c)
+			if ok {
+				cn.line = c.lineNumber
+			}
+			toNode(cv, c, &cn)
+			n.children = append(n.children, cn)
+		}
+	case reflect.Slice:
+		// Walk over each element in the slice and create a node for it.
+		// While iterating over the slice, preserve the context after it
+		// is modified. This allows the line numbers to reflect the current
+		// element instead of the first.
+		for i := 0; i < vv.Len(); i++ {
+			cn := node{
+				name:  fmt.Sprintf("%s[%d]", n.name, i),
+				field: n.field,
+			}
+			var ok bool
+			c, ok = findElem(c)
+			if ok {
+				cn.line = c.lineNumber
+			}
+			toNode(vv.Index(i).Interface(), c, &cn)
+			n.children = append(n.children, cn)
+			c.Increment()
+		}
+	case reflect.String, reflect.Int, reflect.Bool, reflect.Float64:
+	default:
+		panic(fmt.Sprintf("toNode(): unhandled kind %s", vv.Kind()))
+	}
+}
+
+// findKey attempts to find the requested key within the provided context.
+// A modified copy of the context is returned with every line up to the key
+// incremented past. A boolean, true if the key was found, is also returned.
+func findKey(key string, context context) (context, bool) {
+	return find(yamlKey, key, context)
+}
+
+// findElem attempts to find an array element within the provided context.
+// A modified copy of the context is returned with every line up to the array
+// element incremented past. A boolean, true if the key was found, is also
+// returned.
+func findElem(context context) (context, bool) {
+	return find(yamlElem, "", context)
+}
+
+func find(exp *regexp.Regexp, key string, context context) (context, bool) {
+	for len(context.currentLine) > 0 || len(context.remainingLines) > 0 {
+		matches := exp.FindStringSubmatch(context.currentLine)
+		if len(matches) > 0 && (key == "" || matches[1] == key) {
+			return context, true
+		}
+
+		context.Increment()
+	}
+	return context, false
+}
--- a/config/validate/node_test.go
+++ b/config/validate/node_test.go
@@ -0,0 +1,284 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestChild(t *testing.T) {
+	tests := []struct {
+		parent node
+		name   string
+
+		child node
+	}{
+		{},
+		{
+			name: "c1",
+		},
+		{
+			parent: node{
+				children: []node{
+					node{name: "c1"},
+					node{name: "c2"},
+					node{name: "c3"},
+				},
+			},
+		},
+		{
+			parent: node{
+				children: []node{
+					node{name: "c1"},
+					node{name: "c2"},
+					node{name: "c3"},
+				},
+			},
+			name:  "c2",
+			child: node{name: "c2"},
+		},
+	}
+
+	for _, tt := range tests {
+		if child := tt.parent.Child(tt.name); !reflect.DeepEqual(tt.child, child) {
+			t.Errorf("bad child (%q): want %#v, got %#v", tt.name, tt.child, child)
+		}
+	}
+}
+
+func TestHumanType(t *testing.T) {
+	tests := []struct {
+		node node
+
+		humanType string
+	}{
+		{
+			humanType: "invalid",
+		},
+		{
+			node:      node{Value: reflect.ValueOf("hello")},
+			humanType: "string",
+		},
+		{
+			node: node{
+				Value: reflect.ValueOf([]int{1, 2}),
+				children: []node{
+					node{Value: reflect.ValueOf(1)},
+					node{Value: reflect.ValueOf(2)},
+				}},
+			humanType: "[]int",
+		},
+	}
+
+	for _, tt := range tests {
+		if humanType := tt.node.HumanType(); tt.humanType != humanType {
+			t.Errorf("bad type (%q): want %q, got %q", tt.node, tt.humanType, humanType)
+		}
+	}
+}
+
+func TestToNode(t *testing.T) {
+	tests := []struct {
+		value   interface{}
+		context context
+
+		node node
+	}{
+		{},
+		{
+			value: struct{}{},
+			node:  node{Value: reflect.ValueOf(struct{}{})},
+		},
+		{
+			value: struct {
+				A int `yaml:"a"`
+			}{},
+			node: node{
+				children: []node{
+					node{
+						name: "a",
+						field: reflect.TypeOf(struct {
+							A int `yaml:"a"`
+						}{}).Field(0),
+					},
+				},
+			},
+		},
+		{
+			value: struct {
+				A []int `yaml:"a"`
+			}{},
+			node: node{
+				children: []node{
+					node{
+						name: "a",
+						field: reflect.TypeOf(struct {
+							A []int `yaml:"a"`
+						}{}).Field(0),
+					},
+				},
+			},
+		},
+		{
+			value: map[interface{}]interface{}{
+				"a": map[interface{}]interface{}{
+					"b": 2,
+				},
+			},
+			context: NewContext([]byte("a:\n  b: 2")),
+			node: node{
+				children: []node{
+					node{
+						line: 1,
+						name: "a",
+						children: []node{
+							node{name: "b", line: 2},
+						},
+					},
+				},
+			},
+		},
+		{
+			value: struct {
+				A struct {
+					Jon bool `yaml:"b"`
+				} `yaml:"a"`
+			}{},
+			node: node{
+				children: []node{
+					node{
+						name: "a",
+						children: []node{
+							node{
+								name: "b",
+								field: reflect.TypeOf(struct {
+									Jon bool `yaml:"b"`
+								}{}).Field(0),
+								Value: reflect.ValueOf(false),
+							},
+						},
+						field: reflect.TypeOf(struct {
+							A struct {
+								Jon bool `yaml:"b"`
+							} `yaml:"a"`
+						}{}).Field(0),
+						Value: reflect.ValueOf(struct {
+							Jon bool `yaml:"b"`
+						}{}),
+					},
+				},
+				Value: reflect.ValueOf(struct {
+					A struct {
+						Jon bool `yaml:"b"`
+					} `yaml:"a"`
+				}{}),
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		var node node
+		toNode(tt.value, tt.context, &node)
+		if !nodesEqual(tt.node, node) {
+			t.Errorf("bad node (%#v): want %#v, got %#v", tt.value, tt.node, node)
+		}
+	}
+}
+
+func TestFindKey(t *testing.T) {
+	tests := []struct {
+		key     string
+		context context
+
+		found bool
+	}{
+		{},
+		{
+			key:     "key1",
+			context: NewContext([]byte("key1: hi")),
+			found:   true,
+		},
+		{
+			key:     "key2",
+			context: NewContext([]byte("key1: hi")),
+			found:   false,
+		},
+		{
+			key:     "key3",
+			context: NewContext([]byte("key1:\n  key2:\n    key3: hi")),
+			found:   true,
+		},
+		{
+			key:     "key4",
+			context: NewContext([]byte("key1:\n  - key4: hi")),
+			found:   true,
+		},
+		{
+			key:     "key5",
+			context: NewContext([]byte("#key5")),
+			found:   false,
+		},
+	}
+
+	for _, tt := range tests {
+		if _, found := findKey(tt.key, tt.context); tt.found != found {
+			t.Errorf("bad find (%q): want %t, got %t", tt.key, tt.found, found)
+		}
+	}
+}
+
+func TestFindElem(t *testing.T) {
+	tests := []struct {
+		context context
+
+		found bool
+	}{
+		{},
+		{
+			context: NewContext([]byte("test: hi")),
+			found:   false,
+		},
+		{
+			context: NewContext([]byte("test:\n  - a\n  -b")),
+			found:   true,
+		},
+		{
+			context: NewContext([]byte("test:\n  -\n    a")),
+			found:   true,
+		},
+	}
+
+	for _, tt := range tests {
+		if _, found := findElem(tt.context); tt.found != found {
+			t.Errorf("bad find (%q): want %t, got %t", tt.context, tt.found, found)
+		}
+	}
+}
+
+func nodesEqual(a, b node) bool {
+	if a.name != b.name ||
+		a.line != b.line ||
+		!reflect.DeepEqual(a.field, b.field) ||
+		len(a.children) != len(b.children) {
+		return false
+	}
+	for i := 0; i < len(a.children); i++ {
+		if !nodesEqual(a.children[i], b.children[i]) {
+			return false
+		}
+	}
+	return true
+}
--- a/config/validate/report.go
+++ b/config/validate/report.go
@@ -0,0 +1,88 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// Report represents the list of entries resulting from validation.
+type Report struct {
+	entries []Entry
+}
+
+// Error adds an error entry to the report.
+func (r *Report) Error(line int, message string) {
+	r.entries = append(r.entries, Entry{entryError, message, line})
+}
+
+// Warning adds a warning entry to the report.
+func (r *Report) Warning(line int, message string) {
+	r.entries = append(r.entries, Entry{entryWarning, message, line})
+}
+
+// Info adds an info entry to the report.
+func (r *Report) Info(line int, message string) {
+	r.entries = append(r.entries, Entry{entryInfo, message, line})
+}
+
+// Entries returns the list of entries in the report.
+func (r *Report) Entries() []Entry {
+	return r.entries
+}
+
+// Entry represents a single generic item in the report.
+type Entry struct {
+	kind    entryKind
+	message string
+	line    int
+}
+
+// String returns a human-readable representation of the entry.
+func (e Entry) String() string {
+	return fmt.Sprintf("line %d: %s: %s", e.line, e.kind, e.message)
+}
+
+// MarshalJSON satisfies the json.Marshaler interface, returning the entry
+// encoded as a JSON object.
+func (e Entry) MarshalJSON() ([]byte, error) {
+	return json.Marshal(map[string]interface{}{
+		"kind":    e.kind.String(),
+		"message": e.message,
+		"line":    e.line,
+	})
+}
+
+type entryKind int
+
+const (
+	entryError entryKind = iota
+	entryWarning
+	entryInfo
+)
+
+func (k entryKind) String() string {
+	switch k {
+	case entryError:
+		return "error"
+	case entryWarning:
+		return "warning"
+	case entryInfo:
+		return "info"
+	default:
+		panic(fmt.Sprintf("invalid kind %d", k))
+	}
+}
--- a/config/validate/report_test.go
+++ b/config/validate/report_test.go
@@ -0,0 +1,96 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"bytes"
+	"reflect"
+	"testing"
+)
+
+func TestEntry(t *testing.T) {
+	tests := []struct {
+		entry Entry
+
+		str  string
+		json []byte
+	}{
+		{
+			Entry{entryInfo, "test info", 1},
+			"line 1: info: test info",
+			[]byte(`{"kind":"info","line":1,"message":"test info"}`),
+		},
+		{
+			Entry{entryWarning, "test warning", 1},
+			"line 1: warning: test warning",
+			[]byte(`{"kind":"warning","line":1,"message":"test warning"}`),
+		},
+		{
+			Entry{entryError, "test error", 2},
+			"line 2: error: test error",
+			[]byte(`{"kind":"error","line":2,"message":"test error"}`),
+		},
+	}
+
+	for _, tt := range tests {
+		if str := tt.entry.String(); tt.str != str {
+			t.Errorf("bad string (%q): want %q, got %q", tt.entry, tt.str, str)
+		}
+		json, err := tt.entry.MarshalJSON()
+		if err != nil {
+			t.Errorf("bad error (%q): want %v, got %q", tt.entry, nil, err)
+		}
+		if !bytes.Equal(tt.json, json) {
+			t.Errorf("bad JSON (%q): want %q, got %q", tt.entry, tt.json, json)
+		}
+	}
+}
+
+func TestReport(t *testing.T) {
+	type reportFunc struct {
+		fn      func(*Report, int, string)
+		line    int
+		message string
+	}
+
+	tests := []struct {
+		fs []reportFunc
+
+		es []Entry
+	}{
+		{
+			[]reportFunc{
+				{(*Report).Warning, 1, "test warning 1"},
+				{(*Report).Error, 2, "test error 2"},
+				{(*Report).Info, 10, "test info 10"},
+			},
+			[]Entry{
+				Entry{entryWarning, "test warning 1", 1},
+				Entry{entryError, "test error 2", 2},
+				Entry{entryInfo, "test info 10", 10},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		r := Report{}
+		for _, f := range tt.fs {
+			f.fn(&r, f.line, f.message)
+		}
+		if es := r.Entries(); !reflect.DeepEqual(tt.es, es) {
+			t.Errorf("bad entries (%v): want %#v, got %#v", tt.fs, tt.es, es)
+		}
+	}
+}
--- a/config/validate/rules.go
+++ b/config/validate/rules.go
@@ -0,0 +1,180 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"fmt"
+	"net/url"
+	"path"
+	"reflect"
+	"strings"
+
+	"github.com/coreos/coreos-cloudinit/config"
+)
+
+type rule func(config node, report *Report)
+
+// Rules contains all of the validation rules.
+var Rules []rule = []rule{
+	checkDiscoveryUrl,
+	checkEncoding,
+	checkStructure,
+	checkValidity,
+	checkWriteFiles,
+	checkWriteFilesUnderCoreos,
+}
+
+// checkDiscoveryUrl verifies that the string is a valid url.
+func checkDiscoveryUrl(cfg node, report *Report) {
+	c := cfg.Child("coreos").Child("etcd").Child("discovery")
+	if !c.IsValid() {
+		return
+	}
+
+	if _, err := url.ParseRequestURI(c.String()); err != nil {
+		report.Warning(c.line, "discovery URL is not valid")
+	}
+}
+
+// checkEncoding validates that, for each file under 'write_files', the
+// content can be decoded given the specified encoding.
+func checkEncoding(cfg node, report *Report) {
+	for _, f := range cfg.Child("write_files").children {
+		e := f.Child("encoding")
+		if !e.IsValid() {
+			continue
+		}
+
+		c := f.Child("content")
+		if _, err := config.DecodeContent(c.String(), e.String()); err != nil {
+			report.Error(c.line, fmt.Sprintf("content cannot be decoded as %q", e.String()))
+		}
+	}
+}
+
+// checkStructure compares the provided config to the empty config.CloudConfig
+// structure. Each node is checked to make sure that it exists in the known
+// structure and that its type is compatible.
+func checkStructure(cfg node, report *Report) {
+	g := NewNode(config.CloudConfig{}, NewContext([]byte{}))
+	checkNodeStructure(cfg, g, report)
+}
+
+func checkNodeStructure(n, g node, r *Report) {
+	if !isCompatible(n.Kind(), g.Kind()) {
+		r.Warning(n.line, fmt.Sprintf("incorrect type for %q (want %s)", n.name, g.HumanType()))
+		return
+	}
+
+	switch g.Kind() {
+	case reflect.Struct:
+		for _, cn := range n.children {
+			if cg := g.Child(cn.name); cg.IsValid() {
+				if msg := cg.field.Tag.Get("deprecated"); msg != "" {
+					r.Warning(cn.line, fmt.Sprintf("deprecated key %q (%s)", cn.name, msg))
+				}
+				checkNodeStructure(cn, cg, r)
+			} else {
+				r.Warning(cn.line, fmt.Sprintf("unrecognized key %q", cn.name))
+			}
+		}
+	case reflect.Slice:
+		for _, cn := range n.children {
+			var cg node
+			c := g.Type().Elem()
+			toNode(reflect.New(c).Elem().Interface(), context{}, &cg)
+			checkNodeStructure(cn, cg, r)
+		}
+	case reflect.String, reflect.Int, reflect.Float64, reflect.Bool:
+	default:
+		panic(fmt.Sprintf("checkNodeStructure(): unhandled kind %s", g.Kind()))
+	}
+}
+
+// isCompatible determines if the type of kind n can be converted to the type
+// of kind g in the context of YAML. This is not an exhaustive list, but its
+// enough for the purposes of cloud-config validation.
+func isCompatible(n, g reflect.Kind) bool {
+	switch g {
+	case reflect.String:
+		return n == reflect.String || n == reflect.Int || n == reflect.Float64 || n == reflect.Bool
+	case reflect.Struct:
+		return n == reflect.Struct || n == reflect.Map
+	case reflect.Float64:
+		return n == reflect.Float64 || n == reflect.Int
+	case reflect.Bool, reflect.Slice, reflect.Int:
+		return n == g
+	default:
+		panic(fmt.Sprintf("isCompatible(): unhandled kind %s", g))
+	}
+}
+
+// checkValidity checks the value of every node in the provided config by
+// running config.AssertValid() on it.
+func checkValidity(cfg node, report *Report) {
+	g := NewNode(config.CloudConfig{}, NewContext([]byte{}))
+	checkNodeValidity(cfg, g, report)
+}
+
+func checkNodeValidity(n, g node, r *Report) {
+	if err := config.AssertValid(n.Value, g.field.Tag.Get("valid")); err != nil {
+		r.Error(n.line, fmt.Sprintf("invalid value %v", n.Value.Interface()))
+	}
+	switch g.Kind() {
+	case reflect.Struct:
+		for _, cn := range n.children {
+			if cg := g.Child(cn.name); cg.IsValid() {
+				checkNodeValidity(cn, cg, r)
+			}
+		}
+	case reflect.Slice:
+		for _, cn := range n.children {
+			var cg node
+			c := g.Type().Elem()
+			toNode(reflect.New(c).Elem().Interface(), context{}, &cg)
+			checkNodeValidity(cn, cg, r)
+		}
+	case reflect.String, reflect.Int, reflect.Float64, reflect.Bool:
+	default:
+		panic(fmt.Sprintf("checkNodeValidity(): unhandled kind %s", g.Kind()))
+	}
+}
+
+// checkWriteFiles checks to make sure that the target file can actually be
+// written. Note that this check is approximate (it only checks to see if the file
+// is under /usr).
+func checkWriteFiles(cfg node, report *Report) {
+	for _, f := range cfg.Child("write_files").children {
+		c := f.Child("path")
+		if !c.IsValid() {
+			continue
+		}
+
+		d := path.Dir(c.String())
+		switch {
+		case strings.HasPrefix(d, "/usr"):
+			report.Error(c.line, "file cannot be written to a read-only filesystem")
+		}
+	}
+}
+
+// checkWriteFilesUnderCoreos checks to see if the 'write_files' node is a
+// child of 'coreos' (it shouldn't be).
+func checkWriteFilesUnderCoreos(cfg node, report *Report) {
+	c := cfg.Child("coreos").Child("write_files")
+	if c.IsValid() {
+		report.Info(c.line, "write_files doesn't belong under coreos")
+	}
+}
--- a/config/validate/rules_test.go
+++ b/config/validate/rules_test.go
@@ -0,0 +1,408 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestCheckDiscoveryUrl(t *testing.T) {
+	tests := []struct {
+		config string
+
+		entries []Entry
+	}{
+		{},
+		{
+			config: "coreos:\n  etcd:\n    discovery: https://discovery.etcd.io/00000000000000000000000000000000",
+		},
+		{
+			config: "coreos:\n  etcd:\n    discovery: http://custom.domain/mytoken",
+		},
+		{
+			config:  "coreos:\n  etcd:\n    discovery: disco",
+			entries: []Entry{{entryWarning, "discovery URL is not valid", 3}},
+		},
+	}
+
+	for i, tt := range tests {
+		r := Report{}
+		n, err := parseCloudConfig([]byte(tt.config), &r)
+		if err != nil {
+			panic(err)
+		}
+		checkDiscoveryUrl(n, &r)
+
+		if e := r.Entries(); !reflect.DeepEqual(tt.entries, e) {
+			t.Errorf("bad report (%d, %q): want %#v, got %#v", i, tt.config, tt.entries, e)
+		}
+	}
+}
+
+func TestCheckEncoding(t *testing.T) {
+	tests := []struct {
+		config string
+
+		entries []Entry
+	}{
+		{},
+		{
+			config: "write_files:\n  - encoding: base64\n    content: aGVsbG8K",
+		},
+		{
+			config: "write_files:\n  - content: !!binary aGVsbG8K",
+		},
+		{
+			config:  "write_files:\n  - encoding: base64\n    content: !!binary aGVsbG8K",
+			entries: []Entry{{entryError, `content cannot be decoded as "base64"`, 3}},
+		},
+		{
+			config: "write_files:\n  - encoding: base64\n    content: !!binary YUdWc2JHOEsK",
+		},
+		{
+			config: "write_files:\n  - encoding: gzip\n    content: !!binary H4sIAOC3tVQAA8tIzcnJ5wIAIDA6NgYAAAA=",
+		},
+		{
+			config: "write_files:\n  - encoding: gzip+base64\n    content: H4sIAOC3tVQAA8tIzcnJ5wIAIDA6NgYAAAA=",
+		},
+		{
+			config:  "write_files:\n  - encoding: custom\n    content: hello",
+			entries: []Entry{{entryError, `content cannot be decoded as "custom"`, 3}},
+		},
+	}
+
+	for i, tt := range tests {
+		r := Report{}
+		n, err := parseCloudConfig([]byte(tt.config), &r)
+		if err != nil {
+			panic(err)
+		}
+		checkEncoding(n, &r)
+
+		if e := r.Entries(); !reflect.DeepEqual(tt.entries, e) {
+			t.Errorf("bad report (%d, %q): want %#v, got %#v", i, tt.config, tt.entries, e)
+		}
+	}
+}
+
+func TestCheckStructure(t *testing.T) {
+	tests := []struct {
+		config string
+
+		entries []Entry
+	}{
+		{},
+
+		// Test for unrecognized keys
+		{
+			config:  "test:",
+			entries: []Entry{{entryWarning, "unrecognized key \"test\"", 1}},
+		},
+		{
+			config:  "coreos:\n  etcd:\n    bad:",
+			entries: []Entry{{entryWarning, "unrecognized key \"bad\"", 3}},
+		},
+		{
+			config: "coreos:\n  etcd:\n    discovery: good",
+		},
+
+		// Test for deprecated keys
+		{
+			config: "coreos:\n  etcd:\n    addr: hi",
+		},
+		{
+			config:  "coreos:\n  etcd:\n    proxy: hi",
+			entries: []Entry{{entryWarning, "deprecated key \"proxy\" (etcd2 options no longer work for etcd)", 3}},
+		},
+
+		// Test for error on list of nodes
+		{
+			config: "coreos:\n  units:\n    - hello\n    - goodbye",
+			entries: []Entry{
+				{entryWarning, "incorrect type for \"units[0]\" (want struct)", 3},
+				{entryWarning, "incorrect type for \"units[1]\" (want struct)", 4},
+			},
+		},
+
+		// Test for incorrect types
+		// Want boolean
+		{
+			config: "coreos:\n  units:\n    - enable: true",
+		},
+		{
+			config:  "coreos:\n  units:\n    - enable: 4",
+			entries: []Entry{{entryWarning, "incorrect type for \"enable\" (want bool)", 3}},
+		},
+		{
+			config:  "coreos:\n  units:\n    - enable: bad",
+			entries: []Entry{{entryWarning, "incorrect type for \"enable\" (want bool)", 3}},
+		},
+		{
+			config:  "coreos:\n  units:\n    - enable:\n        bad:",
+			entries: []Entry{{entryWarning, "incorrect type for \"enable\" (want bool)", 3}},
+		},
+		{
+			config:  "coreos:\n  units:\n    - enable:\n      - bad",
+			entries: []Entry{{entryWarning, "incorrect type for \"enable\" (want bool)", 3}},
+		},
+		// Want string
+		{
+			config: "hostname: true",
+		},
+		{
+			config: "hostname: 4",
+		},
+		{
+			config: "hostname: host",
+		},
+		{
+			config:  "hostname:\n  name:",
+			entries: []Entry{{entryWarning, "incorrect type for \"hostname\" (want string)", 1}},
+		},
+		{
+			config:  "hostname:\n  - name",
+			entries: []Entry{{entryWarning, "incorrect type for \"hostname\" (want string)", 1}},
+		},
+		// Want struct
+		{
+			config:  "coreos: true",
+			entries: []Entry{{entryWarning, "incorrect type for \"coreos\" (want struct)", 1}},
+		},
+		{
+			config:  "coreos: 4",
+			entries: []Entry{{entryWarning, "incorrect type for \"coreos\" (want struct)", 1}},
+		},
+		{
+			config:  "coreos: hello",
+			entries: []Entry{{entryWarning, "incorrect type for \"coreos\" (want struct)", 1}},
+		},
+		{
+			config: "coreos:\n  etcd:\n    discovery: fire in the disco",
+		},
+		{
+			config:  "coreos:\n  - hello",
+			entries: []Entry{{entryWarning, "incorrect type for \"coreos\" (want struct)", 1}},
+		},
+		// Want []string
+		{
+			config:  "ssh_authorized_keys: true",
+			entries: []Entry{{entryWarning, "incorrect type for \"ssh_authorized_keys\" (want []string)", 1}},
+		},
+		{
+			config:  "ssh_authorized_keys: 4",
+			entries: []Entry{{entryWarning, "incorrect type for \"ssh_authorized_keys\" (want []string)", 1}},
+		},
+		{
+			config:  "ssh_authorized_keys: key",
+			entries: []Entry{{entryWarning, "incorrect type for \"ssh_authorized_keys\" (want []string)", 1}},
+		},
+		{
+			config:  "ssh_authorized_keys:\n  key: value",
+			entries: []Entry{{entryWarning, "incorrect type for \"ssh_authorized_keys\" (want []string)", 1}},
+		},
+		{
+			config: "ssh_authorized_keys:\n  - key",
+		},
+		{
+			config:  "ssh_authorized_keys:\n  - key: value",
+			entries: []Entry{{entryWarning, "incorrect type for \"ssh_authorized_keys[0]\" (want string)", 2}},
+		},
+		// Want []struct
+		{
+			config:  "users:\n  true",
+			entries: []Entry{{entryWarning, "incorrect type for \"users\" (want []struct)", 1}},
+		},
+		{
+			config:  "users:\n  4",
+			entries: []Entry{{entryWarning, "incorrect type for \"users\" (want []struct)", 1}},
+		},
+		{
+			config:  "users:\n  bad",
+			entries: []Entry{{entryWarning, "incorrect type for \"users\" (want []struct)", 1}},
+		},
+		{
+			config:  "users:\n  bad:",
+			entries: []Entry{{entryWarning, "incorrect type for \"users\" (want []struct)", 1}},
+		},
+		{
+			config: "users:\n  - name: good",
+		},
+		// Want struct within array
+		{
+			config:  "users:\n  - true",
+			entries: []Entry{{entryWarning, "incorrect type for \"users[0]\" (want struct)", 2}},
+		},
+		{
+			config:  "users:\n  - name: hi\n  - true",
+			entries: []Entry{{entryWarning, "incorrect type for \"users[1]\" (want struct)", 3}},
+		},
+		{
+			config:  "users:\n  - 4",
+			entries: []Entry{{entryWarning, "incorrect type for \"users[0]\" (want struct)", 2}},
+		},
+		{
+			config:  "users:\n  - bad",
+			entries: []Entry{{entryWarning, "incorrect type for \"users[0]\" (want struct)", 2}},
+		},
+		{
+			config:  "users:\n  - - bad",
+			entries: []Entry{{entryWarning, "incorrect type for \"users[0]\" (want struct)", 2}},
+		},
+	}
+
+	for i, tt := range tests {
+		r := Report{}
+		n, err := parseCloudConfig([]byte(tt.config), &r)
+		if err != nil {
+			panic(err)
+		}
+		checkStructure(n, &r)
+
+		if e := r.Entries(); !reflect.DeepEqual(tt.entries, e) {
+			t.Errorf("bad report (%d, %q): want %#v, got %#v", i, tt.config, tt.entries, e)
+		}
+	}
+}
+
+func TestCheckValidity(t *testing.T) {
+	tests := []struct {
+		config string
+
+		entries []Entry
+	}{
+		// string
+		{
+			config: "hostname: test",
+		},
+
+		// int
+		{
+			config: "coreos:\n  fleet:\n    verbosity: 2",
+		},
+
+		// bool
+		{
+			config: "coreos:\n  units:\n    - enable: true",
+		},
+
+		// slice
+		{
+			config: "coreos:\n  units:\n    - command: start\n    - name: stop",
+		},
+		{
+			config:  "coreos:\n  units:\n    - command: lol",
+			entries: []Entry{{entryError, "invalid value lol", 3}},
+		},
+
+		// struct
+		{
+			config: "coreos:\n  update:\n    reboot_strategy: off",
+		},
+		{
+			config:  "coreos:\n  update:\n    reboot_strategy: always",
+			entries: []Entry{{entryError, "invalid value always", 3}},
+		},
+
+		// unknown
+		{
+			config: "unknown: hi",
+		},
+	}
+
+	for i, tt := range tests {
+		r := Report{}
+		n, err := parseCloudConfig([]byte(tt.config), &r)
+		if err != nil {
+			panic(err)
+		}
+		checkValidity(n, &r)
+
+		if e := r.Entries(); !reflect.DeepEqual(tt.entries, e) {
+			t.Errorf("bad report (%d, %q): want %#v, got %#v", i, tt.config, tt.entries, e)
+		}
+	}
+}
+
+func TestCheckWriteFiles(t *testing.T) {
+	tests := []struct {
+		config string
+
+		entries []Entry
+	}{
+		{},
+		{
+			config: "write_files:\n  - path: /valid",
+		},
+		{
+			config: "write_files:\n  - path: /tmp/usr/valid",
+		},
+		{
+			config:  "write_files:\n  - path: /usr/invalid",
+			entries: []Entry{{entryError, "file cannot be written to a read-only filesystem", 2}},
+		},
+		{
+			config:  "write-files:\n  - path: /tmp/../usr/invalid",
+			entries: []Entry{{entryError, "file cannot be written to a read-only filesystem", 2}},
+		},
+	}
+
+	for i, tt := range tests {
+		r := Report{}
+		n, err := parseCloudConfig([]byte(tt.config), &r)
+		if err != nil {
+			panic(err)
+		}
+		checkWriteFiles(n, &r)
+
+		if e := r.Entries(); !reflect.DeepEqual(tt.entries, e) {
+			t.Errorf("bad report (%d, %q): want %#v, got %#v", i, tt.config, tt.entries, e)
+		}
+	}
+}
+
+func TestCheckWriteFilesUnderCoreos(t *testing.T) {
+	tests := []struct {
+		config string
+
+		entries []Entry
+	}{
+		{},
+		{
+			config: "write_files:\n  - path: /hi",
+		},
+		{
+			config:  "coreos:\n  write_files:\n    - path: /hi",
+			entries: []Entry{{entryInfo, "write_files doesn't belong under coreos", 2}},
+		},
+		{
+			config:  "coreos:\n  write-files:\n    - path: /hyphen",
+			entries: []Entry{{entryInfo, "write_files doesn't belong under coreos", 2}},
+		},
+	}
+
+	for i, tt := range tests {
+		r := Report{}
+		n, err := parseCloudConfig([]byte(tt.config), &r)
+		if err != nil {
+			panic(err)
+		}
+		checkWriteFilesUnderCoreos(n, &r)
+
+		if e := r.Entries(); !reflect.DeepEqual(tt.entries, e) {
+			t.Errorf("bad report (%d, %q): want %#v, got %#v", i, tt.config, tt.entries, e)
+		}
+	}
+}
--- a/config/validate/validate.go
+++ b/config/validate/validate.go
@@ -0,0 +1,164 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/coreos/coreos-cloudinit/config"
+
+	yaml "gopkg.in/yaml.v2"
+)
+
+var (
+	yamlLineError = regexp.MustCompile(`^YAML error: line (?P<line>[[:digit:]]+): (?P<msg>.*)$`)
+	yamlError     = regexp.MustCompile(`^YAML error: (?P<msg>.*)$`)
+)
+
+// Validate runs a series of validation tests against the given userdata and
+// returns a report detailing all of the issues. Presently, only cloud-configs
+// can be validated.
+func Validate(userdataBytes []byte) (Report, error) {
+	switch {
+	case len(userdataBytes) == 0:
+		return Report{}, nil
+	case config.IsScript(string(userdataBytes)):
+		return Report{}, nil
+	case config.IsIgnitionConfig(string(userdataBytes)):
+		return Report{}, nil
+	case config.IsCloudConfig(string(userdataBytes)):
+		return validateCloudConfig(userdataBytes, Rules)
+	default:
+		return Report{entries: []Entry{
+			Entry{kind: entryError, message: `must be "#cloud-config" or begin with "#!"`, line: 1},
+		}}, nil
+	}
+}
+
+// validateCloudConfig runs all of the validation rules in Rules and returns
+// the resulting report and any errors encountered.
+func validateCloudConfig(config []byte, rules []rule) (report Report, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("%v", r)
+		}
+	}()
+
+	c, err := parseCloudConfig(config, &report)
+	if err != nil {
+		return report, err
+	}
+
+	for _, r := range rules {
+		r(c, &report)
+	}
+	return report, nil
+}
+
+// parseCloudConfig parses the provided config into a node structure and logs
+// any parsing issues into the provided report. Unrecoverable errors are
+// returned as an error.
+func parseCloudConfig(cfg []byte, report *Report) (node, error) {
+	//	yaml.UnmarshalMappingKeyTransform = func(nameIn string) (nameOut string) {
+	//		return nameIn
+	//	}
+	// unmarshal the config into an implicitly-typed form. The yaml library
+	// will implicitly convert types into their normalized form
+	// (e.g. 0744 -> 484, off -> false).
+	var weak map[interface{}]interface{}
+	if err := yaml.Unmarshal(cfg, &weak); err != nil {
+		matches := yamlLineError.FindStringSubmatch(err.Error())
+		if len(matches) == 3 {
+			line, err := strconv.Atoi(matches[1])
+			if err != nil {
+				return node{}, err
+			}
+			msg := matches[2]
+			report.Error(line, msg)
+			return node{}, nil
+		}
+
+		matches = yamlError.FindStringSubmatch(err.Error())
+		if len(matches) == 2 {
+			report.Error(1, matches[1])
+			return node{}, nil
+		}
+
+		return node{}, errors.New("couldn't parse yaml error")
+	}
+	w := NewNode(weak, NewContext(cfg))
+	w = normalizeNodeNames(w, report)
+
+	// unmarshal the config into the explicitly-typed form.
+	//	yaml.UnmarshalMappingKeyTransform = func(nameIn string) (nameOut string) {
+	//		return strings.Replace(nameIn, "-", "_", -1)
+	//	}
+	var strong config.CloudConfig
+	if err := yaml.Unmarshal([]byte(cfg), &strong); err != nil {
+		return node{}, err
+	}
+	s := NewNode(strong, NewContext(cfg))
+
+	// coerceNodes weak nodes and strong nodes. strong nodes replace weak nodes
+	// if they are compatible types (this happens when the yaml library
+	// converts the input).
+	// (e.g. weak 484 is replaced by strong 0744, weak 4 is not replaced by
+	// strong false)
+	return coerceNodes(w, s), nil
+}
+
+// coerceNodes recursively evaluates two nodes, returning a new node containing
+// either the weak or strong node's value and its recursively processed
+// children. The strong node's value is used if the two nodes are leafs, are
+// both valid, and are compatible types (defined by isCompatible()). The weak
+// node is returned in all other cases. coerceNodes is used to counteract the
+// effects of yaml's automatic type conversion. The weak node is the one
+// resulting from unmarshalling into an empty interface{} (the type is
+// inferred). The strong node is the one resulting from unmarshalling into a
+// struct. If the two nodes are of compatible types, the yaml library correctly
+// parsed the value into the strongly typed unmarshalling. In this case, we
+// prefer the strong node because its actually the type we are expecting.
+func coerceNodes(w, s node) node {
+	n := w
+	n.children = nil
+	if len(w.children) == 0 && len(s.children) == 0 &&
+		w.IsValid() && s.IsValid() &&
+		isCompatible(w.Kind(), s.Kind()) {
+		n.Value = s.Value
+	}
+
+	for _, cw := range w.children {
+		n.children = append(n.children, coerceNodes(cw, s.Child(cw.name)))
+	}
+	return n
+}
+
+// normalizeNodeNames replaces all occurences of '-' with '_' within key names
+// and makes a note of each replacement in the report.
+func normalizeNodeNames(node node, report *Report) node {
+	if strings.Contains(node.name, "-") {
+		// TODO(crawford): Enable this message once the new validator hits stable.
+		//report.Info(node.line, fmt.Sprintf("%q uses '-' instead of '_'", node.name))
+		node.name = strings.Replace(node.name, "-", "_", -1)
+	}
+	for i := range node.children {
+		node.children[i] = normalizeNodeNames(node.children[i], report)
+	}
+	return node
+}
--- a/config/validate/validate_test.go
+++ b/config/validate/validate_test.go
@@ -0,0 +1,177 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"errors"
+	"reflect"
+	"testing"
+)
+
+func TestParseCloudConfig(t *testing.T) {
+	tests := []struct {
+		config string
+
+		entries []Entry
+	}{
+		{},
+		{
+			config: "	",
+			entries: []Entry{{entryError, "found character that cannot start any token", 1}},
+		},
+		{
+			config:  "a:\na",
+			entries: []Entry{{entryError, "could not find expected ':'", 2}},
+		},
+		{
+			config:  "#hello\na:\na",
+			entries: []Entry{{entryError, "could not find expected ':'", 3}},
+		},
+	}
+
+	for _, tt := range tests {
+		r := Report{}
+		parseCloudConfig([]byte(tt.config), &r)
+
+		if e := r.Entries(); !reflect.DeepEqual(tt.entries, e) {
+			t.Errorf("bad report (%s): want %#v, got %#v", tt.config, tt.entries, e)
+		}
+	}
+}
+
+func TestValidateCloudConfig(t *testing.T) {
+	tests := []struct {
+		config string
+		rules  []rule
+
+		report Report
+		err    error
+	}{
+		{
+			rules: []rule{func(_ node, _ *Report) { panic("something happened") }},
+			err:   errors.New("something happened"),
+		},
+		{
+			config: "write_files:\n  - permissions: 0744",
+			rules:  Rules,
+		},
+		{
+			config: "write_files:\n  - permissions: '0744'",
+			rules:  Rules,
+		},
+		{
+			config: "write_files:\n  - permissions: 744",
+			rules:  Rules,
+		},
+		{
+			config: "write_files:\n  - permissions: '744'",
+			rules:  Rules,
+		},
+		{
+			config: "coreos:\n  update:\n    reboot-strategy: off",
+			rules:  Rules,
+		},
+		{
+			config: "coreos:\n  update:\n    reboot-strategy: false",
+			rules:  Rules,
+			report: Report{entries: []Entry{{entryError, "invalid value false", 3}}},
+		},
+	}
+
+	for _, tt := range tests {
+		r, err := validateCloudConfig([]byte(tt.config), tt.rules)
+		if !reflect.DeepEqual(tt.err, err) {
+			t.Errorf("bad error (%s): want %v, got %v", tt.config, tt.err, err)
+		}
+		if !reflect.DeepEqual(tt.report, r) {
+			t.Errorf("bad report (%s): want %+v, got %+v", tt.config, tt.report, r)
+		}
+	}
+}
+
+func TestValidate(t *testing.T) {
+	tests := []struct {
+		config string
+
+		report Report
+	}{
+		{},
+		{
+			config: "#!/bin/bash\necho hey",
+		},
+		{
+			config: "{}",
+			report: Report{entries: []Entry{{entryError, `must be "#cloud-config" or begin with "#!"`, 1}}},
+		},
+		{
+			config: `{"ignitionVersion":0}`,
+		},
+		{
+			config: `{"ignitionVersion":1}`,
+		},
+	}
+
+	for i, tt := range tests {
+		r, err := Validate([]byte(tt.config))
+		if err != nil {
+			t.Errorf("bad error (case #%d): want %v, got %v", i, nil, err)
+		}
+		if !reflect.DeepEqual(tt.report, r) {
+			t.Errorf("bad report (case #%d): want %+v, got %+v", i, tt.report, r)
+		}
+	}
+}
+
+func BenchmarkValidate(b *testing.B) {
+	config := `#cloud-config
+hostname: test
+
+coreos:
+  etcd:
+    name:      node001
+    discovery: https://discovery.etcd.io/disco
+    addr:      $public_ipv4:4001
+    peer-addr: $private_ipv4:7001
+  fleet:
+    verbosity: 2
+    metadata:  "hi"
+  update:
+    reboot-strategy: off
+  units:
+    - name:    hi.service
+      command: start
+      enable:  true
+    - name:    bye.service
+      command: stop
+
+ssh_authorized_keys:
+  - ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC0g+ZTxC7weoIJLUafOgrm+h...
+  - ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC0g+ZTxC7weoIJLUafOgrm+h...
+
+users:
+  - name: me
+
+write_files:
+  - path: /etc/yes
+    content: "Hi"
+
+manage_etc_hosts: localhost`
+
+	for i := 0; i < b.N; i++ {
+		if _, err := Validate([]byte(config)); err != nil {
+			panic(err)
+		}
+	}
+}
--- a/coreos-cloudinit.go
+++ b/coreos-cloudinit.go
@@ -1,188 +1,444 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package main

 import (
-	"encoding/json"
+	"bytes"
+	"compress/gzip"
 	"flag"
 	"fmt"
 	"io/ioutil"
+	"log"
 	"os"
-	"path"
+	"runtime"
+	"sync"
+	"time"

+	"github.com/coreos/coreos-cloudinit/config"
+	"github.com/coreos/coreos-cloudinit/config/validate"
 	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/datasource/configdrive"
+	"github.com/coreos/coreos-cloudinit/datasource/file"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata/openstack"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata/digitalocean"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata/ec2"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata/packet"
+	"github.com/coreos/coreos-cloudinit/datasource/proc_cmdline"
+	"github.com/coreos/coreos-cloudinit/datasource/url"
+
+	//	"github.com/coreos/coreos-cloudinit/datasource/vmware"
+	"github.com/coreos/coreos-cloudinit/datasource/waagent"
 	"github.com/coreos/coreos-cloudinit/initialize"
 	"github.com/coreos/coreos-cloudinit/network"
+	"github.com/coreos/coreos-cloudinit/pkg"
 	"github.com/coreos/coreos-cloudinit/system"
 )

-const version = "0.7.5"
+var (
+	datasourceInterval    = 100 * time.Millisecond
+	datasourceMaxInterval = 30 * time.Second
+	datasourceTimeout     = 5 * time.Minute
+)
+
+var (
+	flags = struct {
+		printVersion  bool
+		ignoreFailure bool
+		sources       struct {
+			file               string
+			configDrive        string
+			waagent            string
+			metadataService    bool
+			ec2MetadataService string
+			openstackMetadataService string
+			//			cloudSigmaMetadataService   bool
+			digitalOceanMetadataService string
+			packetMetadataService       string
+			url                         string
+			procCmdLine                 bool
+			//			vmware                      bool
+		}
+		convertNetconf string
+		workspace      string
+		sshKeyName     string
+		oem            string
+		validate       bool
+		timeout        string
+		dstimeout      string
+	}{}
+	version = "was not built properly"
+)
+
+func init() {
+	flag.BoolVar(&flags.printVersion, "version", false, "Print the version and exit")
+	flag.BoolVar(&flags.ignoreFailure, "ignore-failure", false, "Exits with 0 status in the event of malformed input from user-data")
+	flag.StringVar(&flags.sources.file, "from-file", "", "Read user-data from provided file")
+	flag.StringVar(&flags.sources.configDrive, "from-configdrive", "", "Read data from provided cloud-drive directory")
+	flag.StringVar(&flags.sources.waagent, "from-waagent", "", "Read data from provided waagent directory")
+	flag.StringVar(&flags.sources.ec2MetadataService, "from-ec2-metadata", "", "Download EC2 data from the provided url")
+	//	flag.BoolVar(&flags.sources.cloudSigmaMetadataService, "from-cloudsigma-metadata", false, "Download data from CloudSigma server context")
+	flag.StringVar(&flags.sources.digitalOceanMetadataService, "from-digitalocean-metadata", "", "Download DigitalOcean data from the provided url")
+	flag.StringVar(&flags.sources.openstackMetadataService, "from-openstack-metadata", "", "Download OpenStack data from the provided url")
+	flag.StringVar(&flags.sources.packetMetadataService, "from-packet-metadata", "", "Download Packet data from metadata service")
+	flag.StringVar(&flags.sources.url, "from-url", "", "Download user-data from provided url")
+	flag.BoolVar(&flags.sources.procCmdLine, "from-proc-cmdline", false, fmt.Sprintf("Parse %s for '%s=<url>', using the cloud-config served by an HTTP GET to <url>", proc_cmdline.ProcCmdlineLocation, proc_cmdline.ProcCmdlineCloudConfigFlag))
+	//	flag.BoolVar(&flags.sources.vmware, "from-vmware-guestinfo", false, "Read data from VMware guestinfo")
+	flag.StringVar(&flags.oem, "oem", "", "Use the settings specific to the provided OEM")
+	flag.StringVar(&flags.convertNetconf, "convert-netconf", "", "Read the network config provided in cloud-drive and translate it from the specified format into networkd unit files")
+	flag.StringVar(&flags.workspace, "workspace", "/var/lib/cloudinit", "Base directory where cloudinit should use to store data")
+	flag.StringVar(&flags.sshKeyName, "ssh-key-name", initialize.DefaultSSHKeyName, "Add SSH keys to the system with the given name")
+	flag.BoolVar(&flags.validate, "validate", false, "[EXPERIMENTAL] Validate the user-data but do not apply it to the system")
+	flag.StringVar(&flags.timeout, "timeout", "60s", "Timeout to wait for all datasource metadata")
+	flag.StringVar(&flags.dstimeout, "dstimeout", "10s", "Timeout to wait for single datasource metadata")
+}
+
+type oemConfig map[string]string
+
+var (
+	oemConfigs = map[string]oemConfig{
+		"digitalocean": oemConfig{
+			"from-digitalocean-metadata": "http://169.254.169.254/",
+			"convert-netconf":            "digitalocean",
+		},
+		"ec2-compat": oemConfig{
+			"from-ec2-metadata": "http://169.254.169.254/",
+			"from-configdrive":  "/media/configdrive",
+		},
+		"rackspace-onmetal": oemConfig{
+			"from-configdrive": "/media/configdrive",
+			"convert-netconf":  "debian",
+		},
+		"azure": oemConfig{
+			"from-waagent": "/var/lib/waagent",
+		},
+		//		"cloudsigma": oemConfig{
+		//			"from-cloudsigma-metadata": "true",
+		//		},
+		"packet": oemConfig{
+			"from-packet-metadata": "https://metadata.packet.net/",
+		},
+		//		"vmware": oemConfig{
+		//			"from-vmware-guestinfo": "true",
+		//			"convert-netconf":       "vmware",
+		//		},
+	}
+)

 func main() {
-	var printVersion bool
-	flag.BoolVar(&printVersion, "version", false, "Print the version and exit")
+	var err error
+	failure := false

-	var ignoreFailure bool
-	flag.BoolVar(&ignoreFailure, "ignore-failure", false, "Exits with 0 status in the event of malformed input from user-data")
-
-	var file string
-	flag.StringVar(&file, "from-file", "", "Read user-data from provided file")
-
-	var configdrive string
-	flag.StringVar(&configdrive, "from-configdrive", "", "Read user-data from provided cloud-drive directory")
-
-	var url string
-	flag.StringVar(&url, "from-url", "", "Download user-data from provided url")
-
-	var useProcCmdline bool
-	flag.BoolVar(&useProcCmdline, "from-proc-cmdline", false, fmt.Sprintf("Parse %s for '%s=<url>', using the cloud-config served by an HTTP GET to <url>", datasource.ProcCmdlineLocation, datasource.ProcCmdlineCloudConfigFlag))
-
-	var convertNetconf string
-	flag.StringVar(&convertNetconf, "convert-netconf", "", "Read the network config provided in cloud-drive and translate it from the specified format into networkd unit files (requires the -from-configdrive flag)")
-
-	var workspace string
-	flag.StringVar(&workspace, "workspace", "/var/lib/coreos-cloudinit", "Base directory coreos-cloudinit should use to store data")
-
-	var sshKeyName string
-	flag.StringVar(&sshKeyName, "ssh-key-name", initialize.DefaultSSHKeyName, "Add SSH keys to the system with the given name")
+	// Conservative Go 1.5 upgrade strategy:
+	// keep GOMAXPROCS' default at 1 for now.
+	if os.Getenv("GOMAXPROCS") == "" {
+		runtime.GOMAXPROCS(1)
+	}

 	flag.Parse()

-	if printVersion == true {
-		fmt.Printf("coreos-cloudinit version %s\n", version)
+	if c, ok := oemConfigs[flags.oem]; ok {
+		for k, v := range c {
+			flag.Set(k, v)
+		}
+	} else if flags.oem != "" {
+		oems := make([]string, 0, len(oemConfigs))
+		for k := range oemConfigs {
+			oems = append(oems, k)
+		}
+		fmt.Printf("Invalid option to -oem: %q. Supported options: %q\n", flags.oem, oems)
+		os.Exit(2)
+	}
+
+	if flags.printVersion == true {
+		fmt.Printf("coreos-cloudinit %s\n", version)
 		os.Exit(0)
 	}

-	var ds datasource.Datasource
-	if file != "" {
-		ds = datasource.NewLocalFile(file)
-	} else if url != "" {
-		ds = datasource.NewMetadataService(url)
-	} else if configdrive != "" {
-		ds = datasource.NewConfigDrive(configdrive)
-	} else if useProcCmdline {
-		ds = datasource.NewProcCmdline()
-	} else {
-		fmt.Println("Provide one of --from-file, --from-configdrive, --from-url or --from-proc-cmdline")
+	datasourceTimeout, err = time.ParseDuration(flags.timeout)
+	if err != nil {
+		fmt.Printf("Invalid value to --timeout: %q\n", err)
+		os.Exit(1)
+	}
+	datasourceMaxInterval, err = time.ParseDuration(flags.dstimeout)
+	if err != nil {
+		fmt.Printf("Invalid value to --dstimeout: %q\n", err)
 		os.Exit(1)
 	}

-	if convertNetconf != "" && configdrive == "" {
-		fmt.Println("-convert-netconf flag requires -from-configdrive")
-		os.Exit(1)
-	}
-
-	switch convertNetconf {
+	switch flags.convertNetconf {
 	case "":
 	case "debian":
+	case "digitalocean":
+	case "packet":
+		//	case "vmware":
 	default:
-		fmt.Printf("Invalid option to -convert-netconf: '%s'. Supported options: 'debian'\n", convertNetconf)
+		fmt.Printf("Invalid option to -convert-netconf: '%s'. Supported options: 'debian, digitalocean, packet, vmware'\n", flags.convertNetconf)
+		os.Exit(2)
+	}
+
+	dss := getDatasources()
+	if len(dss) == 0 {
+		fmt.Println("Provide at least one of --from-file, --from-configdrive, --from-openstack-metadata, --from-ec2-metadata, --from-cloudsigma-metadata, --from-packet-metadata, --from-digitalocean-metadata, --from-vmware-guestinfo, --from-waagent, --from-url or --from-proc-cmdline")
+		os.Exit(2)
+	}
+  fmt.Printf("%#+v\n", dss)
+	ds := selectDatasource(dss)
+	if ds == nil {
+		log.Println("No datasources available in time")
 		os.Exit(1)
 	}

-	fmt.Printf("Fetching user-data from datasource of type %q\n", ds.Type())
-	userdataBytes, err := ds.Fetch()
+	log.Printf("Fetching user-data from datasource of type %q\n", ds.Type())
+	userdataBytes, err := ds.FetchUserdata()
 	if err != nil {
-		fmt.Printf("Failed fetching user-data from datasource: %v\n", err)
-		if ignoreFailure {
-			os.Exit(0)
-		} else {
+		log.Printf("Failed fetching user-data from datasource: %v. Continuing...\n", err)
+		failure = true
+	}
+	userdataBytes, err = decompressIfGzip(userdataBytes)
+	if err != nil {
+		log.Printf("Failed decompressing user-data from datasource: %v. Continuing...\n", err)
+		failure = true
+	}
+
+	if report, err := validate.Validate(userdataBytes); err == nil {
+		ret := 0
+		for _, e := range report.Entries() {
+			log.Println(e)
+			ret = 1
+		}
+		if flags.validate {
+			os.Exit(ret)
+		}
+	} else {
+		log.Printf("Failed while validating user_data (%q)\n", err)
+		if flags.validate {
 			os.Exit(1)
 		}
 	}

-	env := initialize.NewEnvironment("/", workspace)
-	if len(userdataBytes) > 0 {
-		if err := processUserdata(string(userdataBytes), env); err != nil {
-			fmt.Printf("Failed resolving user-data: %v\n", err)
-			if !ignoreFailure {
-				os.Exit(1)
-			}
-		}
-	} else {
-		fmt.Println("No user data to handle.")
+	log.Printf("Fetching meta-data from datasource of type %q\n", ds.Type())
+	metadata, err := ds.FetchMetadata()
+	if err != nil {
+		log.Printf("Failed fetching meta-data from datasource: %v\n", err)
+		os.Exit(1)
 	}

-	if convertNetconf != "" {
-		if err := processNetconf(convertNetconf, configdrive); err != nil {
-			fmt.Printf("Failed to process network config: %v\n", err)
-			if !ignoreFailure {
-				os.Exit(1)
-			}
+	// Apply environment to user-data
+	env := initialize.NewEnvironment("/", ds.ConfigRoot(), flags.workspace, flags.sshKeyName, metadata)
+	userdata := env.Apply(string(userdataBytes))
+
+	var ccu *config.CloudConfig
+	var script *config.Script
+	switch ud, err := initialize.ParseUserData(userdata); err {
+	case initialize.ErrIgnitionConfig:
+		fmt.Printf("Detected an Ignition config. Exiting...")
+		os.Exit(0)
+	case nil:
+		switch t := ud.(type) {
+		case *config.CloudConfig:
+			ccu = t
+		case *config.Script:
+			script = t
 		}
+	default:
+		fmt.Printf("Failed to parse user-data: %v\nContinuing...\n", err)
+		failure = true
+	}
+
+	log.Println("Merging cloud-config from meta-data and user-data")
+	cc := mergeConfigs(ccu, metadata)
+
+	var ifaces []network.InterfaceGenerator
+	if flags.convertNetconf != "" {
+		var err error
+		switch flags.convertNetconf {
+		case "debian":
+			ifaces, err = network.ProcessDebianNetconf(metadata.NetworkConfig.([]byte))
+		case "digitalocean":
+			ifaces, err = network.ProcessDigitalOceanNetconf(metadata.NetworkConfig.(digitalocean.Metadata))
+		case "packet":
+			ifaces, err = network.ProcessPacketNetconf(metadata.NetworkConfig.(packet.NetworkData))
+			//		case "vmware":
+			//			ifaces, err = network.ProcessVMwareNetconf(metadata.NetworkConfig.(map[string]string))
+		default:
+			err = fmt.Errorf("Unsupported network config format %q", flags.convertNetconf)
+		}
+		if err != nil {
+			log.Printf("Failed to generate interfaces: %v\n", err)
+			os.Exit(1)
+		}
+	}
+
+	if err = initialize.Apply(cc, ifaces, env); err != nil {
+		log.Printf("Failed to apply cloud-config: %v\n", err)
+		os.Exit(1)
+	}
+
+	if script != nil {
+		if err = runScript(*script, env); err != nil {
+			log.Printf("Failed to run script: %v\n", err)
+			os.Exit(1)
+		}
+	}
+
+	if failure && !flags.ignoreFailure {
+		os.Exit(1)
 	}
 }

-func processUserdata(userdata string, env *initialize.Environment) error {
-	userdata = env.Apply(userdata)
-
-	parsed, err := initialize.ParseUserData(userdata)
-	if err != nil {
-		fmt.Printf("Failed parsing user-data: %v\n", err)
-		return err
+// mergeConfigs merges certain options from md (meta-data from the datasource)
+// onto cc (a CloudConfig derived from user-data), if they are not already set
+// on cc (i.e. user-data always takes precedence)
+func mergeConfigs(cc *config.CloudConfig, md datasource.Metadata) (out config.CloudConfig) {
+	if cc != nil {
+		out = *cc
 	}

-	err = initialize.PrepWorkspace(env.Workspace())
-	if err != nil {
-		fmt.Printf("Failed preparing workspace: %v\n", err)
-		return err
-	}
-
-	switch t := parsed.(type) {
-	case initialize.CloudConfig:
-		err = initialize.Apply(t, env)
-	case system.Script:
-		var path string
-		path, err = initialize.PersistScriptInWorkspace(t, env.Workspace())
-		if err == nil {
-			var name string
-			name, err = system.ExecuteScript(path)
-			initialize.PersistUnitNameInWorkspace(name, env.Workspace())
+	if md.Hostname != "" {
+		if out.Hostname != "" {
+			log.Printf("Warning: user-data hostname (%s) overrides metadata hostname (%s)\n", out.Hostname, md.Hostname)
+		} else {
+			out.Hostname = md.Hostname
 		}
 	}
+	for _, key := range md.SSHPublicKeys {
+		out.SSHAuthorizedKeys = append(out.SSHAuthorizedKeys, key)
+	}
+	return
+}

+// getDatasources creates a slice of possible Datasources for cloudinit based
+// on the different source command-line flags.
+func getDatasources() []datasource.Datasource {
+	dss := make([]datasource.Datasource, 0, 5)
+	if flags.sources.file != "" {
+		dss = append(dss, file.NewDatasource(flags.sources.file))
+	}
+	if flags.sources.url != "" {
+		dss = append(dss, url.NewDatasource(flags.sources.url))
+	}
+	if flags.sources.configDrive != "" {
+		dss = append(dss, configdrive.NewDatasource(flags.sources.configDrive))
+	}
+	if flags.sources.metadataService {
+		dss = append(dss, ec2.NewDatasource(ec2.DefaultAddress))
+	}
+	if flags.sources.openstackMetadataService != "" {
+	  dss = append(dss, openstack.NewDatasource(flags.sources.openstackMetadataService))
+  }
+	if flags.sources.ec2MetadataService != "" {
+		dss = append(dss, ec2.NewDatasource(flags.sources.ec2MetadataService))
+	}
+	//	if flags.sources.cloudSigmaMetadataService {
+	//		dss = append(dss, cloudsigma.NewServerContextService())
+	//	}
+	if flags.sources.digitalOceanMetadataService != "" {
+		dss = append(dss, digitalocean.NewDatasource(flags.sources.digitalOceanMetadataService))
+	}
+	if flags.sources.waagent != "" {
+		dss = append(dss, waagent.NewDatasource(flags.sources.waagent))
+	}
+	if flags.sources.packetMetadataService != "" {
+		dss = append(dss, packet.NewDatasource(flags.sources.packetMetadataService))
+	}
+	if flags.sources.procCmdLine {
+		dss = append(dss, proc_cmdline.NewDatasource())
+	}
+	//	if flags.sources.vmware {
+	//		dss = append(dss, vmware.NewDatasource())
+	//	}
+	return dss
+}
+
+// selectDatasource attempts to choose a valid Datasource to use based on its
+// current availability. The first Datasource to report to be available is
+// returned. Datasources will be retried if possible if they are not
+// immediately available. If all Datasources are permanently unavailable or
+// datasourceTimeout is reached before one becomes available, nil is returned.
+func selectDatasource(sources []datasource.Datasource) datasource.Datasource {
+	ds := make(chan datasource.Datasource)
+	stop := make(chan struct{})
+	var wg sync.WaitGroup
+
+	for _, s := range sources {
+		wg.Add(1)
+		go func(s datasource.Datasource) {
+			defer wg.Done()
+
+			duration := datasourceInterval
+			for {
+				log.Printf("Checking availability of %q\n", s.Type())
+				if s.IsAvailable() {
+					ds <- s
+					return
+				} else if !s.AvailabilityChanges() {
+					return
+				}
+				select {
+				case <-stop:
+					return
+				case <-time.After(duration):
+					duration = pkg.ExpBackoff(duration, datasourceMaxInterval)
+				}
+			}
+		}(s)
+	}
+
+	done := make(chan struct{})
+	go func() {
+		wg.Wait()
+		close(done)
+	}()
+
+	var s datasource.Datasource
+	select {
+	case s = <-ds:
+	case <-done:
+	case <-time.After(datasourceTimeout):
+	}
+
+	close(stop)
+	return s
+}
+
+// TODO(jonboulle): this should probably be refactored and moved into a different module
+func runScript(script config.Script, env *initialize.Environment) error {
+	err := initialize.PrepWorkspace(env.Workspace())
+	if err != nil {
+		log.Printf("Failed preparing workspace: %v\n", err)
+		return err
+	}
+	path, err := initialize.PersistScriptInWorkspace(script, env.Workspace())
+	if err == nil {
+		var name string
+		name, err = system.ExecuteScript(path)
+		initialize.PersistUnitNameInWorkspace(name, env.Workspace())
+	}
 	return err
 }

-func processNetconf(convertNetconf, configdrive string) error {
-	openstackRoot := path.Join(configdrive, "openstack")
-	metadataFilename := path.Join(openstackRoot, "latest", "meta_data.json")
-	metadataBytes, err := ioutil.ReadFile(metadataFilename)
+const gzipMagicBytes = "\x1f\x8b"
+
+func decompressIfGzip(userdataBytes []byte) ([]byte, error) {
+	if !bytes.HasPrefix(userdataBytes, []byte(gzipMagicBytes)) {
+		return userdataBytes, nil
+	}
+	gzr, err := gzip.NewReader(bytes.NewReader(userdataBytes))
 	if err != nil {
-		return err
+		return nil, err
 	}
-
-	var metadata struct {
-		NetworkConfig struct {
-			ContentPath string `json:"content_path"`
-		} `json:"network_config"`
-	}
-	if err := json.Unmarshal(metadataBytes, &metadata); err != nil {
-		return err
-	}
-	configPath := metadata.NetworkConfig.ContentPath
-	if configPath == "" {
-		fmt.Printf("No network config specified in %q.\n", metadataFilename)
-		return nil
-	}
-
-	netconfBytes, err := ioutil.ReadFile(path.Join(openstackRoot, configPath))
-	if err != nil {
-		return err
-	}
-
-	var interfaces []network.InterfaceGenerator
-	switch convertNetconf {
-	case "debian":
-		interfaces, err = network.ProcessDebianNetconf(string(netconfBytes))
-	default:
-		return fmt.Errorf("Unsupported network config format %q", convertNetconf)
-	}
-
-	if err != nil {
-		return err
-	}
-
-	if err := system.WriteNetworkdConfigs(interfaces); err != nil {
-		return err
-	}
-	return system.RestartNetwork(interfaces)
+	defer gzr.Close()
+	return ioutil.ReadAll(gzr)
 }
--- a/coreos-cloudinit_test.go
+++ b/coreos-cloudinit_test.go
@@ -0,0 +1,147 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"bytes"
+	"encoding/base64"
+	"errors"
+	"reflect"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/config"
+	"github.com/coreos/coreos-cloudinit/datasource"
+)
+
+func TestMergeConfigs(t *testing.T) {
+	tests := []struct {
+		cc *config.CloudConfig
+		md datasource.Metadata
+
+		out config.CloudConfig
+	}{
+		{
+			// If md is empty and cc is nil, result should be empty
+			out: config.CloudConfig{},
+		},
+		{
+			// If md and cc are empty, result should be empty
+			cc:  &config.CloudConfig{},
+			out: config.CloudConfig{},
+		},
+		{
+			// If cc is empty, cc should be returned unchanged
+			cc:  &config.CloudConfig{SSHAuthorizedKeys: []string{"abc", "def"}, Hostname: "cc-host"},
+			out: config.CloudConfig{SSHAuthorizedKeys: []string{"abc", "def"}, Hostname: "cc-host"},
+		},
+		{
+			// If cc is empty, cc should be returned unchanged(overridden)
+			cc:  &config.CloudConfig{},
+			md:  datasource.Metadata{Hostname: "md-host", SSHPublicKeys: map[string]string{"key": "ghi"}},
+			out: config.CloudConfig{SSHAuthorizedKeys: []string{"ghi"}, Hostname: "md-host"},
+		},
+		{
+			// If cc is nil, cc should be returned unchanged(overridden)
+			md:  datasource.Metadata{Hostname: "md-host", SSHPublicKeys: map[string]string{"key": "ghi"}},
+			out: config.CloudConfig{SSHAuthorizedKeys: []string{"ghi"}, Hostname: "md-host"},
+		},
+		{
+			// user-data should override completely in the case of conflicts
+			cc:  &config.CloudConfig{SSHAuthorizedKeys: []string{"abc", "def"}, Hostname: "cc-host"},
+			md:  datasource.Metadata{Hostname: "md-host"},
+			out: config.CloudConfig{SSHAuthorizedKeys: []string{"abc", "def"}, Hostname: "cc-host"},
+		},
+		{
+			// Mixed merge should succeed
+			cc:  &config.CloudConfig{SSHAuthorizedKeys: []string{"abc", "def"}, Hostname: "cc-host"},
+			md:  datasource.Metadata{Hostname: "md-host", SSHPublicKeys: map[string]string{"key": "ghi"}},
+			out: config.CloudConfig{SSHAuthorizedKeys: []string{"abc", "def", "ghi"}, Hostname: "cc-host"},
+		},
+		{
+			// Completely non-conflicting merge should be fine
+			cc:  &config.CloudConfig{Hostname: "cc-host"},
+			md:  datasource.Metadata{SSHPublicKeys: map[string]string{"zaphod": "beeblebrox"}},
+			out: config.CloudConfig{Hostname: "cc-host", SSHAuthorizedKeys: []string{"beeblebrox"}},
+		},
+		{
+			// Non-mergeable settings in user-data should not be affected
+			cc:  &config.CloudConfig{Hostname: "cc-host", ManageEtcHosts: config.EtcHosts("lolz")},
+			md:  datasource.Metadata{Hostname: "md-host"},
+			out: config.CloudConfig{Hostname: "cc-host", ManageEtcHosts: config.EtcHosts("lolz")},
+		},
+	}
+
+	for i, tt := range tests {
+		out := mergeConfigs(tt.cc, tt.md)
+		if !reflect.DeepEqual(tt.out, out) {
+			t.Errorf("bad config (%d): want %#v, got %#v", i, tt.out, out)
+		}
+	}
+}
+
+func mustDecode(in string) []byte {
+	out, err := base64.StdEncoding.DecodeString(in)
+	if err != nil {
+		panic(err)
+	}
+	return out
+}
+
+func TestDecompressIfGzip(t *testing.T) {
+	tests := []struct {
+		in []byte
+
+		out []byte
+		err error
+	}{
+		{
+			in: nil,
+
+			out: nil,
+			err: nil,
+		},
+		{
+			in: []byte{},
+
+			out: []byte{},
+			err: nil,
+		},
+		{
+			in: mustDecode("H4sIAJWV/VUAA1NOzskvTdFNzs9Ly0wHABt6mQENAAAA"),
+
+			out: []byte("#cloud-config"),
+			err: nil,
+		},
+		{
+			in: []byte("#cloud-config"),
+
+			out: []byte("#cloud-config"),
+			err: nil,
+		},
+		{
+			in: mustDecode("H4sCORRUPT=="),
+
+			out: nil,
+			err: errors.New("any error"),
+		},
+	}
+	for i, tt := range tests {
+		out, err := decompressIfGzip(tt.in)
+		if !bytes.Equal(out, tt.out) || (tt.err != nil && err == nil) {
+			t.Errorf("bad gzip (%d): want (%s, %#v), got (%s, %#v)", i, string(tt.out), tt.err, string(out), err)
+		}
+	}
+
+}
--- a/datasource/configdrive.go
+++ b/datasource/configdrive.go
@@ -1,27 +0,0 @@
-package datasource
-
-import (
-	"io/ioutil"
-	"os"
-	"path"
-)
-
-type configDrive struct {
-	path string
-}
-
-func NewConfigDrive(path string) *configDrive {
-	return &configDrive{path}
-}
-
-func (self *configDrive) Fetch() ([]byte, error) {
-	data, err := ioutil.ReadFile(path.Join(self.path, "openstack", "latest", "user_data"))
-	if os.IsNotExist(err) {
-		err = nil
-	}
-	return data, err
-}
-
-func (self *configDrive) Type() string {
-	return "cloud-drive"
-}
--- a/datasource/configdrive/configdrive.go
+++ b/datasource/configdrive/configdrive.go
@@ -0,0 +1,102 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package configdrive
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"os"
+	"path"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+)
+
+const (
+	openstackApiVersion = "latest"
+)
+
+type configDrive struct {
+	root     string
+	readFile func(filename string) ([]byte, error)
+}
+
+func NewDatasource(root string) *configDrive {
+	return &configDrive{root, ioutil.ReadFile}
+}
+
+func (cd *configDrive) IsAvailable() bool {
+	_, err := os.Stat(cd.root)
+	return !os.IsNotExist(err)
+}
+
+func (cd *configDrive) AvailabilityChanges() bool {
+	return true
+}
+
+func (cd *configDrive) ConfigRoot() string {
+	return cd.openstackRoot()
+}
+
+func (cd *configDrive) FetchMetadata() (metadata datasource.Metadata, err error) {
+	var data []byte
+	var m struct {
+		SSHAuthorizedKeyMap map[string]string `json:"public_keys"`
+		Hostname            string            `json:"hostname"`
+		NetworkConfig       struct {
+			ContentPath string `json:"content_path"`
+		} `json:"network_config"`
+	}
+
+	if data, err = cd.tryReadFile(path.Join(cd.openstackVersionRoot(), "meta_data.json")); err != nil || len(data) == 0 {
+		return
+	}
+	if err = json.Unmarshal([]byte(data), &m); err != nil {
+		return
+	}
+
+	metadata.SSHPublicKeys = m.SSHAuthorizedKeyMap
+	metadata.Hostname = m.Hostname
+	if m.NetworkConfig.ContentPath != "" {
+		metadata.NetworkConfig, err = cd.tryReadFile(path.Join(cd.openstackRoot(), m.NetworkConfig.ContentPath))
+	}
+
+	return
+}
+
+func (cd *configDrive) FetchUserdata() ([]byte, error) {
+	return cd.tryReadFile(path.Join(cd.openstackVersionRoot(), "user_data"))
+}
+
+func (cd *configDrive) Type() string {
+	return "cloud-drive"
+}
+
+func (cd *configDrive) openstackRoot() string {
+	return path.Join(cd.root, "openstack")
+}
+
+func (cd *configDrive) openstackVersionRoot() string {
+	return path.Join(cd.openstackRoot(), openstackApiVersion)
+}
+
+func (cd *configDrive) tryReadFile(filename string) ([]byte, error) {
+	log.Printf("Attempting to read from %q\n", filename)
+	data, err := cd.readFile(filename)
+	if os.IsNotExist(err) {
+		err = nil
+	}
+	return data, err
+}
--- a/datasource/configdrive/configdrive_test.go
+++ b/datasource/configdrive/configdrive_test.go
@@ -0,0 +1,145 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package configdrive
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/datasource/test"
+)
+
+func TestFetchMetadata(t *testing.T) {
+	for _, tt := range []struct {
+		root  string
+		files test.MockFilesystem
+
+		metadata datasource.Metadata
+	}{
+		{
+			root:  "/",
+			files: test.NewMockFilesystem(test.File{Path: "/openstack/latest/meta_data.json", Contents: ""}),
+		},
+		{
+			root:  "/",
+			files: test.NewMockFilesystem(test.File{Path: "/openstack/latest/meta_data.json", Contents: `{"ignore": "me"}`}),
+		},
+		{
+			root:     "/",
+			files:    test.NewMockFilesystem(test.File{Path: "/openstack/latest/meta_data.json", Contents: `{"hostname": "host"}`}),
+			metadata: datasource.Metadata{Hostname: "host"},
+		},
+		{
+			root: "/media/configdrive",
+			files: test.NewMockFilesystem(test.File{Path: "/media/configdrive/openstack/latest/meta_data.json", Contents: `{"hostname": "host", "network_config": {"content_path": "config_file.json"}, "public_keys":{"1": "key1", "2": "key2"}}`},
+				test.File{Path: "/media/configdrive/openstack/config_file.json", Contents: "make it work"},
+			),
+			metadata: datasource.Metadata{
+				Hostname:      "host",
+				NetworkConfig: []byte("make it work"),
+				SSHPublicKeys: map[string]string{
+					"1": "key1",
+					"2": "key2",
+				},
+			},
+		},
+	} {
+		cd := configDrive{tt.root, tt.files.ReadFile}
+		metadata, err := cd.FetchMetadata()
+		if err != nil {
+			t.Fatalf("bad error for %+v: want %v, got %q", tt, nil, err)
+		}
+		if !reflect.DeepEqual(tt.metadata, metadata) {
+			t.Fatalf("bad metadata for %+v: want %#v, got %#v", tt, tt.metadata, metadata)
+		}
+	}
+}
+
+func TestFetchUserdata(t *testing.T) {
+	for _, tt := range []struct {
+		root  string
+		files test.MockFilesystem
+
+		userdata string
+	}{
+		{
+			"/",
+			test.NewMockFilesystem(),
+			"",
+		},
+		{
+			"/",
+			test.NewMockFilesystem(test.File{Path: "/openstack/latest/user_data", Contents: "userdata"}),
+			"userdata",
+		},
+		{
+			"/media/configdrive",
+			test.NewMockFilesystem(test.File{Path: "/media/configdrive/openstack/latest/user_data", Contents: "userdata"}),
+			"userdata",
+		},
+	} {
+		cd := configDrive{tt.root, tt.files.ReadFile}
+		userdata, err := cd.FetchUserdata()
+		if err != nil {
+			t.Fatalf("bad error for %+v: want %v, got %q", tt, nil, err)
+		}
+		if string(userdata) != tt.userdata {
+			t.Fatalf("bad userdata for %+v: want %q, got %q", tt, tt.userdata, userdata)
+		}
+	}
+}
+
+func TestConfigRoot(t *testing.T) {
+	for _, tt := range []struct {
+		root       string
+		configRoot string
+	}{
+		{
+			"/",
+			"/openstack",
+		},
+		{
+			"/media/configdrive",
+			"/media/configdrive/openstack",
+		},
+	} {
+		cd := configDrive{tt.root, nil}
+		if configRoot := cd.ConfigRoot(); configRoot != tt.configRoot {
+			t.Fatalf("bad config root for %q: want %q, got %q", tt, tt.configRoot, configRoot)
+		}
+	}
+}
+
+func TestNewDatasource(t *testing.T) {
+	for _, tt := range []struct {
+		root       string
+		expectRoot string
+	}{
+		{
+			root:       "",
+			expectRoot: "",
+		},
+		{
+			root:       "/media/configdrive",
+			expectRoot: "/media/configdrive",
+		},
+	} {
+		service := NewDatasource(tt.root)
+		if service.root != tt.expectRoot {
+			t.Fatalf("bad root (%q): want %q, got %q", tt.root, tt.expectRoot, service.root)
+		}
+	}
+}
--- a/datasource/datasource.go
+++ b/datasource/datasource.go
@@ -1,6 +1,38 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package datasource

+import (
+	"net"
+)
+
 type Datasource interface {
-	Fetch() ([]byte, error)
+	IsAvailable() bool
+	AvailabilityChanges() bool
+	ConfigRoot() string
+	FetchMetadata() (Metadata, error)
+	FetchUserdata() ([]byte, error)
 	Type() string
 }
+
+type Metadata struct {
+	PublicIPv4    net.IP
+	PublicIPv6    net.IP
+	PrivateIPv4   net.IP
+	PrivateIPv6   net.IP
+	Hostname      string
+	SSHPublicKeys map[string]string
+	NetworkConfig interface{}
+}
--- a/datasource/file.go
+++ b/datasource/file.go
@@ -1,21 +0,0 @@
-package datasource
-
-import (
-	"io/ioutil"
-)
-
-type localFile struct {
-	path string
-}
-
-func NewLocalFile(path string) *localFile {
-	return &localFile{path}
-}
-
-func (self *localFile) Fetch() ([]byte, error) {
-	return ioutil.ReadFile(self.path)
-}
-
-func (self *localFile) Type() string {
-	return "local-file"
-}
--- a/datasource/file/file.go
+++ b/datasource/file/file.go
@@ -0,0 +1,55 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package file
+
+import (
+	"io/ioutil"
+	"os"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+)
+
+type localFile struct {
+	path string
+}
+
+func NewDatasource(path string) *localFile {
+	return &localFile{path}
+}
+
+func (f *localFile) IsAvailable() bool {
+	_, err := os.Stat(f.path)
+	return !os.IsNotExist(err)
+}
+
+func (f *localFile) AvailabilityChanges() bool {
+	return true
+}
+
+func (f *localFile) ConfigRoot() string {
+	return ""
+}
+
+func (f *localFile) FetchMetadata() (datasource.Metadata, error) {
+	return datasource.Metadata{}, nil
+}
+
+func (f *localFile) FetchUserdata() ([]byte, error) {
+	return ioutil.ReadFile(f.path)
+}
+
+func (f *localFile) Type() string {
+	return "local-file"
+}
--- a/datasource/metadata/digitalocean/metadata.go
+++ b/datasource/metadata/digitalocean/metadata.go
@@ -0,0 +1,111 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package digitalocean
+
+import (
+	"encoding/json"
+	"net"
+	"strconv"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata"
+)
+
+const (
+	DefaultAddress = "http://169.254.169.254/"
+	apiVersion     = "metadata/v1"
+	userdataUrl    = apiVersion + "/user-data"
+	metadataPath   = apiVersion + ".json"
+)
+
+type Address struct {
+	IPAddress string `json:"ip_address"`
+	Netmask   string `json:"netmask"`
+	Cidr      int    `json:"cidr"`
+	Gateway   string `json:"gateway"`
+}
+
+type Interface struct {
+	IPv4       *Address `json:"ipv4"`
+	IPv6       *Address `json:"ipv6"`
+	AnchorIPv4 *Address `json:"anchor_ipv4"`
+	MAC        string   `json:"mac"`
+	Type       string   `json:"type"`
+}
+
+type Interfaces struct {
+	Public  []Interface `json:"public"`
+	Private []Interface `json:"private"`
+}
+
+type DNS struct {
+	Nameservers []string `json:"nameservers"`
+}
+
+type Metadata struct {
+	Hostname   string     `json:"hostname"`
+	Interfaces Interfaces `json:"interfaces"`
+	PublicKeys []string   `json:"public_keys"`
+	DNS        DNS        `json:"dns"`
+}
+
+type metadataService struct {
+	metadata.MetadataService
+}
+
+func NewDatasource(root string) *metadataService {
+	return &metadataService{MetadataService: metadata.NewDatasource(root, apiVersion, userdataUrl, metadataPath)}
+}
+
+func (ms *metadataService) FetchMetadata() (metadata datasource.Metadata, err error) {
+	var data []byte
+	var m Metadata
+
+	if data, err = ms.FetchData(ms.MetadataUrl()); err != nil || len(data) == 0 {
+		return
+	}
+	if err = json.Unmarshal(data, &m); err != nil {
+		return
+	}
+
+	if len(m.Interfaces.Public) > 0 {
+		if m.Interfaces.Public[0].IPv4 != nil {
+			metadata.PublicIPv4 = net.ParseIP(m.Interfaces.Public[0].IPv4.IPAddress)
+		}
+		if m.Interfaces.Public[0].IPv6 != nil {
+			metadata.PublicIPv6 = net.ParseIP(m.Interfaces.Public[0].IPv6.IPAddress)
+		}
+	}
+	if len(m.Interfaces.Private) > 0 {
+		if m.Interfaces.Private[0].IPv4 != nil {
+			metadata.PrivateIPv4 = net.ParseIP(m.Interfaces.Private[0].IPv4.IPAddress)
+		}
+		if m.Interfaces.Private[0].IPv6 != nil {
+			metadata.PrivateIPv6 = net.ParseIP(m.Interfaces.Private[0].IPv6.IPAddress)
+		}
+	}
+	metadata.Hostname = m.Hostname
+	metadata.SSHPublicKeys = map[string]string{}
+	for i, key := range m.PublicKeys {
+		metadata.SSHPublicKeys[strconv.Itoa(i)] = key
+	}
+	metadata.NetworkConfig = m
+
+	return
+}
+
+func (ms metadataService) Type() string {
+	return "digitalocean-metadata-service"
+}
--- a/datasource/metadata/digitalocean/metadata_test.go
+++ b/datasource/metadata/digitalocean/metadata_test.go
@@ -0,0 +1,143 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package digitalocean
+
+import (
+	"fmt"
+	"net"
+	"reflect"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata/test"
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
+
+func TestType(t *testing.T) {
+	want := "digitalocean-metadata-service"
+	if kind := (metadataService{}).Type(); kind != want {
+		t.Fatalf("bad type: want %q, got %q", want, kind)
+	}
+}
+
+func TestFetchMetadata(t *testing.T) {
+	for _, tt := range []struct {
+		root         string
+		metadataPath string
+		resources    map[string]string
+		expect       datasource.Metadata
+		clientErr    error
+		expectErr    error
+	}{
+		{
+			root:         "/",
+			metadataPath: "v1.json",
+			resources: map[string]string{
+				"/v1.json": "bad",
+			},
+			expectErr: fmt.Errorf("invalid character 'b' looking for beginning of value"),
+		},
+		{
+			root:         "/",
+			metadataPath: "v1.json",
+			resources: map[string]string{
+				"/v1.json": `{
+  "droplet_id": 1,
+  "user_data": "hello",
+  "vendor_data": "hello",
+  "public_keys": [
+    "publickey1",
+    "publickey2"
+  ],
+  "region": "nyc2",
+  "interfaces": {
+    "public": [
+      {
+        "ipv4": {
+          "ip_address": "192.168.1.2",
+          "netmask": "255.255.255.0",
+          "gateway": "192.168.1.1"
+        },
+        "ipv6": {
+          "ip_address": "fe00::",
+          "cidr": 126,
+          "gateway": "fe00::"
+        },
+        "mac": "ab:cd:ef:gh:ij",
+        "type": "public"
+      }
+    ]
+  }
+}`,
+			},
+			expect: datasource.Metadata{
+				PublicIPv4: net.ParseIP("192.168.1.2"),
+				PublicIPv6: net.ParseIP("fe00::"),
+				SSHPublicKeys: map[string]string{
+					"0": "publickey1",
+					"1": "publickey2",
+				},
+				NetworkConfig: Metadata{
+					Interfaces: Interfaces{
+						Public: []Interface{
+							Interface{
+								IPv4: &Address{
+									IPAddress: "192.168.1.2",
+									Netmask:   "255.255.255.0",
+									Gateway:   "192.168.1.1",
+								},
+								IPv6: &Address{
+									IPAddress: "fe00::",
+									Cidr:      126,
+									Gateway:   "fe00::",
+								},
+								MAC:  "ab:cd:ef:gh:ij",
+								Type: "public",
+							},
+						},
+					},
+					PublicKeys: []string{"publickey1", "publickey2"},
+				},
+			},
+		},
+		{
+			clientErr: pkg.ErrTimeout{Err: fmt.Errorf("test error")},
+			expectErr: pkg.ErrTimeout{Err: fmt.Errorf("test error")},
+		},
+	} {
+		service := &metadataService{
+			MetadataService: metadata.MetadataService{
+				Root:         tt.root,
+				Client:       &test.HttpClient{Resources: tt.resources, Err: tt.clientErr},
+				MetadataPath: tt.metadataPath,
+			},
+		}
+		metadata, err := service.FetchMetadata()
+		if Error(err) != Error(tt.expectErr) {
+			t.Fatalf("bad error (%q): want %q, got %q", tt.resources, tt.expectErr, err)
+		}
+		if !reflect.DeepEqual(tt.expect, metadata) {
+			t.Fatalf("bad fetch (%q): want %#q, got %#q", tt.resources, tt.expect, metadata)
+		}
+	}
+}
+
+func Error(err error) string {
+	if err != nil {
+		return err.Error()
+	}
+	return ""
+}
--- a/datasource/metadata/ec2/metadata.go
+++ b/datasource/metadata/ec2/metadata.go
@@ -0,0 +1,115 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ec2
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"log"
+	"net"
+	"strings"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata"
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
+
+const (
+	DefaultAddress = "http://169.254.169.254/"
+	apiVersion     = "2009-04-04/"
+	userdataPath   = apiVersion + "user-data"
+	metadataPath   = apiVersion + "meta-data"
+)
+
+type metadataService struct {
+	metadata.MetadataService
+}
+
+func NewDatasource(root string) *metadataService {
+	return &metadataService{metadata.NewDatasource(root, apiVersion, userdataPath, metadataPath)}
+}
+
+func (ms metadataService) FetchMetadata() (datasource.Metadata, error) {
+	metadata := datasource.Metadata{}
+
+	if keynames, err := ms.fetchAttributes(fmt.Sprintf("%s/public-keys", ms.MetadataUrl())); err == nil {
+		keyIDs := make(map[string]string)
+		for _, keyname := range keynames {
+			tokens := strings.SplitN(keyname, "=", 2)
+			if len(tokens) != 2 {
+				return metadata, fmt.Errorf("malformed public key: %q", keyname)
+			}
+			keyIDs[tokens[1]] = tokens[0]
+		}
+
+		metadata.SSHPublicKeys = map[string]string{}
+		for name, id := range keyIDs {
+			sshkey, err := ms.fetchAttribute(fmt.Sprintf("%s/public-keys/%s/openssh-key", ms.MetadataUrl(), id))
+			if err != nil {
+				return metadata, err
+			}
+			metadata.SSHPublicKeys[name] = sshkey
+			log.Printf("Found SSH key for %q\n", name)
+		}
+	} else if _, ok := err.(pkg.ErrNotFound); !ok {
+		return metadata, err
+	}
+
+	if hostname, err := ms.fetchAttribute(fmt.Sprintf("%s/hostname", ms.MetadataUrl())); err == nil {
+		metadata.Hostname = strings.Split(hostname, " ")[0]
+	} else if _, ok := err.(pkg.ErrNotFound); !ok {
+		return metadata, err
+	}
+
+	if localAddr, err := ms.fetchAttribute(fmt.Sprintf("%s/local-ipv4", ms.MetadataUrl())); err == nil {
+		metadata.PrivateIPv4 = net.ParseIP(localAddr)
+	} else if _, ok := err.(pkg.ErrNotFound); !ok {
+		return metadata, err
+	}
+
+	if publicAddr, err := ms.fetchAttribute(fmt.Sprintf("%s/public-ipv4", ms.MetadataUrl())); err == nil {
+		metadata.PublicIPv4 = net.ParseIP(publicAddr)
+	} else if _, ok := err.(pkg.ErrNotFound); !ok {
+		return metadata, err
+	}
+
+	return metadata, nil
+}
+
+func (ms metadataService) Type() string {
+	return "ec2-metadata-service"
+}
+
+func (ms metadataService) fetchAttributes(url string) ([]string, error) {
+	resp, err := ms.FetchData(url)
+	if err != nil {
+		return nil, err
+	}
+	scanner := bufio.NewScanner(bytes.NewBuffer(resp))
+	data := make([]string, 0)
+	for scanner.Scan() {
+		data = append(data, scanner.Text())
+	}
+	return data, scanner.Err()
+}
+
+func (ms metadataService) fetchAttribute(url string) (string, error) {
+	if attrs, err := ms.fetchAttributes(url); err == nil && len(attrs) > 0 {
+		return attrs[0], nil
+	} else {
+		return "", err
+	}
+}
--- a/datasource/metadata/ec2/metadata_test.go
+++ b/datasource/metadata/ec2/metadata_test.go
@@ -0,0 +1,222 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ec2
+
+import (
+	"fmt"
+	"net"
+	"reflect"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata/test"
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
+
+func TestType(t *testing.T) {
+	want := "ec2-metadata-service"
+	if kind := (metadataService{}).Type(); kind != want {
+		t.Fatalf("bad type: want %q, got %q", want, kind)
+	}
+}
+
+func TestFetchAttributes(t *testing.T) {
+	for _, s := range []struct {
+		resources map[string]string
+		err       error
+		tests     []struct {
+			path string
+			val  []string
+		}
+	}{
+		{
+			resources: map[string]string{
+				"/":      "a\nb\nc/",
+				"/c/":    "d\ne/",
+				"/c/e/":  "f",
+				"/a":     "1",
+				"/b":     "2",
+				"/c/d":   "3",
+				"/c/e/f": "4",
+			},
+			tests: []struct {
+				path string
+				val  []string
+			}{
+				{"/", []string{"a", "b", "c/"}},
+				{"/b", []string{"2"}},
+				{"/c/d", []string{"3"}},
+				{"/c/e/", []string{"f"}},
+			},
+		},
+		{
+			err: fmt.Errorf("test error"),
+			tests: []struct {
+				path string
+				val  []string
+			}{
+				{"", nil},
+			},
+		},
+	} {
+		service := metadataService{metadata.MetadataService{
+			Client: &test.HttpClient{Resources: s.resources, Err: s.err},
+		}}
+		for _, tt := range s.tests {
+			attrs, err := service.fetchAttributes(tt.path)
+			if err != s.err {
+				t.Fatalf("bad error for %q (%q): want %q, got %q", tt.path, s.resources, s.err, err)
+			}
+			if !reflect.DeepEqual(attrs, tt.val) {
+				t.Fatalf("bad fetch for %q (%q): want %q, got %q", tt.path, s.resources, tt.val, attrs)
+			}
+		}
+	}
+}
+
+func TestFetchAttribute(t *testing.T) {
+	for _, s := range []struct {
+		resources map[string]string
+		err       error
+		tests     []struct {
+			path string
+			val  string
+		}
+	}{
+		{
+			resources: map[string]string{
+				"/":      "a\nb\nc/",
+				"/c/":    "d\ne/",
+				"/c/e/":  "f",
+				"/a":     "1",
+				"/b":     "2",
+				"/c/d":   "3",
+				"/c/e/f": "4",
+			},
+			tests: []struct {
+				path string
+				val  string
+			}{
+				{"/a", "1"},
+				{"/b", "2"},
+				{"/c/d", "3"},
+				{"/c/e/f", "4"},
+			},
+		},
+		{
+			err: fmt.Errorf("test error"),
+			tests: []struct {
+				path string
+				val  string
+			}{
+				{"", ""},
+			},
+		},
+	} {
+		service := metadataService{metadata.MetadataService{
+			Client: &test.HttpClient{Resources: s.resources, Err: s.err},
+		}}
+		for _, tt := range s.tests {
+			attr, err := service.fetchAttribute(tt.path)
+			if err != s.err {
+				t.Fatalf("bad error for %q (%q): want %q, got %q", tt.path, s.resources, s.err, err)
+			}
+			if attr != tt.val {
+				t.Fatalf("bad fetch for %q (%q): want %q, got %q", tt.path, s.resources, tt.val, attr)
+			}
+		}
+	}
+}
+
+func TestFetchMetadata(t *testing.T) {
+	for _, tt := range []struct {
+		root         string
+		metadataPath string
+		resources    map[string]string
+		expect       datasource.Metadata
+		clientErr    error
+		expectErr    error
+	}{
+		{
+			root:         "/",
+			metadataPath: "2009-04-04/meta-data",
+			resources: map[string]string{
+				"/2009-04-04/meta-data/public-keys": "bad\n",
+			},
+			expectErr: fmt.Errorf("malformed public key: \"bad\""),
+		},
+		{
+			root:         "/",
+			metadataPath: "2009-04-04/meta-data",
+			resources: map[string]string{
+				"/2009-04-04/meta-data/hostname":                  "host",
+				"/2009-04-04/meta-data/local-ipv4":                "1.2.3.4",
+				"/2009-04-04/meta-data/public-ipv4":               "5.6.7.8",
+				"/2009-04-04/meta-data/public-keys":               "0=test1\n",
+				"/2009-04-04/meta-data/public-keys/0":             "openssh-key",
+				"/2009-04-04/meta-data/public-keys/0/openssh-key": "key",
+			},
+			expect: datasource.Metadata{
+				Hostname:      "host",
+				PrivateIPv4:   net.ParseIP("1.2.3.4"),
+				PublicIPv4:    net.ParseIP("5.6.7.8"),
+				SSHPublicKeys: map[string]string{"test1": "key"},
+			},
+		},
+		{
+			root:         "/",
+			metadataPath: "2009-04-04/meta-data",
+			resources: map[string]string{
+				"/2009-04-04/meta-data/hostname":                  "host domain another_domain",
+				"/2009-04-04/meta-data/local-ipv4":                "1.2.3.4",
+				"/2009-04-04/meta-data/public-ipv4":               "5.6.7.8",
+				"/2009-04-04/meta-data/public-keys":               "0=test1\n",
+				"/2009-04-04/meta-data/public-keys/0":             "openssh-key",
+				"/2009-04-04/meta-data/public-keys/0/openssh-key": "key",
+			},
+			expect: datasource.Metadata{
+				Hostname:      "host",
+				PrivateIPv4:   net.ParseIP("1.2.3.4"),
+				PublicIPv4:    net.ParseIP("5.6.7.8"),
+				SSHPublicKeys: map[string]string{"test1": "key"},
+			},
+		},
+		{
+			clientErr: pkg.ErrTimeout{Err: fmt.Errorf("test error")},
+			expectErr: pkg.ErrTimeout{Err: fmt.Errorf("test error")},
+		},
+	} {
+		service := &metadataService{metadata.MetadataService{
+			Root:         tt.root,
+			Client:       &test.HttpClient{Resources: tt.resources, Err: tt.clientErr},
+			MetadataPath: tt.metadataPath,
+		}}
+		metadata, err := service.FetchMetadata()
+		if Error(err) != Error(tt.expectErr) {
+			t.Fatalf("bad error (%q): want %q, got %q", tt.resources, tt.expectErr, err)
+		}
+		if !reflect.DeepEqual(tt.expect, metadata) {
+			t.Fatalf("bad fetch (%q): want %#v, got %#v", tt.resources, tt.expect, metadata)
+		}
+	}
+}
+
+func Error(err error) string {
+	if err != nil {
+		return err.Error()
+	}
+	return ""
+}
--- a/datasource/metadata/metadata.go
+++ b/datasource/metadata/metadata.go
@@ -0,0 +1,71 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metadata
+
+import (
+	"strings"
+
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
+
+type MetadataService struct {
+	Root         string
+	Client       pkg.Getter
+	ApiVersion   string
+	UserdataPath string
+	MetadataPath string
+}
+
+func NewDatasource(root, apiVersion, userdataPath, metadataPath string) MetadataService {
+	if !strings.HasSuffix(root, "/") {
+		root += "/"
+	}
+	return MetadataService{root, pkg.NewHttpClient(), apiVersion, userdataPath, metadataPath}
+}
+
+func (ms MetadataService) IsAvailable() bool {
+	_, err := ms.Client.Get(ms.Root + ms.ApiVersion)
+	return (err == nil)
+}
+
+func (ms MetadataService) AvailabilityChanges() bool {
+	return true
+}
+
+func (ms MetadataService) ConfigRoot() string {
+	return ms.Root
+}
+
+func (ms MetadataService) FetchUserdata() ([]byte, error) {
+	return ms.FetchData(ms.UserdataUrl())
+}
+
+func (ms MetadataService) FetchData(url string) ([]byte, error) {
+	if data, err := ms.Client.GetRetry(url); err == nil {
+		return data, err
+	} else if _, ok := err.(pkg.ErrNotFound); ok {
+		return []byte{}, nil
+	} else {
+		return data, err
+	}
+}
+
+func (ms MetadataService) MetadataUrl() string {
+	return (ms.Root + ms.MetadataPath)
+}
+
+func (ms MetadataService) UserdataUrl() string {
+	return (ms.Root + ms.UserdataPath)
+}
--- a/datasource/metadata/metadata_test.go
+++ b/datasource/metadata/metadata_test.go
@@ -0,0 +1,185 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metadata
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/datasource/metadata/test"
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
+
+func TestAvailabilityChanges(t *testing.T) {
+	want := true
+	if ac := (MetadataService{}).AvailabilityChanges(); ac != want {
+		t.Fatalf("bad AvailabilityChanges: want %t, got %t", want, ac)
+	}
+}
+
+func TestIsAvailable(t *testing.T) {
+	for _, tt := range []struct {
+		root       string
+		apiVersion string
+		resources  map[string]string
+		expect     bool
+	}{
+		{
+			root:       "/",
+			apiVersion: "2009-04-04",
+			resources: map[string]string{
+				"/2009-04-04": "",
+			},
+			expect: true,
+		},
+		{
+			root:      "/",
+			resources: map[string]string{},
+			expect:    false,
+		},
+	} {
+		service := &MetadataService{
+			Root:       tt.root,
+			Client:     &test.HttpClient{Resources: tt.resources, Err: nil},
+			ApiVersion: tt.apiVersion,
+		}
+		if a := service.IsAvailable(); a != tt.expect {
+			t.Fatalf("bad isAvailable (%q): want %t, got %t", tt.resources, tt.expect, a)
+		}
+	}
+}
+
+func TestFetchUserdata(t *testing.T) {
+	for _, tt := range []struct {
+		root         string
+		userdataPath string
+		resources    map[string]string
+		userdata     []byte
+		clientErr    error
+		expectErr    error
+	}{
+		{
+			root:         "/",
+			userdataPath: "2009-04-04/user-data",
+			resources: map[string]string{
+				"/2009-04-04/user-data": "hello",
+			},
+			userdata: []byte("hello"),
+		},
+		{
+			root:      "/",
+			clientErr: pkg.ErrNotFound{Err: fmt.Errorf("test not found error")},
+			userdata:  []byte{},
+		},
+		{
+			root:      "/",
+			clientErr: pkg.ErrTimeout{Err: fmt.Errorf("test timeout error")},
+			expectErr: pkg.ErrTimeout{Err: fmt.Errorf("test timeout error")},
+		},
+	} {
+		service := &MetadataService{
+			Root:         tt.root,
+			Client:       &test.HttpClient{Resources: tt.resources, Err: tt.clientErr},
+			UserdataPath: tt.userdataPath,
+		}
+		data, err := service.FetchUserdata()
+		if Error(err) != Error(tt.expectErr) {
+			t.Fatalf("bad error (%q): want %q, got %q", tt.resources, tt.expectErr, err)
+		}
+		if !bytes.Equal(data, tt.userdata) {
+			t.Fatalf("bad userdata (%q): want %q, got %q", tt.resources, tt.userdata, data)
+		}
+	}
+}
+
+func TestUrls(t *testing.T) {
+	for _, tt := range []struct {
+		root         string
+		userdataPath string
+		metadataPath string
+		expectRoot   string
+		userdata     string
+		metadata     string
+	}{
+		{
+			root:         "/",
+			userdataPath: "2009-04-04/user-data",
+			metadataPath: "2009-04-04/meta-data",
+			expectRoot:   "/",
+			userdata:     "/2009-04-04/user-data",
+			metadata:     "/2009-04-04/meta-data",
+		},
+		{
+			root:         "http://169.254.169.254/",
+			userdataPath: "2009-04-04/user-data",
+			metadataPath: "2009-04-04/meta-data",
+			expectRoot:   "http://169.254.169.254/",
+			userdata:     "http://169.254.169.254/2009-04-04/user-data",
+			metadata:     "http://169.254.169.254/2009-04-04/meta-data",
+		},
+	} {
+		service := &MetadataService{
+			Root:         tt.root,
+			UserdataPath: tt.userdataPath,
+			MetadataPath: tt.metadataPath,
+		}
+		if url := service.UserdataUrl(); url != tt.userdata {
+			t.Fatalf("bad url (%q): want %q, got %q", tt.root, tt.userdata, url)
+		}
+		if url := service.MetadataUrl(); url != tt.metadata {
+			t.Fatalf("bad url (%q): want %q, got %q", tt.root, tt.metadata, url)
+		}
+		if url := service.ConfigRoot(); url != tt.expectRoot {
+			t.Fatalf("bad url (%q): want %q, got %q", tt.root, tt.expectRoot, url)
+		}
+	}
+}
+
+func TestNewDatasource(t *testing.T) {
+	for _, tt := range []struct {
+		root       string
+		expectRoot string
+	}{
+		{
+			root:       "",
+			expectRoot: "/",
+		},
+		{
+			root:       "/",
+			expectRoot: "/",
+		},
+		{
+			root:       "http://169.254.169.254",
+			expectRoot: "http://169.254.169.254/",
+		},
+		{
+			root:       "http://169.254.169.254/",
+			expectRoot: "http://169.254.169.254/",
+		},
+	} {
+		service := NewDatasource(tt.root, "", "", "")
+		if service.Root != tt.expectRoot {
+			t.Fatalf("bad root (%q): want %q, got %q", tt.root, tt.expectRoot, service.Root)
+		}
+	}
+}
+
+func Error(err error) string {
+	if err != nil {
+		return err.Error()
+	}
+	return ""
+}
--- a/datasource/metadata/openstack/metadata.go
+++ b/datasource/metadata/openstack/metadata.go
@@ -0,0 +1,112 @@
+/*
+   Copyright 2014 CoreOS, Inc.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package openstack
+
+import (
+	"encoding/json"
+	"net"
+	"strconv"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata"
+)
+
+const (
+	DefaultAddress = "http://169.254.169.254/"
+	apiVersion     = "openstack/latest"
+	userdataUrl    = apiVersion + "/user_data"
+	metadataPath   = apiVersion + "/meta_data.json"
+)
+
+type Address struct {
+	IPAddress string `json:"ip_address"`
+	Netmask   string `json:"netmask"`
+	Cidr      int    `json:"cidr"`
+	Gateway   string `json:"gateway"`
+}
+
+type Interface struct {
+	IPv4 *Address `json:"ipv4"`
+	IPv6 *Address `json:"ipv6"`
+	MAC  string   `json:"mac"`
+	Type string   `json:"type"`
+}
+
+type Interfaces struct {
+	Public  []Interface `json:"public"`
+	Private []Interface `json:"private"`
+}
+
+type DNS struct {
+	Nameservers []string `json:"nameservers"`
+}
+
+type Metadata struct {
+	Hostname   string            `json:"hostname"`
+	Interfaces Interfaces        `json:"interfaces"`
+	PublicKeys map[string]string `json:"public_keys"`
+	DNS        DNS               `json:"dns"`
+}
+
+type metadataService struct {
+	metadata.MetadataService
+}
+
+func NewDatasource(root string) *metadataService {
+	return &metadataService{MetadataService: metadata.NewDatasource(root, apiVersion, userdataUrl, metadataPath)}
+}
+
+func (ms *metadataService) FetchMetadata() (metadata datasource.Metadata, err error) {
+	var data []byte
+	var m Metadata
+
+	if data, err = ms.FetchData(ms.MetadataUrl()); err != nil || len(data) == 0 {
+		return
+	}
+
+	if err = json.Unmarshal(data, &m); err != nil {
+		return
+	}
+
+	if len(m.Interfaces.Public) > 0 {
+		if m.Interfaces.Public[0].IPv4 != nil {
+			metadata.PublicIPv4 = net.ParseIP(m.Interfaces.Public[0].IPv4.IPAddress)
+		}
+		if m.Interfaces.Public[0].IPv6 != nil {
+			metadata.PublicIPv6 = net.ParseIP(m.Interfaces.Public[0].IPv6.IPAddress)
+		}
+	}
+	if len(m.Interfaces.Private) > 0 {
+		if m.Interfaces.Private[0].IPv4 != nil {
+			metadata.PrivateIPv4 = net.ParseIP(m.Interfaces.Private[0].IPv4.IPAddress)
+		}
+		if m.Interfaces.Private[0].IPv6 != nil {
+			metadata.PrivateIPv6 = net.ParseIP(m.Interfaces.Private[0].IPv6.IPAddress)
+		}
+	}
+
+	metadata.Hostname = m.Hostname
+	metadata.SSHPublicKeys = map[string]string{}
+	metadata.SSHPublicKeys[strconv.Itoa(0)] = m.PublicKeys["root"]
+	metadata.NetworkConfig = data
+
+	return
+}
+
+func (ms metadataService) Type() string {
+	return "openstack-metadata-service"
+}
--- a/datasource/metadata/openstack/metadata_test.go
+++ b/datasource/metadata/openstack/metadata_test.go
@@ -0,0 +1,115 @@
+/*
+   Copyright 2014 CoreOS, Inc.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package openstack
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/datasource/metadata"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata/test"
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
+
+func TestType(t *testing.T) {
+	want := "openstack-metadata-service"
+	if kind := (metadataService{}).Type(); kind != want {
+		t.Fatalf("bad type: want %q, got %q", want, kind)
+	}
+}
+
+func TestFetchMetadata(t *testing.T) {
+	for _, tt := range []struct {
+		root         string
+		metadataPath string
+		resources    map[string]string
+		expect       []byte
+		clientErr    error
+		expectErr    error
+	}{
+		{
+			root:         "/",
+			metadataPath: "v1.json",
+			resources: map[string]string{
+				"/v1.json": "bad",
+			},
+			expectErr: fmt.Errorf("invalid character 'b' looking for beginning of value"),
+		},
+		{
+			root:         "/",
+			metadataPath: "v1.json",
+			resources: map[string]string{
+				"/v1.json": `{
+  "droplet_id": 1,
+  "user_data": "hello",
+  "vendor_data": "hello",
+  "public_keys": [
+    "publickey1",
+    "publickey2"
+  ],
+  "region": "nyc2",
+  "interfaces": {
+    "public": [
+      {
+        "ipv4": {
+          "ip_address": "192.168.1.2",
+          "netmask": "255.255.255.0",
+          "gateway": "192.168.1.1"
+        },
+        "ipv6": {
+          "ip_address": "fe00::",
+          "cidr": 126,
+          "gateway": "fe00::"
+        },
+        "mac": "ab:cd:ef:gh:ij",
+        "type": "public"
+      }
+    ]
+  }
+}`,
+			},
+			expect: []byte(`{"hostname":"","public-ipv4":"192.168.1.2","public-ipv6":"fe00::","public_keys":{"0":"publickey1","1":"publickey2"}}`),
+		},
+		{
+			clientErr: pkg.ErrTimeout{Err: fmt.Errorf("test error")},
+			expectErr: pkg.ErrTimeout{Err: fmt.Errorf("test error")},
+		},
+	} {
+		service := &metadataService{
+			MetadataService: metadata.MetadataService{
+				Root:         tt.root,
+				Client:       &test.HttpClient{Resources: tt.resources, Err: tt.clientErr},
+				MetadataPath: tt.metadataPath,
+			},
+		}
+		metadata, err := service.FetchMetadata()
+		if Error(err) != Error(tt.expectErr) {
+			t.Fatalf("bad error (%q): want %q, got %q", tt.resources, tt.expectErr, err)
+		}
+		if !bytes.Equal(metadata, tt.expect) {
+			t.Fatalf("bad fetch (%q): want %q, got %q", tt.resources, tt.expect, metadata)
+		}
+	}
+}
+
+func Error(err error) string {
+	if err != nil {
+		return err.Error()
+	}
+	return ""
+}
--- a/datasource/metadata/packet/metadata.go
+++ b/datasource/metadata/packet/metadata.go
@@ -0,0 +1,106 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package packet
+
+import (
+	"encoding/json"
+	"net"
+	"strconv"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/datasource/metadata"
+)
+
+const (
+	DefaultAddress = "https://metadata.packet.net/"
+	apiVersion     = ""
+	userdataUrl    = "userdata"
+	metadataPath   = "metadata"
+)
+
+type Netblock struct {
+	Address       net.IP `json:"address"`
+	Cidr          int    `json:"cidr"`
+	Netmask       net.IP `json:"netmask"`
+	Gateway       net.IP `json:"gateway"`
+	AddressFamily int    `json:"address_family"`
+	Public        bool   `json:"public"`
+}
+
+type Nic struct {
+	Name string `json:"name"`
+	Mac  string `json:"mac"`
+}
+
+type NetworkData struct {
+	Interfaces []Nic      `json:"interfaces"`
+	Netblocks  []Netblock `json:"addresses"`
+	DNS        []net.IP   `json:"dns"`
+}
+
+// Metadata that will be pulled from the https://metadata.packet.net/metadata only. We have the opportunity to add more later.
+type Metadata struct {
+	Hostname    string      `json:"hostname"`
+	SSHKeys     []string    `json:"ssh_keys"`
+	NetworkData NetworkData `json:"network"`
+}
+
+type metadataService struct {
+	metadata.MetadataService
+}
+
+func NewDatasource(root string) *metadataService {
+	return &metadataService{MetadataService: metadata.NewDatasource(root, apiVersion, userdataUrl, metadataPath)}
+}
+
+func (ms *metadataService) FetchMetadata() (metadata datasource.Metadata, err error) {
+	var data []byte
+	var m Metadata
+
+	if data, err = ms.FetchData(ms.MetadataUrl()); err != nil || len(data) == 0 {
+		return
+	}
+
+	if err = json.Unmarshal(data, &m); err != nil {
+		return
+	}
+
+	if len(m.NetworkData.Netblocks) > 0 {
+		for _, Netblock := range m.NetworkData.Netblocks {
+			if Netblock.AddressFamily == 4 {
+				if Netblock.Public == true {
+					metadata.PublicIPv4 = Netblock.Address
+				} else {
+					metadata.PrivateIPv4 = Netblock.Address
+				}
+			} else {
+				metadata.PublicIPv6 = Netblock.Address
+			}
+		}
+	}
+	metadata.Hostname = m.Hostname
+	metadata.SSHPublicKeys = map[string]string{}
+	for i, key := range m.SSHKeys {
+		metadata.SSHPublicKeys[strconv.Itoa(i)] = key
+	}
+
+	metadata.NetworkConfig = m.NetworkData
+
+	return
+}
+
+func (ms metadataService) Type() string {
+	return "packet-metadata-service"
+}
--- a/datasource/metadata/test/test.go
+++ b/datasource/metadata/test/test.go
@@ -0,0 +1,41 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package test
+
+import (
+	"fmt"
+
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
+
+type HttpClient struct {
+	Resources map[string]string
+	Err       error
+}
+
+func (t *HttpClient) GetRetry(url string) ([]byte, error) {
+	if t.Err != nil {
+		return nil, t.Err
+	}
+	if val, ok := t.Resources[url]; ok {
+		return []byte(val), nil
+	} else {
+		return nil, pkg.ErrNotFound{fmt.Errorf("not found: %q", url)}
+	}
+}
+
+func (t *HttpClient) Get(url string) ([]byte, error) {
+	return t.GetRetry(url)
+}
--- a/datasource/metadata_service.go
+++ b/datasource/metadata_service.go
@@ -1,20 +0,0 @@
-package datasource
-
-import "github.com/coreos/coreos-cloudinit/pkg"
-
-type metadataService struct {
-	url string
-}
-
-func NewMetadataService(url string) *metadataService {
-	return &metadataService{url}
-}
-
-func (ms *metadataService) Fetch() ([]byte, error) {
-	client := pkg.NewHttpClient()
-	return client.Get(ms.url)
-}
-
-func (ms *metadataService) Type() string {
-	return "metadata-service"
-}
--- a/datasource/proc_cmdline.go
+++ b/datasource/proc_cmdline.go
@@ -1,72 +0,0 @@
-package datasource
-
-import (
-	"errors"
-	"io/ioutil"
-	"log"
-	"strings"
-
-	"github.com/coreos/coreos-cloudinit/pkg"
-)
-
-const (
-	ProcCmdlineLocation        = "/proc/cmdline"
-	ProcCmdlineCloudConfigFlag = "cloud-config-url"
-)
-
-type procCmdline struct{
-	Location string
-}
-
-func NewProcCmdline() *procCmdline {
-	return &procCmdline{Location: ProcCmdlineLocation}
-}
-
-func (self *procCmdline) Fetch() ([]byte, error) {
-	contents, err := ioutil.ReadFile(self.Location)
-	if err != nil {
-		return nil, err
-	}
-
-	cmdline := strings.TrimSpace(string(contents))
-	url, err := findCloudConfigURL(cmdline)
-	if err != nil {
-		return nil, err
-	}
-
-	client := pkg.NewHttpClient()
-	cfg, err := client.Get(url)
-	if err != nil {
-		return nil, err
-	}
-
-	return cfg, nil
-}
-
-func (self *procCmdline) Type() string {
-	return "proc-cmdline"
-}
-
-func findCloudConfigURL(input string) (url string, err error) {
-	err = errors.New("cloud-config-url not found")
-	for _, token := range strings.Split(input, " ") {
-		parts := strings.SplitN(token, "=", 2)
-
-		key := parts[0]
-		key = strings.Replace(key, "_", "-", -1)
-
-		if key != "cloud-config-url" {
-			continue
-		}
-
-		if len(parts) != 2 {
-			log.Printf("Found cloud-config-url in /proc/cmdline with no value, ignoring.")
-			continue
-		}
-
-		url = parts[1]
-		err = nil
-	}
-
-	return
-}
--- a/datasource/proc_cmdline/proc_cmdline.go
+++ b/datasource/proc_cmdline/proc_cmdline.go
@@ -0,0 +1,110 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package proc_cmdline
+
+import (
+	"errors"
+	"io/ioutil"
+	"log"
+	"strings"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
+
+const (
+	ProcCmdlineLocation        = "/proc/cmdline"
+	ProcCmdlineCloudConfigFlag = "cloud-config-url"
+)
+
+type procCmdline struct {
+	Location string
+}
+
+func NewDatasource() *procCmdline {
+	return &procCmdline{Location: ProcCmdlineLocation}
+}
+
+func (c *procCmdline) IsAvailable() bool {
+	contents, err := ioutil.ReadFile(c.Location)
+	if err != nil {
+		return false
+	}
+
+	cmdline := strings.TrimSpace(string(contents))
+	_, err = findCloudConfigURL(cmdline)
+	return (err == nil)
+}
+
+func (c *procCmdline) AvailabilityChanges() bool {
+	return false
+}
+
+func (c *procCmdline) ConfigRoot() string {
+	return ""
+}
+
+func (c *procCmdline) FetchMetadata() (datasource.Metadata, error) {
+	return datasource.Metadata{}, nil
+}
+
+func (c *procCmdline) FetchUserdata() ([]byte, error) {
+	contents, err := ioutil.ReadFile(c.Location)
+	if err != nil {
+		return nil, err
+	}
+
+	cmdline := strings.TrimSpace(string(contents))
+	url, err := findCloudConfigURL(cmdline)
+	if err != nil {
+		return nil, err
+	}
+
+	client := pkg.NewHttpClient()
+	cfg, err := client.GetRetry(url)
+	if err != nil {
+		return nil, err
+	}
+
+	return cfg, nil
+}
+
+func (c *procCmdline) Type() string {
+	return "proc-cmdline"
+}
+
+func findCloudConfigURL(input string) (url string, err error) {
+	err = errors.New("cloud-config-url not found")
+	for _, token := range strings.Split(input, " ") {
+		parts := strings.SplitN(token, "=", 2)
+
+		key := parts[0]
+		key = strings.Replace(key, "_", "-", -1)
+
+		if key != "cloud-config-url" {
+			continue
+		}
+
+		if len(parts) != 2 {
+			log.Printf("Found cloud-config-url in /proc/cmdline with no value, ignoring.")
+			continue
+		}
+
+		url = parts[1]
+		err = nil
+	}
+
+	return
+}
--- a/datasource/proc_cmdline/proc_cmdline_test.go
+++ b/datasource/proc_cmdline/proc_cmdline_test.go
@@ -1,4 +1,18 @@
-package datasource
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package proc_cmdline

 import (
 	"fmt"
@@ -75,9 +89,9 @@ func TestProcCmdlineAndFetchConfig(t *testing.T) {
 		t.Errorf("Test produced error: %v", err)
 	}

-	p := NewProcCmdline()
+	p := NewDatasource()
 	p.Location = file.Name()
-	cfg, err := p.Fetch()
+	cfg, err := p.FetchUserdata()
 	if err != nil {
 		t.Errorf("Test produced error: %v", err)
 	}
--- a/datasource/test/filesystem.go
+++ b/datasource/test/filesystem.go
@@ -0,0 +1,57 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package test
+
+import (
+	"fmt"
+	"os"
+	"path"
+)
+
+type MockFilesystem map[string]File
+
+type File struct {
+	Path      string
+	Contents  string
+	Directory bool
+}
+
+func (m MockFilesystem) ReadFile(filename string) ([]byte, error) {
+	if f, ok := m[path.Clean(filename)]; ok {
+		if f.Directory {
+			return nil, fmt.Errorf("read %s: is a directory", filename)
+		}
+		return []byte(f.Contents), nil
+	}
+	return nil, os.ErrNotExist
+}
+
+func NewMockFilesystem(files ...File) MockFilesystem {
+	fs := MockFilesystem{}
+	for _, file := range files {
+		fs[file.Path] = file
+
+		// Create the directories leading up to the file
+		p := path.Dir(file.Path)
+		for p != "/" && p != "." {
+			if f, ok := fs[p]; ok && !f.Directory {
+				panic(fmt.Sprintf("%q already exists and is not a directory (%#v)", p, f))
+			}
+			fs[p] = File{Path: p, Directory: true}
+			p = path.Dir(p)
+		}
+	}
+	return fs
+}
--- a/datasource/test/filesystem_test.go
+++ b/datasource/test/filesystem_test.go
@@ -0,0 +1,115 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package test
+
+import (
+	"errors"
+	"os"
+	"reflect"
+	"testing"
+)
+
+func TestReadFile(t *testing.T) {
+	tests := []struct {
+		filesystem MockFilesystem
+
+		filename string
+		contents string
+		err      error
+	}{
+		{
+			filename: "dne",
+			err:      os.ErrNotExist,
+		},
+		{
+			filesystem: MockFilesystem{
+				"exists": File{Contents: "hi"},
+			},
+			filename: "exists",
+			contents: "hi",
+		},
+		{
+			filesystem: MockFilesystem{
+				"dir": File{Directory: true},
+			},
+			filename: "dir",
+			err:      errors.New("read dir: is a directory"),
+		},
+	}
+
+	for i, tt := range tests {
+		contents, err := tt.filesystem.ReadFile(tt.filename)
+		if tt.contents != string(contents) {
+			t.Errorf("bad contents (test %d): want %q, got %q", i, tt.contents, string(contents))
+		}
+		if !reflect.DeepEqual(tt.err, err) {
+			t.Errorf("bad error (test %d): want %v, got %v", i, tt.err, err)
+		}
+	}
+}
+
+func TestNewMockFilesystem(t *testing.T) {
+	tests := []struct {
+		files []File
+
+		filesystem MockFilesystem
+	}{
+		{
+			filesystem: MockFilesystem{},
+		},
+		{
+			files: []File{File{Path: "file"}},
+			filesystem: MockFilesystem{
+				"file": File{Path: "file"},
+			},
+		},
+		{
+			files: []File{File{Path: "/file"}},
+			filesystem: MockFilesystem{
+				"/file": File{Path: "/file"},
+			},
+		},
+		{
+			files: []File{File{Path: "/dir/file"}},
+			filesystem: MockFilesystem{
+				"/dir":      File{Path: "/dir", Directory: true},
+				"/dir/file": File{Path: "/dir/file"},
+			},
+		},
+		{
+			files: []File{File{Path: "/dir/dir/file"}},
+			filesystem: MockFilesystem{
+				"/dir":          File{Path: "/dir", Directory: true},
+				"/dir/dir":      File{Path: "/dir/dir", Directory: true},
+				"/dir/dir/file": File{Path: "/dir/dir/file"},
+			},
+		},
+		{
+			files: []File{File{Path: "/dir/dir/dir", Directory: true}},
+			filesystem: MockFilesystem{
+				"/dir":         File{Path: "/dir", Directory: true},
+				"/dir/dir":     File{Path: "/dir/dir", Directory: true},
+				"/dir/dir/dir": File{Path: "/dir/dir/dir", Directory: true},
+			},
+		},
+	}
+
+	for i, tt := range tests {
+		filesystem := NewMockFilesystem(tt.files...)
+		if !reflect.DeepEqual(tt.filesystem, filesystem) {
+			t.Errorf("bad filesystem (test %d): want %#v, got %#v", i, tt.filesystem, filesystem)
+		}
+	}
+}
--- a/datasource/url/url.go
+++ b/datasource/url/url.go
@@ -0,0 +1,55 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package url
+
+import (
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
+
+type remoteFile struct {
+	url string
+}
+
+func NewDatasource(url string) *remoteFile {
+	return &remoteFile{url}
+}
+
+func (f *remoteFile) IsAvailable() bool {
+	client := pkg.NewHttpClient()
+	_, err := client.Get(f.url)
+	return (err == nil)
+}
+
+func (f *remoteFile) AvailabilityChanges() bool {
+	return true
+}
+
+func (f *remoteFile) ConfigRoot() string {
+	return ""
+}
+
+func (f *remoteFile) FetchMetadata() (datasource.Metadata, error) {
+	return datasource.Metadata{}, nil
+}
+
+func (f *remoteFile) FetchUserdata() ([]byte, error) {
+	client := pkg.NewHttpClient()
+	return client.GetRetry(f.url)
+}
+
+func (f *remoteFile) Type() string {
+	return "url"
+}
--- a/datasource/vmware/vmware.go
+++ b/datasource/vmware/vmware.go
@@ -0,0 +1,183 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vmware
+
+import (
+	"fmt"
+	"log"
+	"net"
+
+	"github.com/coreos/coreos-cloudinit/config"
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/pkg"
+
+	"github.com/sigma/vmw-guestinfo/rpcvmx"
+	"github.com/sigma/vmw-guestinfo/vmcheck"
+)
+
+type readConfigFunction func(key string) (string, error)
+type urlDownloadFunction func(url string) ([]byte, error)
+
+type vmware struct {
+	readConfig  readConfigFunction
+	urlDownload urlDownloadFunction
+}
+
+func NewDatasource() *vmware {
+	return &vmware{
+		readConfig:  readConfig,
+		urlDownload: urlDownload,
+	}
+}
+
+func (v vmware) IsAvailable() bool {
+	return vmcheck.IsVirtualWorld()
+}
+
+func (v vmware) AvailabilityChanges() bool {
+	return false
+}
+
+func (v vmware) ConfigRoot() string {
+	return "/"
+}
+
+func (v vmware) FetchMetadata() (metadata datasource.Metadata, err error) {
+	metadata.Hostname, _ = v.readConfig("hostname")
+
+	netconf := map[string]string{}
+	saveConfig := func(key string, args ...interface{}) string {
+		key = fmt.Sprintf(key, args...)
+		val, _ := v.readConfig(key)
+		if val != "" {
+			netconf[key] = val
+		}
+		return val
+	}
+
+	for i := 0; ; i++ {
+		if nameserver := saveConfig("dns.server.%d", i); nameserver == "" {
+			break
+		}
+	}
+
+	found := true
+	for i := 0; found; i++ {
+		found = false
+
+		found = (saveConfig("interface.%d.name", i) != "") || found
+		found = (saveConfig("interface.%d.mac", i) != "") || found
+		found = (saveConfig("interface.%d.dhcp", i) != "") || found
+
+		role, _ := v.readConfig(fmt.Sprintf("interface.%d.role", i))
+		for a := 0; ; a++ {
+			address := saveConfig("interface.%d.ip.%d.address", i, a)
+			if address == "" {
+				break
+			} else {
+				found = true
+			}
+
+			ip, _, err := net.ParseCIDR(address)
+			if err != nil {
+				return metadata, err
+			}
+
+			switch role {
+			case "public":
+				if ip.To4() != nil {
+					metadata.PublicIPv4 = ip
+				} else {
+					metadata.PublicIPv6 = ip
+				}
+			case "private":
+				if ip.To4() != nil {
+					metadata.PrivateIPv4 = ip
+				} else {
+					metadata.PrivateIPv6 = ip
+				}
+			case "":
+			default:
+				return metadata, fmt.Errorf("unrecognized role: %q", role)
+			}
+		}
+
+		for r := 0; ; r++ {
+			gateway := saveConfig("interface.%d.route.%d.gateway", i, r)
+			destination := saveConfig("interface.%d.route.%d.destination", i, r)
+
+			if gateway == "" && destination == "" {
+				break
+			} else {
+				found = true
+			}
+		}
+	}
+	metadata.NetworkConfig = netconf
+
+	return
+}
+
+func (v vmware) FetchUserdata() ([]byte, error) {
+	encoding, err := v.readConfig("coreos.config.data.encoding")
+	if err != nil {
+		return nil, err
+	}
+
+	data, err := v.readConfig("coreos.config.data")
+	if err != nil {
+		return nil, err
+	}
+
+	// Try to fallback to url if no explicit data
+	if data == "" {
+		url, err := v.readConfig("coreos.config.url")
+		if err != nil {
+			return nil, err
+		}
+
+		if url != "" {
+			rawData, err := v.urlDownload(url)
+			if err != nil {
+				return nil, err
+			}
+			data = string(rawData)
+		}
+	}
+
+	if encoding != "" {
+		return config.DecodeContent(data, encoding)
+	}
+	return []byte(data), nil
+}
+
+func (v vmware) Type() string {
+	return "vmware"
+}
+
+func urlDownload(url string) ([]byte, error) {
+	client := pkg.NewHttpClient()
+	return client.GetRetry(url)
+}
+
+func readConfig(key string) (string, error) {
+	data, err := rpcvmx.NewConfig().GetString(key, "")
+	if err == nil {
+		log.Printf("Read from %q: %q\n", key, data)
+	} else {
+		log.Printf("Failed to read from %q: %v\n", key, err)
+	}
+	return data, err
+}
--- a/datasource/vmware/vmware_test.go
+++ b/datasource/vmware/vmware_test.go
@@ -0,0 +1,216 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vmware
+
+import (
+	"errors"
+	"net"
+	"reflect"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+)
+
+type MockHypervisor map[string]string
+
+func (h MockHypervisor) ReadConfig(key string) (string, error) {
+	return h[key], nil
+}
+
+func TestFetchMetadata(t *testing.T) {
+	tests := []struct {
+		variables MockHypervisor
+
+		metadata datasource.Metadata
+		err      error
+	}{
+		{
+			variables: map[string]string{
+				"interface.0.mac":  "test mac",
+				"interface.0.dhcp": "yes",
+			},
+			metadata: datasource.Metadata{
+				NetworkConfig: map[string]string{
+					"interface.0.mac":  "test mac",
+					"interface.0.dhcp": "yes",
+				},
+			},
+		},
+		{
+			variables: map[string]string{
+				"interface.0.name": "test name",
+				"interface.0.dhcp": "yes",
+			},
+			metadata: datasource.Metadata{
+				NetworkConfig: map[string]string{
+					"interface.0.name": "test name",
+					"interface.0.dhcp": "yes",
+				},
+			},
+		},
+		{
+			variables: map[string]string{
+				"hostname":                        "test host",
+				"interface.0.mac":                 "test mac",
+				"interface.0.role":                "private",
+				"interface.0.ip.0.address":        "fe00::100/64",
+				"interface.0.route.0.gateway":     "fe00::1",
+				"interface.0.route.0.destination": "::",
+			},
+			metadata: datasource.Metadata{
+				Hostname:    "test host",
+				PrivateIPv6: net.ParseIP("fe00::100"),
+				NetworkConfig: map[string]string{
+					"interface.0.mac":                 "test mac",
+					"interface.0.ip.0.address":        "fe00::100/64",
+					"interface.0.route.0.gateway":     "fe00::1",
+					"interface.0.route.0.destination": "::",
+				},
+			},
+		},
+		{
+			variables: map[string]string{
+				"hostname":                        "test host",
+				"interface.0.name":                "test name",
+				"interface.0.role":                "public",
+				"interface.0.ip.0.address":        "10.0.0.100/24",
+				"interface.0.ip.1.address":        "10.0.0.101/24",
+				"interface.0.route.0.gateway":     "10.0.0.1",
+				"interface.0.route.0.destination": "0.0.0.0",
+				"interface.1.mac":                 "test mac",
+				"interface.1.role":                "private",
+				"interface.1.route.0.gateway":     "10.0.0.2",
+				"interface.1.route.0.destination": "0.0.0.0",
+				"interface.1.ip.0.address":        "10.0.0.102/24",
+			},
+			metadata: datasource.Metadata{
+				Hostname:    "test host",
+				PublicIPv4:  net.ParseIP("10.0.0.101"),
+				PrivateIPv4: net.ParseIP("10.0.0.102"),
+				NetworkConfig: map[string]string{
+					"interface.0.name":                "test name",
+					"interface.0.ip.0.address":        "10.0.0.100/24",
+					"interface.0.ip.1.address":        "10.0.0.101/24",
+					"interface.0.route.0.gateway":     "10.0.0.1",
+					"interface.0.route.0.destination": "0.0.0.0",
+					"interface.1.mac":                 "test mac",
+					"interface.1.route.0.gateway":     "10.0.0.2",
+					"interface.1.route.0.destination": "0.0.0.0",
+					"interface.1.ip.0.address":        "10.0.0.102/24",
+				},
+			},
+		},
+	}
+
+	for i, tt := range tests {
+		v := vmware{readConfig: tt.variables.ReadConfig}
+		metadata, err := v.FetchMetadata()
+		if !reflect.DeepEqual(tt.err, err) {
+			t.Errorf("bad error (#%d): want %v, got %v", i, tt.err, err)
+		}
+		if !reflect.DeepEqual(tt.metadata, metadata) {
+			t.Errorf("bad metadata (#%d): want %#v, got %#v", i, tt.metadata, metadata)
+		}
+	}
+}
+
+func TestFetchUserdata(t *testing.T) {
+	tests := []struct {
+		variables MockHypervisor
+
+		userdata string
+		err      error
+	}{
+		{},
+		{
+			variables: map[string]string{"coreos.config.data": "test config"},
+			userdata:  "test config",
+		},
+		{
+			variables: map[string]string{
+				"coreos.config.data.encoding": "",
+				"coreos.config.data":          "test config",
+			},
+			userdata: "test config",
+		},
+		{
+			variables: map[string]string{
+				"coreos.config.data.encoding": "base64",
+				"coreos.config.data":          "dGVzdCBjb25maWc=",
+			},
+			userdata: "test config",
+		},
+		{
+			variables: map[string]string{
+				"coreos.config.data.encoding": "gzip+base64",
+				"coreos.config.data":          "H4sIABaoWlUAAytJLS5RSM7PS8tMBwCQiHNZCwAAAA==",
+			},
+			userdata: "test config",
+		},
+		{
+			variables: map[string]string{
+				"coreos.config.data.encoding": "test encoding",
+			},
+			err: errors.New(`Unsupported encoding "test encoding"`),
+		},
+		{
+			variables: map[string]string{
+				"coreos.config.url": "http://good.example.com",
+			},
+			userdata: "test config",
+		},
+		{
+			variables: map[string]string{
+				"coreos.config.url": "http://bad.example.com",
+			},
+			err: errors.New("Not found"),
+		},
+	}
+
+	var downloader urlDownloadFunction = func(url string) ([]byte, error) {
+		mapping := map[string]struct {
+			data []byte
+			err  error
+		}{
+			"http://good.example.com": {[]byte("test config"), nil},
+			"http://bad.example.com":  {nil, errors.New("Not found")},
+		}
+		val := mapping[url]
+		return val.data, val.err
+	}
+
+	for i, tt := range tests {
+		v := vmware{
+			readConfig:  tt.variables.ReadConfig,
+			urlDownload: downloader,
+		}
+		userdata, err := v.FetchUserdata()
+		if !reflect.DeepEqual(tt.err, err) {
+			t.Errorf("bad error (#%d): want %v, got %v", i, tt.err, err)
+		}
+		if tt.userdata != string(userdata) {
+			t.Errorf("bad userdata (#%d): want %q, got %q", i, tt.userdata, userdata)
+		}
+	}
+}
+
+func TestFetchUserdataError(t *testing.T) {
+	testErr := errors.New("test error")
+	_, err := vmware{readConfig: func(_ string) (string, error) { return "", testErr }}.FetchUserdata()
+
+	if testErr != err {
+		t.Errorf("bad error: want %v, got %v", testErr, err)
+	}
+}
--- a/datasource/waagent/waagent.go
+++ b/datasource/waagent/waagent.go
@@ -0,0 +1,117 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package waagent
+
+import (
+	"encoding/xml"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+	"path"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+)
+
+type waagent struct {
+	root     string
+	readFile func(filename string) ([]byte, error)
+}
+
+func NewDatasource(root string) *waagent {
+	return &waagent{root, ioutil.ReadFile}
+}
+
+func (a *waagent) IsAvailable() bool {
+	_, err := os.Stat(path.Join(a.root, "provisioned"))
+	return !os.IsNotExist(err)
+}
+
+func (a *waagent) AvailabilityChanges() bool {
+	return true
+}
+
+func (a *waagent) ConfigRoot() string {
+	return a.root
+}
+
+func (a *waagent) FetchMetadata() (metadata datasource.Metadata, err error) {
+	var metadataBytes []byte
+	if metadataBytes, err = a.tryReadFile(path.Join(a.root, "SharedConfig.xml")); err != nil {
+		return
+	}
+	if len(metadataBytes) == 0 {
+		return
+	}
+
+	type Instance struct {
+		Id             string `xml:"id,attr"`
+		Address        string `xml:"address,attr"`
+		InputEndpoints struct {
+			Endpoints []struct {
+				LoadBalancedPublicAddress string `xml:"loadBalancedPublicAddress,attr"`
+			} `xml:"Endpoint"`
+		}
+	}
+
+	type SharedConfig struct {
+		Incarnation struct {
+			Instance string `xml:"instance,attr"`
+		}
+		Instances struct {
+			Instances []Instance `xml:"Instance"`
+		}
+	}
+
+	var m SharedConfig
+	if err = xml.Unmarshal(metadataBytes, &m); err != nil {
+		return
+	}
+
+	var instance Instance
+	for _, i := range m.Instances.Instances {
+		if i.Id == m.Incarnation.Instance {
+			instance = i
+			break
+		}
+	}
+
+	metadata.PrivateIPv4 = net.ParseIP(instance.Address)
+	for _, e := range instance.InputEndpoints.Endpoints {
+		host, _, err := net.SplitHostPort(e.LoadBalancedPublicAddress)
+		if err == nil {
+			metadata.PublicIPv4 = net.ParseIP(host)
+			break
+		}
+	}
+	return
+}
+
+func (a *waagent) FetchUserdata() ([]byte, error) {
+	return a.tryReadFile(path.Join(a.root, "CustomData"))
+}
+
+func (a *waagent) Type() string {
+	return "waagent"
+}
+
+func (a *waagent) tryReadFile(filename string) ([]byte, error) {
+	log.Printf("Attempting to read from %q\n", filename)
+	data, err := a.readFile(filename)
+	if os.IsNotExist(err) {
+		err = nil
+	}
+	return data, err
+}
--- a/datasource/waagent/waagent_test.go
+++ b/datasource/waagent/waagent_test.go
@@ -0,0 +1,166 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package waagent
+
+import (
+	"net"
+	"reflect"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/datasource/test"
+)
+
+func TestFetchMetadata(t *testing.T) {
+	for _, tt := range []struct {
+		root     string
+		files    test.MockFilesystem
+		metadata datasource.Metadata
+	}{
+		{
+			root:  "/",
+			files: test.NewMockFilesystem(),
+		},
+		{
+			root:  "/",
+			files: test.NewMockFilesystem(test.File{Path: "/SharedConfig.xml", Contents: ""}),
+		},
+		{
+			root:  "/var/lib/waagent",
+			files: test.NewMockFilesystem(test.File{Path: "/var/lib/waagent/SharedConfig.xml", Contents: ""}),
+		},
+		{
+			root: "/var/lib/waagent",
+			files: test.NewMockFilesystem(test.File{Path: "/var/lib/waagent/SharedConfig.xml", Contents: `<?xml version="1.0" encoding="utf-8"?>
+<SharedConfig version="1.0.0.0" goalStateIncarnation="1">
+  <Deployment name="c8f9e4c9c18948e1bebf57c5685da756" guid="{1d10394f-c741-4a1a-a6bb-278f213c5a5e}" incarnation="0" isNonCancellableTopologyChangeEnabled="false">
+    <Service name="core-test-1" guid="{00000000-0000-0000-0000-000000000000}" />
+    <ServiceInstance name="c8f9e4c9c18948e1bebf57c5685da756.0" guid="{1e202e9a-8ffe-4915-b6ef-4118c9628fda}" />
+  </Deployment>
+  <Incarnation number="1" instance="core-test-1" guid="{8767eb4b-b445-4783-b1f5-6c0beaf41ea0}" />
+  <Role guid="{53ecc81e-257f-fbc9-a53a-8cf1a0a122b4}" name="core-test-1" settleTimeSeconds="0" />
+  <LoadBalancerSettings timeoutSeconds="0" waitLoadBalancerProbeCount="8">
+    <Probes>
+      <Probe name="D41D8CD98F00B204E9800998ECF8427E" />
+      <Probe name="C9DEC1518E1158748FA4B6081A8266DD" />
+    </Probes>
+  </LoadBalancerSettings>
+  <OutputEndpoints>
+    <Endpoint name="core-test-1:openInternalEndpoint" type="SFS">
+      <Target instance="core-test-1" endpoint="openInternalEndpoint" />
+    </Endpoint>
+  </OutputEndpoints>
+  <Instances>
+    <Instance id="core-test-1" address="100.73.202.64">
+      <FaultDomains randomId="0" updateId="0" updateCount="0" />
+      <InputEndpoints>
+        <Endpoint name="openInternalEndpoint" address="100.73.202.64" protocol="any" isPublic="false" enableDirectServerReturn="false" isDirectAddress="false" disableStealthMode="false">
+          <LocalPorts>
+            <LocalPortSelfManaged />
+          </LocalPorts>
+        </Endpoint>
+        <Endpoint name="ssh" address="100.73.202.64:22" protocol="tcp" hostName="core-test-1ContractContract" isPublic="true" loadBalancedPublicAddress="191.239.39.77:22" enableDirectServerReturn="false" isDirectAddress="false" disableStealthMode="false">
+          <LocalPorts>
+            <LocalPortRange from="22" to="22" />
+          </LocalPorts>
+        </Endpoint>
+      </InputEndpoints>
+    </Instance>
+  </Instances>
+</SharedConfig>`}),
+			metadata: datasource.Metadata{
+				PrivateIPv4: net.ParseIP("100.73.202.64"),
+				PublicIPv4:  net.ParseIP("191.239.39.77"),
+			},
+		},
+	} {
+		a := waagent{tt.root, tt.files.ReadFile}
+		metadata, err := a.FetchMetadata()
+		if err != nil {
+			t.Fatalf("bad error for %+v: want %v, got %q", tt, nil, err)
+		}
+		if !reflect.DeepEqual(tt.metadata, metadata) {
+			t.Fatalf("bad metadata for %+v: want %#v, got %#v", tt, tt.metadata, metadata)
+		}
+	}
+}
+
+func TestFetchUserdata(t *testing.T) {
+	for _, tt := range []struct {
+		root  string
+		files test.MockFilesystem
+	}{
+		{
+			"/",
+			test.NewMockFilesystem(),
+		},
+		{
+			"/",
+			test.NewMockFilesystem(test.File{Path: "/CustomData", Contents: ""}),
+		},
+		{
+			"/var/lib/waagent/",
+			test.NewMockFilesystem(test.File{Path: "/var/lib/waagent/CustomData", Contents: ""}),
+		},
+	} {
+		a := waagent{tt.root, tt.files.ReadFile}
+		_, err := a.FetchUserdata()
+		if err != nil {
+			t.Fatalf("bad error for %+v: want %v, got %q", tt, nil, err)
+		}
+	}
+}
+
+func TestConfigRoot(t *testing.T) {
+	for _, tt := range []struct {
+		root       string
+		configRoot string
+	}{
+		{
+			"/",
+			"/",
+		},
+		{
+			"/var/lib/waagent",
+			"/var/lib/waagent",
+		},
+	} {
+		a := waagent{tt.root, nil}
+		if configRoot := a.ConfigRoot(); configRoot != tt.configRoot {
+			t.Fatalf("bad config root for %q: want %q, got %q", tt, tt.configRoot, configRoot)
+		}
+	}
+}
+
+func TestNewDatasource(t *testing.T) {
+	for _, tt := range []struct {
+		root       string
+		expectRoot string
+	}{
+		{
+			root:       "",
+			expectRoot: "",
+		},
+		{
+			root:       "/var/lib/waagent",
+			expectRoot: "/var/lib/waagent",
+		},
+	} {
+		service := NewDatasource(tt.root)
+		if service.root != tt.expectRoot {
+			t.Fatalf("bad root (%q): want %q, got %q", tt.root, tt.expectRoot, service.root)
+		}
+	}
+}
--- a/extra/systemd/90-configdrive.rules
+++ b/extra/systemd/90-configdrive.rules
@@ -3,9 +3,9 @@
 ACTION!="add|change", GOTO="coreos_configdrive_end"

 # A normal config drive. Block device formatted with iso9660 or fat
-SUBSYSTEM=="block", ENV{ID_FS_TYPE}=="iso9660|vfat", ENV{ID_FS_LABEL}=="config-2", TAG+="systemd", ENV{SYSTEMD_WANTS}+="configdrive-block.service"
+SUBSYSTEM=="block", ENV{ID_FS_TYPE}=="iso9660|vfat", ENV{ID_FS_LABEL}=="config-2", TAG+="systemd", ENV{SYSTEMD_WANTS}+="media-configdrive.mount"

 # Addtionally support virtfs from QEMU
-SUBSYSTEM=="virtio", DRIVER=="9pnet_virtio", ATTR{mount_tag}=="config-2", TAG+="systemd", ENV{SYSTEMD_WANTS}+="configdrive-virtfs.service"
+SUBSYSTEM=="virtio", DRIVER=="9pnet_virtio", ATTR{mount_tag}=="config-2", TAG+="systemd", ENV{SYSTEMD_WANTS}+="media-configvirtfs.mount"

 LABEL="coreos_configdrive_end"
--- a/extra/systemd/media-configdrive.mount
+++ b/extra/systemd/media-configdrive.mount
@@ -0,0 +1,13 @@
+[Unit]
+Wants=user-configdrive.service
+Before=user-configdrive.service
+# Only mount config drive block devices automatically in virtual machines
+# or any host that has it explicitly enabled and not explicitly disabled.
+ConditionVirtualization=|vm
+ConditionKernelCommandLine=|coreos.configdrive=1
+ConditionKernelCommandLine=!coreos.configdrive=0
+
+[Mount]
+What=LABEL=config-2
+Where=/media/configdrive
+Options=ro
--- a/extra/systemd/media-configvirtfs.mount
+++ b/extra/systemd/media-configvirtfs.mount
@@ -0,0 +1,18 @@
+[Unit]
+Wants=user-configvirtfs.service
+Before=user-configvirtfs.service
+# Only mount config drive block devices automatically in virtual machines
+# or any host that has it explicitly enabled and not explicitly disabled.
+ConditionVirtualization=|vm
+ConditionKernelCommandLine=|coreos.configdrive=1
+ConditionKernelCommandLine=!coreos.configdrive=0
+
+# Support old style setup for now
+Wants=addon-run@media-configvirtfs.service addon-config@media-configvirtfs.service
+Before=addon-run@media-configvirtfs.service addon-config@media-configvirtfs.service
+
+[Mount]
+What=config-2
+Where=/media/configvirtfs
+Options=ro,trans=virtio,version=9p2000.L
+Type=9p
--- a/extra/systemd/system-cloudinit@.service
+++ b/extra/systemd/system-cloudinit@.service
--- a/extra/systemd/system-config.target
+++ b/extra/systemd/system-config.target
--- a/extra/systemd/user-cloudinit-proc-cmdline.service
+++ b/extra/systemd/user-cloudinit-proc-cmdline.service
--- a/extra/systemd/user-cloudinit@.path
+++ b/extra/systemd/user-cloudinit@.path
--- a/extra/systemd/user-cloudinit@.service
+++ b/extra/systemd/user-cloudinit@.service
--- a/extra/systemd/user-config.target
+++ b/extra/systemd/user-config.target
--- a/extra/systemd/user-configdrive.path
+++ b/extra/systemd/user-configdrive.path
@@ -0,0 +1,10 @@
+[Unit]
+Description=Watch for a cloud-config at /media/configdrive
+
+# Note: This unit is essentially just here as a fall-back mechanism to
+# trigger cloudinit if it isn't triggered explicitly by other means
+# such as by a Wants= in the mount unit. This ensures we handle the
+# case where /media/configdrive is provided to a CoreOS container.
+
+[Path]
+DirectoryNotEmpty=/media/configdrive
--- a/extra/systemd/user-configdrive.service
+++ b/extra/systemd/user-configdrive.service
@@ -1,7 +1,7 @@
 [Unit]
 Description=Load cloud-config from /media/configdrive
 Requires=coreos-setup-environment.service
-After=coreos-setup-environment.service
+After=coreos-setup-environment.service system-config.target
 Before=user-config.target

 # HACK: work around ordering between config drive and ec2 metadata It is
@@ -13,7 +13,6 @@ Before=user-config.target
 # systemd knows about the ordering as early as possible.
 # coreos-cloudinit could implement a simple lock but that cannot be used
 # until after the systemd dbus calls are made non-blocking.
-After=system-cloudinit@usr-share-oem-cloud\x2dconfig.yml.service
 After=ec2-cloudinit.service

 [Service]
--- a/extra/systemd/user-configvirtfs.service
+++ b/extra/systemd/user-configvirtfs.service
@@ -0,0 +1,11 @@
+[Unit]
+Description=Load cloud-config from /media/configvirtfs
+Requires=coreos-setup-environment.service
+After=coreos-setup-environment.service
+Before=user-config.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+EnvironmentFile=-/etc/environment
+ExecStart=/usr/bin/coreos-cloudinit --from-configdrive=/media/configvirtfs
--- a/initialize/config.go
+++ b/initialize/config.go
@@ -1,12 +1,30 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package initialize

 import (
 	"errors"
 	"fmt"
 	"log"
+	"os"
+	"os/exec"
+	"path"
+	"strings"

-	"github.com/coreos/coreos-cloudinit/third_party/launchpad.net/goyaml"
-
+	"github.com/coreos/coreos-cloudinit/config"
+	"github.com/coreos/coreos-cloudinit/network"
 	"github.com/coreos/coreos-cloudinit/system"
 )

@@ -15,138 +33,56 @@ import (
 type CloudConfigFile interface {
 	// File should either return (*system.File, error), or (nil, nil) if nothing
 	// needs to be done for this configuration option.
-	File(root string) (*system.File, error)
+	File() (*system.File, error)
 }

 // CloudConfigUnit represents a CoreOS specific configuration option that can generate
 // associated system.Units to be created/enabled appropriately
 type CloudConfigUnit interface {
-	Units(root string) ([]system.Unit, error)
+	Units() []system.Unit
 }

-// CloudConfig encapsulates the entire cloud-config configuration file and maps directly to YAML
-type CloudConfig struct {
-	SSHAuthorizedKeys []string `yaml:"ssh_authorized_keys"`
-	Coreos            struct {
-		Etcd   EtcdEnvironment
-		Fleet  FleetEnvironment
-		OEM    OEMRelease
-		Update UpdateConfig
-		Units  []system.Unit
+func isLock(env *Environment) bool {
+	if _, err := os.Stat(path.Join(env.Workspace(), ".lock")); err != nil {
+		return false
 	}
-	WriteFiles     []system.File `yaml:"write_files"`
-	Hostname       string
-	Users          []system.User
-	ManageEtcHosts EtcHosts `yaml:"manage_etc_hosts"`
+	return true
 }

-type warner func(format string, v ...interface{})
-
-// warnOnUnrecognizedKeys parses the contents of a cloud-config file and calls
-// warn(msg, key) for every unrecognized key (i.e. those not present in CloudConfig)
-func warnOnUnrecognizedKeys(contents string, warn warner) {
-	// Generate a map of all understood cloud config options
-	var cc map[string]interface{}
-	b, _ := goyaml.Marshal(&CloudConfig{})
-	goyaml.Unmarshal(b, &cc)
-
-	// Now unmarshal the entire provided contents
-	var c map[string]interface{}
-	goyaml.Unmarshal([]byte(contents), &c)
-
-	// Check that every key in the contents exists in the cloud config
-	for k, _ := range c {
-		if _, ok := cc[k]; !ok {
-			warn("Warning: unrecognized key %q in provided cloud config - ignoring section", k)
+func Lock(env *Environment) error {
+	if !isLock(env) {
+		fp, err := os.OpenFile(path.Join(env.Workspace(), ".lock"), os.O_WRONLY|os.O_CREATE|os.O_EXCL|os.O_TRUNC, os.FileMode(0644))
+		if err != nil {
+			return err
 		}
+		return fp.Close()
 	}
-
-	// Check for unrecognized coreos options, if any are set
-	coreos, ok := c["coreos"]
-	if ok {
-		set := coreos.(map[interface{}]interface{})
-		known := cc["coreos"].(map[interface{}]interface{})
-		for k, _ := range set {
-			key := k.(string)
-			if _, ok := known[key]; !ok {
-				warn("Warning: unrecognized key %q in coreos section of provided cloud config - ignoring", key)
-			}
-		}
-	}
-
-	// Check for any badly-specified users, if any are set
-	users, ok := c["users"]
-	if ok {
-		var known map[string]interface{}
-		b, _ := goyaml.Marshal(&system.User{})
-		goyaml.Unmarshal(b, &known)
-
-		set := users.([]interface{})
-		for _, u := range set {
-			user := u.(map[interface{}]interface{})
-			for k, _ := range user {
-				key := k.(string)
-				if _, ok := known[key]; !ok {
-					warn("Warning: unrecognized key %q in user section of cloud config - ignoring", key)
-				}
-			}
-		}
-	}
-
-	// Check for any badly-specified files, if any are set
-	files, ok := c["write_files"]
-	if ok {
-		var known map[string]interface{}
-		b, _ := goyaml.Marshal(&system.File{})
-		goyaml.Unmarshal(b, &known)
-
-		set := files.([]interface{})
-		for _, f := range set {
-			file := f.(map[interface{}]interface{})
-			for k, _ := range file {
-				key := k.(string)
-				if _, ok := known[key]; !ok {
-					warn("Warning: unrecognized key %q in file section of cloud config - ignoring", key)
-				}
-			}
-		}
-	}
-}
-
-// NewCloudConfig instantiates a new CloudConfig from the given contents (a
-// string of YAML), returning any error encountered. It will ignore unknown
-// fields but log encountering them.
-func NewCloudConfig(contents string) (*CloudConfig, error) {
-	var cfg CloudConfig
-	err := goyaml.Unmarshal([]byte(contents), &cfg)
-	if err != nil {
-		return &cfg, err
-	}
-	warnOnUnrecognizedKeys(contents, log.Printf)
-	return &cfg, nil
-}
-
-func (cc CloudConfig) String() string {
-	bytes, err := goyaml.Marshal(cc)
-	if err != nil {
-		return ""
-	}
-
-	stringified := string(bytes)
-	stringified = fmt.Sprintf("#cloud-config\n%s", stringified)
-
-	return stringified
+	return nil
 }

 // Apply renders a CloudConfig to an Environment. This can involve things like
 // configuring the hostname, adding new users, writing various configuration
 // files to disk, and manipulating systemd services.
-func Apply(cfg CloudConfig, env *Environment) error {
-	if cfg.Hostname != "" {
-		if err := system.SetHostname(cfg.Hostname); err != nil {
-			return err
+func Apply(cfg config.CloudConfig, ifaces []network.InterfaceGenerator, env *Environment) error {
+	var err error
+
+	for _, cmdline := range cfg.RunCMD {
+		prog := strings.Fields(cmdline)[0]
+		args := strings.Fields(cmdline)[1:]
+		exec.Command(prog, args...).Run()
+	}
+
+	if err = os.MkdirAll(env.Workspace(), os.FileMode(0755)); err != nil {
+		return err
+	}
+
+	if !isLock(env) {
+		if cfg.Hostname != "" {
+			if err = system.SetHostname(cfg.Hostname); err != nil {
+				return err
+			}
+			log.Printf("Set hostname to %s", cfg.Hostname)
 		}
-		log.Printf("Set hostname to %s", cfg.Hostname)
 	}

 	for _, user := range cfg.Users {
@@ -155,135 +91,258 @@ func Apply(cfg CloudConfig, env *Environment) error {
 			continue
 		}

-		if system.UserExists(&user) {
-			log.Printf("User '%s' exists, ignoring creation-time fields", user.Name)
-			if user.PasswordHash != "" {
-				log.Printf("Setting '%s' user's password", user.Name)
-				if err := system.SetUserPassword(user.Name, user.PasswordHash); err != nil {
-					log.Printf("Failed setting '%s' user's password: %v", user.Name, err)
+		if !isLock(env) {
+			if system.UserExists(&user) {
+				log.Printf("User '%s' exists, ignoring creation-time fields", user.Name)
+				if user.PasswordHash != "" {
+					log.Printf("Setting '%s' user's password", user.Name)
+					if err := system.SetUserPassword(user.Name, user.PasswordHash); err != nil {
+						log.Printf("Failed setting '%s' user's password: %v", user.Name, err)
+						return err
+					}
+				}
+			} else {
+				log.Printf("Creating user '%s'", user.Name)
+				if err = system.CreateUser(&user); err != nil {
+					log.Printf("Failed creating user '%s': %v", user.Name, err)
 					return err
 				}
 			}
-		} else {
-			log.Printf("Creating user '%s'", user.Name)
-			if err := system.CreateUser(&user); err != nil {
-				log.Printf("Failed creating user '%s': %v", user.Name, err)
+
+			if err = system.LockUnlockUser(&user); err != nil {
+				log.Printf("Failed lock/unlock user '%s': %v", user.Name, err)
 				return err
 			}
 		}

 		if len(user.SSHAuthorizedKeys) > 0 {
 			log.Printf("Authorizing %d SSH keys for user '%s'", len(user.SSHAuthorizedKeys), user.Name)
-			if err := system.AuthorizeSSHKeys(user.Name, env.SSHKeyName(), user.SSHAuthorizedKeys); err != nil {
+			if err = system.AuthorizeSSHKeys(user.Name, env.SSHKeyName(), user.SSHAuthorizedKeys); err != nil {
 				return err
 			}
 		}
 		if user.SSHImportGithubUser != "" {
 			log.Printf("Authorizing github user %s SSH keys for CoreOS user '%s'", user.SSHImportGithubUser, user.Name)
-			if err := SSHImportGithubUser(user.Name, user.SSHImportGithubUser); err != nil {
+			if err = SSHImportGithubUser(user.Name, user.SSHImportGithubUser); err != nil {
+				return err
+			}
+		}
+		for _, u := range user.SSHImportGithubUsers {
+			log.Printf("Authorizing github user %s SSH keys for CoreOS user '%s'", u, user.Name)
+			if err = SSHImportGithubUser(user.Name, u); err != nil {
 				return err
 			}
 		}
 		if user.SSHImportURL != "" {
 			log.Printf("Authorizing SSH keys for CoreOS user '%s' from '%s'", user.Name, user.SSHImportURL)
-			if err := SSHImportKeysFromURL(user.Name, user.SSHImportURL); err != nil {
+			if err = SSHImportKeysFromURL(user.Name, user.SSHImportURL); err != nil {
 				return err
 			}
 		}
 	}

 	if len(cfg.SSHAuthorizedKeys) > 0 {
-		err := system.AuthorizeSSHKeys("core", env.SSHKeyName(), cfg.SSHAuthorizedKeys)
+		err = system.AuthorizeSSHKeys(cfg.SystemInfo.DefaultUser.Name, env.SSHKeyName(), cfg.SSHAuthorizedKeys)
 		if err == nil {
-			log.Printf("Authorized SSH keys for core user")
+			log.Printf("Authorized SSH keys for %s user", cfg.SystemInfo.DefaultUser.Name)
 		} else {
 			return err
 		}
 	}

-	for _, ccf := range []CloudConfigFile{cfg.Coreos.OEM, cfg.Coreos.Update, cfg.ManageEtcHosts} {
-		f, err := ccf.File(env.Root())
-		if err != nil {
-			return err
+	if !isLock(env) {
+		var writeFiles []system.File
+		for _, file := range cfg.WriteFiles {
+			writeFiles = append(writeFiles, system.File{File: file})
 		}
-		if f != nil {
-			cfg.WriteFiles = append(cfg.WriteFiles, *f)
-		}
-	}

-	for _, ccu := range []CloudConfigUnit{cfg.Coreos.Etcd, cfg.Coreos.Fleet, cfg.Coreos.Update} {
-		u, err := ccu.Units(env.Root())
-		if err != nil {
-			return err
-		}
-		cfg.Coreos.Units = append(cfg.Coreos.Units, u...)
-	}
-
-	for _, file := range cfg.WriteFiles {
-		path, err := system.WriteFile(&file, env.Root())
-		if err != nil {
-			return err
-		}
-		log.Printf("Wrote file %s to filesystem", path)
-	}
-
-	commands := make(map[string]string, 0)
-	reload := false
-	for _, unit := range cfg.Coreos.Units {
-		dst := unit.Destination(env.Root())
-		if unit.Content != "" {
-			log.Printf("Writing unit %s to filesystem at path %s", unit.Name, dst)
-			if err := system.PlaceUnit(&unit, dst); err != nil {
+		for _, ccf := range []CloudConfigFile{
+			system.OEM{OEM: cfg.CoreOS.OEM},
+			system.Update{Update: cfg.CoreOS.Update, ReadConfig: system.DefaultReadConfig},
+			system.EtcHosts{EtcHosts: cfg.ManageEtcHosts},
+			system.Flannel{Flannel: cfg.CoreOS.Flannel},
+		} {
+			f, err := ccf.File()
+			if err != nil {
 				return err
 			}
-			log.Printf("Placed unit %s at %s", unit.Name, dst)
+			if f != nil {
+				writeFiles = append(writeFiles, *f)
+			}
+		}
+
+		var units []system.Unit
+		for _, u := range cfg.CoreOS.Units {
+			units = append(units, system.Unit{Unit: u})
+		}
+
+		for _, ccu := range []CloudConfigUnit{
+			system.Etcd{Etcd: cfg.CoreOS.Etcd},
+			system.Etcd2{Etcd2: cfg.CoreOS.Etcd2},
+			system.Fleet{Fleet: cfg.CoreOS.Fleet},
+			system.Locksmith{Locksmith: cfg.CoreOS.Locksmith},
+			system.Update{Update: cfg.CoreOS.Update, ReadConfig: system.DefaultReadConfig},
+		} {
+			units = append(units, ccu.Units()...)
+		}
+
+		wroteEnvironment := false
+		for _, file := range writeFiles {
+			fullPath, err := system.WriteFile(&file, env.Root())
+			if err != nil {
+				return err
+			}
+			if path.Clean(file.Path) == "/etc/environment" {
+				wroteEnvironment = true
+			}
+			log.Printf("Wrote file %s to filesystem", fullPath)
+		}
+
+		if !wroteEnvironment {
+			ef := env.DefaultEnvironmentFile()
+			if ef != nil {
+				err := system.WriteEnvFile(ef, env.Root())
+				if err != nil {
+					return err
+				}
+				log.Printf("Updated /etc/environment")
+			}
+		}
+
+		if len(ifaces) > 0 {
+			units = append(units, createNetworkingUnits(ifaces)...)
+			if err = system.RestartNetwork(ifaces); err != nil {
+				return err
+			}
+		}
+
+		um := system.NewUnitManager(env.Root())
+		if err = processUnits(units, env.Root(), um); err != nil {
+			return err
+		}
+	}
+
+	if cfg.ResizeRootfs {
+		log.Printf("resize root filesystem")
+		if err = system.ResizeRootFS(); err != nil {
+			return err
+		}
+	}
+
+	return Lock(env)
+}
+
+func createNetworkingUnits(interfaces []network.InterfaceGenerator) (units []system.Unit) {
+	appendNewUnit := func(units []system.Unit, name, content string) []system.Unit {
+		if content == "" {
+			return units
+		}
+		return append(units, system.Unit{Unit: config.Unit{
+			Name:    name,
+			Runtime: true,
+			Content: content,
+		}})
+	}
+	for _, i := range interfaces {
+		units = appendNewUnit(units, fmt.Sprintf("%s.netdev", i.Filename()), i.Netdev())
+		units = appendNewUnit(units, fmt.Sprintf("%s.link", i.Filename()), i.Link())
+		units = appendNewUnit(units, fmt.Sprintf("%s.network", i.Filename()), i.Network())
+	}
+	return units
+}
+
+// processUnits takes a set of Units and applies them to the given root using
+// the given UnitManager. This can involve things like writing unit files to
+// disk, masking/unmasking units, or invoking systemd
+// commands against units. It returns any error encountered.
+func processUnits(units []system.Unit, root string, um system.UnitManager) error {
+	type action struct {
+		unit    system.Unit
+		command string
+	}
+	actions := make([]action, 0, len(units))
+	reload := false
+	restartNetworkd := false
+	for _, unit := range units {
+		if unit.Name == "" {
+			log.Printf("Skipping unit without name")
+			continue
+		}
+
+		if unit.Content != "" {
+			log.Printf("Writing unit %q to filesystem", unit.Name)
+			if err := um.PlaceUnit(unit); err != nil {
+				return err
+			}
+			log.Printf("Wrote unit %q", unit.Name)
 			reload = true
 		}

+		for _, dropin := range unit.DropIns {
+			if dropin.Name != "" && dropin.Content != "" {
+				log.Printf("Writing drop-in unit %q to filesystem", dropin.Name)
+				if err := um.PlaceUnitDropIn(unit, dropin); err != nil {
+					return err
+				}
+				log.Printf("Wrote drop-in unit %q", dropin.Name)
+				reload = true
+			}
+		}
+
 		if unit.Mask {
-			log.Printf("Masking unit file %s", unit.Name)
-			if err := system.MaskUnit(&unit, env.Root()); err != nil {
+			log.Printf("Masking unit file %q", unit.Name)
+			if err := um.MaskUnit(unit); err != nil {
 				return err
 			}
 		} else if unit.Runtime {
-			log.Printf("Ensuring runtime unit file %s is unmasked", unit.Name)
-			if err := system.UnmaskUnit(&unit, env.Root()); err != nil {
+			log.Printf("Ensuring runtime unit file %q is unmasked", unit.Name)
+			if err := um.UnmaskUnit(unit); err != nil {
 				return err
 			}
 		}

 		if unit.Enable {
 			if unit.Group() != "network" {
-				log.Printf("Enabling unit file %s", unit.Name)
-				if err := system.EnableUnitFile(unit.Name, unit.Runtime); err != nil {
+				log.Printf("Enabling unit file %q", unit.Name)
+				if err := um.EnableUnitFile(unit); err != nil {
 					return err
 				}
-				log.Printf("Enabled unit %s", unit.Name)
+				log.Printf("Enabled unit %q", unit.Name)
 			} else {
-				log.Printf("Skipping enable for network-like unit %s", unit.Name)
+				log.Printf("Skipping enable for network-like unit %q", unit.Name)
 			}
 		}

 		if unit.Group() == "network" {
-			commands["systemd-networkd.service"] = "restart"
+			restartNetworkd = true
 		} else if unit.Command != "" {
-			commands[unit.Name] = unit.Command
+			actions = append(actions, action{unit, unit.Command})
 		}
 	}

 	if reload {
-		if err := system.DaemonReload(); err != nil {
-			return errors.New(fmt.Sprintf("failed systemd daemon-reload: %v", err))
+		if err := um.DaemonReload(); err != nil {
+			return errors.New(fmt.Sprintf("failed systemd daemon-reload: %s", err))
 		}
 	}

-	for unit, command := range commands {
-		log.Printf("Calling unit command '%s %s'", command, unit)
-		res, err := system.RunUnitCommand(command, unit)
+	if restartNetworkd {
+		log.Printf("Restarting systemd-networkd")
+		networkd := system.Unit{Unit: config.Unit{Name: "systemd-networkd.service"}}
+		res, err := um.RunUnitCommand(networkd, "restart")
 		if err != nil {
 			return err
 		}
-		log.Printf("Result of '%s %s': %s", command, unit, res)
+		log.Printf("Restarted systemd-networkd (%s)", res)
+	}
+
+	for _, action := range actions {
+		log.Printf("Calling unit command %q on %q'", action.command, action.unit.Name)
+		res, err := um.RunUnitCommand(action.unit, action.command)
+		if err != nil {
+			return err
+		}
+		log.Printf("Result of %q on %q: %s", action.command, action.unit.Name, res)
 	}

 	return nil
--- a/initialize/config_test.go
+++ b/initialize/config_test.go
@@ -1,334 +1,299 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package initialize

 import (
-	"fmt"
-	"strings"
+	"reflect"
 	"testing"
+
+	"github.com/coreos/coreos-cloudinit/config"
+	"github.com/coreos/coreos-cloudinit/network"
+	"github.com/coreos/coreos-cloudinit/system"
 )

-func TestCloudConfigUnknownKeys(t *testing.T) {
-	contents := `
-coreos: 
-  etcd:
-    discovery: "https://discovery.etcd.io/827c73219eeb2fa5530027c37bf18877"
-  coreos_unknown:
-    foo: "bar"
-section_unknown:
-  dunno:
-    something
-bare_unknown:
-  bar
-write_files:
-  - content: fun
-    path: /var/party
-    file_unknown: nofun
-users:
-  - name: fry
-    passwd: somehash
-    user_unknown: philip
-hostname:
-  foo
-`
-	cfg, err := NewCloudConfig(contents)
-	if err != nil {
-		t.Fatalf("error instantiating CloudConfig with unknown keys: %v", err)
-	}
-	if cfg.Hostname != "foo" {
-		t.Fatalf("hostname not correctly set when invalid keys are present")
-	}
-	if len(cfg.Coreos.Etcd) < 1 {
-		t.Fatalf("etcd section not correctly set when invalid keys are present")
-	}
-	if len(cfg.WriteFiles) < 1 || cfg.WriteFiles[0].Content != "fun" || cfg.WriteFiles[0].Path != "/var/party" {
-		t.Fatalf("write_files section not correctly set when invalid keys are present")
-	}
-	if len(cfg.Users) < 1 || cfg.Users[0].Name != "fry" || cfg.Users[0].PasswordHash != "somehash" {
-		t.Fatalf("users section not correctly set when invalid keys are present")
-	}
+type TestUnitManager struct {
+	placed   []string
+	enabled  []string
+	masked   []string
+	unmasked []string
+	commands []UnitAction
+	reload   bool
+}

-	var warnings string
-	catchWarn := func(f string, v ...interface{}) {
-		warnings += fmt.Sprintf(f, v...)
-	}
+type UnitAction struct {
+	unit    string
+	command string
+}

-	warnOnUnrecognizedKeys(contents, catchWarn)
+func (tum *TestUnitManager) PlaceUnit(u system.Unit) error {
+	tum.placed = append(tum.placed, u.Name)
+	return nil
+}
+func (tum *TestUnitManager) PlaceUnitDropIn(u system.Unit, d config.UnitDropIn) error {
+	tum.placed = append(tum.placed, u.Name+".d/"+d.Name)
+	return nil
+}
+func (tum *TestUnitManager) EnableUnitFile(u system.Unit) error {
+	tum.enabled = append(tum.enabled, u.Name)
+	return nil
+}
+func (tum *TestUnitManager) RunUnitCommand(u system.Unit, c string) (string, error) {
+	tum.commands = append(tum.commands, UnitAction{u.Name, c})
+	return "", nil
+}
+func (tum *TestUnitManager) DaemonReload() error {
+	tum.reload = true
+	return nil
+}
+func (tum *TestUnitManager) MaskUnit(u system.Unit) error {
+	tum.masked = append(tum.masked, u.Name)
+	return nil
+}
+func (tum *TestUnitManager) UnmaskUnit(u system.Unit) error {
+	tum.unmasked = append(tum.unmasked, u.Name)
+	return nil
+}

-	if !strings.Contains(warnings, "coreos_unknown") {
-		t.Errorf("warnings did not catch unrecognized coreos option coreos_unknown")
-	}
-	if !strings.Contains(warnings, "bare_unknown") {
-		t.Errorf("warnings did not catch unrecognized key bare_unknown")
-	}
-	if !strings.Contains(warnings, "section_unknown") {
-		t.Errorf("warnings did not catch unrecognized key section_unknown")
-	}
-	if !strings.Contains(warnings, "user_unknown") {
-		t.Errorf("warnings did not catch unrecognized user key user_unknown")
-	}
-	if !strings.Contains(warnings, "file_unknown") {
-		t.Errorf("warnings did not catch unrecognized file key file_unknown")
+type mockInterface struct {
+	name           string
+	filename       string
+	netdev         string
+	link           string
+	network        string
+	kind           string
+	modprobeParams string
+}
+
+func (i mockInterface) Name() string {
+	return i.name
+}
+
+func (i mockInterface) Filename() string {
+	return i.filename
+}
+
+func (i mockInterface) Netdev() string {
+	return i.netdev
+}
+
+func (i mockInterface) Link() string {
+	return i.link
+}
+
+func (i mockInterface) Network() string {
+	return i.network
+}
+
+func (i mockInterface) Type() string {
+	return i.kind
+}
+
+func (i mockInterface) ModprobeParams() string {
+	return i.modprobeParams
+}
+
+func TestCreateNetworkingUnits(t *testing.T) {
+	for _, tt := range []struct {
+		interfaces []network.InterfaceGenerator
+		expect     []system.Unit
+	}{
+		{nil, nil},
+		{
+			[]network.InterfaceGenerator{
+				network.InterfaceGenerator(mockInterface{filename: "test"}),
+			},
+			nil,
+		},
+		{
+			[]network.InterfaceGenerator{
+				network.InterfaceGenerator(mockInterface{filename: "test1", netdev: "test netdev"}),
+				network.InterfaceGenerator(mockInterface{filename: "test2", link: "test link"}),
+				network.InterfaceGenerator(mockInterface{filename: "test3", network: "test network"}),
+			},
+			[]system.Unit{
+				system.Unit{Unit: config.Unit{Name: "test1.netdev", Runtime: true, Content: "test netdev"}},
+				system.Unit{Unit: config.Unit{Name: "test2.link", Runtime: true, Content: "test link"}},
+				system.Unit{Unit: config.Unit{Name: "test3.network", Runtime: true, Content: "test network"}},
+			},
+		},
+		{
+			[]network.InterfaceGenerator{
+				network.InterfaceGenerator(mockInterface{filename: "test", netdev: "test netdev", link: "test link", network: "test network"}),
+			},
+			[]system.Unit{
+				system.Unit{Unit: config.Unit{Name: "test.netdev", Runtime: true, Content: "test netdev"}},
+				system.Unit{Unit: config.Unit{Name: "test.link", Runtime: true, Content: "test link"}},
+				system.Unit{Unit: config.Unit{Name: "test.network", Runtime: true, Content: "test network"}},
+			},
+		},
+	} {
+		units := createNetworkingUnits(tt.interfaces)
+		if !reflect.DeepEqual(tt.expect, units) {
+			t.Errorf("bad units (%+v): want %#v, got %#v", tt.interfaces, tt.expect, units)
+		}
 	}
 }

-// Assert that the parsing of a cloud config file "generally works"
-func TestCloudConfigEmpty(t *testing.T) {
-	cfg, err := NewCloudConfig("")
-	if err != nil {
-		t.Fatalf("Encountered unexpected error :%v", err)
+func TestProcessUnits(t *testing.T) {
+	tests := []struct {
+		units []system.Unit
+
+		result TestUnitManager
+	}{
+		{
+			units: []system.Unit{
+				system.Unit{Unit: config.Unit{
+					Name: "foo",
+					Mask: true,
+				}},
+			},
+			result: TestUnitManager{
+				masked: []string{"foo"},
+			},
+		},
+		{
+			units: []system.Unit{
+				system.Unit{Unit: config.Unit{
+					Name:    "baz.service",
+					Content: "[Service]\nExecStart=/bin/baz",
+					Command: "start",
+				}},
+				system.Unit{Unit: config.Unit{
+					Name:    "foo.network",
+					Content: "[Network]\nFoo=true",
+				}},
+				system.Unit{Unit: config.Unit{
+					Name:    "bar.network",
+					Content: "[Network]\nBar=true",
+				}},
+			},
+			result: TestUnitManager{
+				placed: []string{"baz.service", "foo.network", "bar.network"},
+				commands: []UnitAction{
+					UnitAction{"systemd-networkd.service", "restart"},
+					UnitAction{"baz.service", "start"},
+				},
+				reload: true,
+			},
+		},
+		{
+			units: []system.Unit{
+				system.Unit{Unit: config.Unit{
+					Name:    "baz.service",
+					Content: "[Service]\nExecStart=/bin/true",
+				}},
+			},
+			result: TestUnitManager{
+				placed: []string{"baz.service"},
+				reload: true,
+			},
+		},
+		{
+			units: []system.Unit{
+				system.Unit{Unit: config.Unit{
+					Name:    "locksmithd.service",
+					Runtime: true,
+				}},
+			},
+			result: TestUnitManager{
+				unmasked: []string{"locksmithd.service"},
+			},
+		},
+		{
+			units: []system.Unit{
+				system.Unit{Unit: config.Unit{
+					Name:   "woof",
+					Enable: true,
+				}},
+			},
+			result: TestUnitManager{
+				enabled: []string{"woof"},
+			},
+		},
+		{
+			units: []system.Unit{
+				system.Unit{Unit: config.Unit{
+					Name:    "hi.service",
+					Runtime: true,
+					Content: "[Service]\nExecStart=/bin/echo hi",
+					DropIns: []config.UnitDropIn{
+						{
+							Name:    "lo.conf",
+							Content: "[Service]\nExecStart=/bin/echo lo",
+						},
+						{
+							Name:    "bye.conf",
+							Content: "[Service]\nExecStart=/bin/echo bye",
+						},
+					},
+				}},
+			},
+			result: TestUnitManager{
+				placed:   []string{"hi.service", "hi.service.d/lo.conf", "hi.service.d/bye.conf"},
+				unmasked: []string{"hi.service"},
+				reload:   true,
+			},
+		},
+		{
+			units: []system.Unit{
+				system.Unit{Unit: config.Unit{
+					DropIns: []config.UnitDropIn{
+						{
+							Name:    "lo.conf",
+							Content: "[Service]\nExecStart=/bin/echo lo",
+						},
+					},
+				}},
+			},
+			result: TestUnitManager{},
+		},
+		{
+			units: []system.Unit{
+				system.Unit{Unit: config.Unit{
+					Name: "hi.service",
+					DropIns: []config.UnitDropIn{
+						{
+							Content: "[Service]\nExecStart=/bin/echo lo",
+						},
+					},
+				}},
+			},
+			result: TestUnitManager{},
+		},
+		{
+			units: []system.Unit{
+				system.Unit{Unit: config.Unit{
+					Name: "hi.service",
+					DropIns: []config.UnitDropIn{
+						{
+							Name: "lo.conf",
+						},
+					},
+				}},
+			},
+			result: TestUnitManager{},
+		},
 	}

-	keys := cfg.SSHAuthorizedKeys
-	if len(keys) != 0 {
-		t.Error("Parsed incorrect number of SSH keys")
-	}
-
-	if len(cfg.WriteFiles) != 0 {
-		t.Error("Expected zero WriteFiles")
-	}
-
-	if cfg.Hostname != "" {
-		t.Errorf("Expected hostname to be empty, got '%s'", cfg.Hostname)
-	}
-}
-
-// Assert that the parsing of a cloud config file "generally works"
-func TestCloudConfig(t *testing.T) {
-	contents := `
-coreos: 
-  etcd:
-    discovery: "https://discovery.etcd.io/827c73219eeb2fa5530027c37bf18877"
-  update:
-    reboot-strategy: reboot
-  units:
-    - name: 50-eth0.network
-      runtime: yes
-      content: '[Match]
- 
-    Name=eth47
- 
- 
-    [Network]
- 
-    Address=10.209.171.177/19
- 
-'
-  oem:
-    id: rackspace
-    name: Rackspace Cloud Servers
-    version-id: 168.0.0
-    home-url: https://www.rackspace.com/cloud/servers/
-    bug-report-url: https://github.com/coreos/coreos-overlay
-ssh_authorized_keys:
-  - foobar
-  - foobaz
-write_files:
-  - content: |
-      penny
-      elroy
-    path: /etc/dogepack.conf
-    permissions: '0644'
-    owner: root:dogepack
-hostname: trontastic
-`
-	cfg, err := NewCloudConfig(contents)
-	if err != nil {
-		t.Fatalf("Encountered unexpected error :%v", err)
-	}
-
-	keys := cfg.SSHAuthorizedKeys
-	if len(keys) != 2 {
-		t.Error("Parsed incorrect number of SSH keys")
-	} else if keys[0] != "foobar" {
-		t.Error("Expected first SSH key to be 'foobar'")
-	} else if keys[1] != "foobaz" {
-		t.Error("Expected first SSH key to be 'foobaz'")
-	}
-
-	if len(cfg.WriteFiles) != 1 {
-		t.Error("Failed to parse correct number of write_files")
-	} else {
-		wf := cfg.WriteFiles[0]
-		if wf.Content != "penny\nelroy\n" {
-			t.Errorf("WriteFile has incorrect contents '%s'", wf.Content)
-		}
-		if wf.Encoding != "" {
-			t.Errorf("WriteFile has incorrect encoding %s", wf.Encoding)
-		}
-		if perm, _ := wf.Permissions(); perm != 0644 {
-			t.Errorf("WriteFile has incorrect permissions %s", perm)
-		}
-		if wf.Path != "/etc/dogepack.conf" {
-			t.Errorf("WriteFile has incorrect path %s", wf.Path)
-		}
-		if wf.Owner != "root:dogepack" {
-			t.Errorf("WriteFile has incorrect owner %s", wf.Owner)
-		}
-	}
-
-	if len(cfg.Coreos.Units) != 1 {
-		t.Error("Failed to parse correct number of units")
-	} else {
-		u := cfg.Coreos.Units[0]
-		expect := `[Match]
-Name=eth47
-
-[Network]
-Address=10.209.171.177/19
-`
-		if u.Content != expect {
-			t.Errorf("Unit has incorrect contents '%s'.\nExpected '%s'.", u.Content, expect)
-		}
-		if u.Runtime != true {
-			t.Errorf("Unit has incorrect runtime value")
-		}
-		if u.Name != "50-eth0.network" {
-			t.Errorf("Unit has incorrect name %s", u.Name)
-		}
-		if u.Type() != "network" {
-			t.Errorf("Unit has incorrect type '%s'", u.Type())
-		}
-	}
-
-	if cfg.Coreos.OEM.ID != "rackspace" {
-		t.Errorf("Failed parsing coreos.oem. Expected ID 'rackspace', got %q.", cfg.Coreos.OEM.ID)
-	}
-
-	if cfg.Hostname != "trontastic" {
-		t.Errorf("Failed to parse hostname")
-	}
-	if cfg.Coreos.Update["reboot-strategy"] != "reboot" {
-		t.Errorf("Failed to parse locksmith strategy")
-	}
-}
-
-// Assert that our interface conversion doesn't panic
-func TestCloudConfigKeysNotList(t *testing.T) {
-	contents := `
-ssh_authorized_keys:
-  - foo: bar
-`
-	cfg, err := NewCloudConfig(contents)
-	if err != nil {
-		t.Fatalf("Encountered unexpected error: %v", err)
-	}
-
-	keys := cfg.SSHAuthorizedKeys
-	if len(keys) != 0 {
-		t.Error("Parsed incorrect number of SSH keys")
-	}
-}
-
-func TestCloudConfigSerializationHeader(t *testing.T) {
-	cfg, _ := NewCloudConfig("")
-	contents := cfg.String()
-	header := strings.SplitN(contents, "\n", 2)[0]
-	if header != "#cloud-config" {
-		t.Fatalf("Serialized config did not have expected header")
-	}
-}
-
-// TestDropInIgnored asserts that users are unable to set DropIn=True on units
-func TestDropInIgnored(t *testing.T) {
-	contents := `
-coreos:
-  units:
-    - name: test
-      dropin: true
-`
-	cfg, err := NewCloudConfig(contents)
-	if err != nil || len(cfg.Coreos.Units) != 1 {
-		t.Fatalf("Encountered unexpected error: %v", err)
-	}
-	if len(cfg.Coreos.Units) != 1 || cfg.Coreos.Units[0].Name != "test" {
-		t.Fatalf("Expected 1 unit, but got %d: %v", len(cfg.Coreos.Units), cfg.Coreos.Units)
-	}
-	if cfg.Coreos.Units[0].DropIn {
-		t.Errorf("dropin option on unit in cloud-config was not ignored!")
-	}
-}
-
-func TestCloudConfigUsers(t *testing.T) {
-	contents := `
-users:
-  - name: elroy
-    passwd: somehash
-    ssh-authorized-keys:
-      - somekey
-    gecos: arbitrary comment
-    homedir: /home/place
-    no-create-home: yes
-    primary-group: things
-    groups:
-      - ping
-      - pong
-    no-user-group: true
-    system: y
-    no-log-init: True
-`
-	cfg, err := NewCloudConfig(contents)
-	if err != nil {
-		t.Fatalf("Encountered unexpected error: %v", err)
-	}
-
-	if len(cfg.Users) != 1 {
-		t.Fatalf("Parsed %d users, expected 1", cfg.Users)
-	}
-
-	user := cfg.Users[0]
-
-	if user.Name != "elroy" {
-		t.Errorf("User name is %q, expected 'elroy'", user.Name)
-	}
-
-	if user.PasswordHash != "somehash" {
-		t.Errorf("User passwd is %q, expected 'somehash'", user.PasswordHash)
-	}
-
-	if keys := user.SSHAuthorizedKeys; len(keys) != 1 {
-		t.Errorf("Parsed %d ssh keys, expected 1", len(keys))
-	} else {
-		key := user.SSHAuthorizedKeys[0]
-		if key != "somekey" {
-			t.Errorf("User SSH key is %q, expected 'somekey'", key)
-		}
-	}
-
-	if user.GECOS != "arbitrary comment" {
-		t.Errorf("Failed to parse gecos field, got %q", user.GECOS)
-	}
-
-	if user.Homedir != "/home/place" {
-		t.Errorf("Failed to parse homedir field, got %q", user.Homedir)
-	}
-
-	if !user.NoCreateHome {
-		t.Errorf("Failed to parse no-create-home field")
-	}
-
-	if user.PrimaryGroup != "things" {
-		t.Errorf("Failed to parse primary-group field, got %q", user.PrimaryGroup)
-	}
-
-	if len(user.Groups) != 2 {
-		t.Errorf("Failed to parse 2 goups, got %d", len(user.Groups))
-	} else {
-		if user.Groups[0] != "ping" {
-			t.Errorf("First group was %q, not expected value 'ping'", user.Groups[0])
-		}
-		if user.Groups[1] != "pong" {
-			t.Errorf("First group was %q, not expected value 'pong'", user.Groups[1])
-		}
-	}
-
-	if !user.NoUserGroup {
-		t.Errorf("Failed to parse no-user-group field")
-	}
-
-	if !user.System {
-		t.Errorf("Failed to parse system field")
-	}
-
-	if !user.NoLogInit {
-		t.Errorf("Failed to parse no-log-init field")
+	for _, tt := range tests {
+		tum := &TestUnitManager{}
+		if err := processUnits(tt.units, "", tum); err != nil {
+			t.Errorf("bad error (%+v): want nil, got %s", tt.units, err)
+		}
+		if !reflect.DeepEqual(tt.result, *tum) {
+			t.Errorf("bad result (%+v): want %+v, got %+v", tt.units, tt.result, tum)
+		}
 	}
 }
--- a/initialize/env.go
+++ b/initialize/env.go
@@ -1,60 +1,116 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package initialize

 import (
+	"net"
 	"os"
 	"path"
+	"regexp"
 	"strings"
+
+	"github.com/coreos/coreos-cloudinit/config"
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/system"
 )

 const DefaultSSHKeyName = "coreos-cloudinit"

 type Environment struct {
 	root          string
+	configRoot    string
 	workspace     string
 	sshKeyName    string
 	substitutions map[string]string
 }

-func NewEnvironment(root, workspace string) *Environment {
-	substitutions := map[string]string{
-		"$public_ipv4":  os.Getenv("COREOS_PUBLIC_IPV4"),
-		"$private_ipv4": os.Getenv("COREOS_PRIVATE_IPV4"),
+// TODO(jonboulle): this is getting unwieldy, should be able to simplify the interface somehow
+func NewEnvironment(root, configRoot, workspace, sshKeyName string, metadata datasource.Metadata) *Environment {
+	firstNonNull := func(ip net.IP, env string) string {
+		if ip == nil {
+			return env
+		}
+		return ip.String()
 	}
-	return &Environment{root, workspace, DefaultSSHKeyName, substitutions}
+	substitutions := map[string]string{
+		"$public_ipv4":  firstNonNull(metadata.PublicIPv4, os.Getenv("COREOS_PUBLIC_IPV4")),
+		"$private_ipv4": firstNonNull(metadata.PrivateIPv4, os.Getenv("COREOS_PRIVATE_IPV4")),
+		"$public_ipv6":  firstNonNull(metadata.PublicIPv6, os.Getenv("COREOS_PUBLIC_IPV6")),
+		"$private_ipv6": firstNonNull(metadata.PrivateIPv6, os.Getenv("COREOS_PRIVATE_IPV6")),
+	}
+	return &Environment{root, configRoot, workspace, sshKeyName, substitutions}
 }

-func (self *Environment) Workspace() string {
-	return path.Join(self.root, self.workspace)
+func (e *Environment) Workspace() string {
+	return path.Join(e.root, e.workspace)
 }

-func (self *Environment) Root() string {
-	return self.root
+func (e *Environment) Root() string {
+	return e.root
 }

-func (self *Environment) SSHKeyName() string {
-	return self.sshKeyName
+func (e *Environment) ConfigRoot() string {
+	return e.configRoot
 }

-func (self *Environment) SetSSHKeyName(name string) {
-	self.sshKeyName = name
+func (e *Environment) SSHKeyName() string {
+	return e.sshKeyName
 }

-func (self *Environment) Apply(data string) string {
-	for key, val := range self.substitutions {
-		data = strings.Replace(data, key, val, -1)
+func (e *Environment) SetSSHKeyName(name string) {
+	e.sshKeyName = name
+}
+
+// Apply goes through the map of substitutions and replaces all instances of
+// the keys with their respective values. It supports escaping substitutions
+// with a leading '\'.
+func (e *Environment) Apply(data string) string {
+	for key, val := range e.substitutions {
+		matchKey := strings.Replace(key, `$`, `\$`, -1)
+		replKey := strings.Replace(key, `$`, `$$`, -1)
+
+		// "key" -> "val"
+		data = regexp.MustCompile(`([^\\]|^)`+matchKey).ReplaceAllString(data, `${1}`+val)
+		// "\key" -> "key"
+		data = regexp.MustCompile(`\\`+matchKey).ReplaceAllString(data, replKey)
 	}
 	return data
 }

-// normalizeSvcEnv standardizes the keys of the map (environment variables for a service)
-// by replacing any dashes with underscores and ensuring they are entirely upper case.
-// For example, "some-env" --> "SOME_ENV"
-func normalizeSvcEnv(m map[string]string) map[string]string {
-	out := make(map[string]string, len(m))
-	for key, val := range m {
-		key = strings.ToUpper(key)
-		key = strings.Replace(key, "-", "_", -1)
-		out[key] = val
+func (e *Environment) DefaultEnvironmentFile() *system.EnvFile {
+	ef := system.EnvFile{
+		File: &system.File{File: config.File{
+			Path: "/etc/environment",
+		}},
+		Vars: map[string]string{},
+	}
+	if ip, ok := e.substitutions["$public_ipv4"]; ok && len(ip) > 0 {
+		ef.Vars["COREOS_PUBLIC_IPV4"] = ip
+	}
+	if ip, ok := e.substitutions["$private_ipv4"]; ok && len(ip) > 0 {
+		ef.Vars["COREOS_PRIVATE_IPV4"] = ip
+	}
+	if ip, ok := e.substitutions["$public_ipv6"]; ok && len(ip) > 0 {
+		ef.Vars["COREOS_PUBLIC_IPV6"] = ip
+	}
+	if ip, ok := e.substitutions["$private_ipv6"]; ok && len(ip) > 0 {
+		ef.Vars["COREOS_PRIVATE_IPV6"] = ip
+	}
+	if len(ef.Vars) == 0 {
+		return nil
+	} else {
+		return &ef
 	}
-	return out
 }
--- a/initialize/env_test.go
+++ b/initialize/env_test.go
@@ -1,27 +1,148 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package initialize

 import (
+	"io/ioutil"
+	"net"
 	"os"
+	"path"
 	"testing"
+
+	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/system"
 )

 func TestEnvironmentApply(t *testing.T) {
-	os.Setenv("COREOS_PUBLIC_IPV4", "192.0.2.3")
-	os.Setenv("COREOS_PRIVATE_IPV4", "192.0.2.203")
-	env := NewEnvironment("./", "./")
-	input := `[Service]
-ExecStart=/usr/bin/echo "$public_ipv4"
-ExecStop=/usr/bin/echo $private_ipv4
-ExecStop=/usr/bin/echo $unknown
-`
-	expected := `[Service]
-ExecStart=/usr/bin/echo "192.0.2.3"
-ExecStop=/usr/bin/echo 192.0.2.203
-ExecStop=/usr/bin/echo $unknown
-`
+	os.Setenv("COREOS_PUBLIC_IPV4", "1.2.3.4")
+	os.Setenv("COREOS_PRIVATE_IPV4", "5.6.7.8")
+	os.Setenv("COREOS_PUBLIC_IPV6", "1234::")
+	os.Setenv("COREOS_PRIVATE_IPV6", "5678::")
+	for _, tt := range []struct {
+		metadata datasource.Metadata
+		input    string
+		out      string
+	}{
+		{
+			// Substituting both values directly should always take precedence
+			// over environment variables
+			datasource.Metadata{
+				PublicIPv4:  net.ParseIP("192.0.2.3"),
+				PrivateIPv4: net.ParseIP("192.0.2.203"),
+				PublicIPv6:  net.ParseIP("fe00:1234::"),
+				PrivateIPv6: net.ParseIP("fe00:5678::"),
+			},
+			`[Service]
+ExecStart=/usr/bin/echo "$public_ipv4 $public_ipv6"
+ExecStop=/usr/bin/echo $private_ipv4 $private_ipv6
+ExecStop=/usr/bin/echo $unknown`,
+			`[Service]
+ExecStart=/usr/bin/echo "192.0.2.3 fe00:1234::"
+ExecStop=/usr/bin/echo 192.0.2.203 fe00:5678::
+ExecStop=/usr/bin/echo $unknown`,
+		},
+		{
+			// Substituting one value directly while falling back with the other
+			datasource.Metadata{
+				PrivateIPv4: net.ParseIP("127.0.0.1"),
+			},
+			"$private_ipv4\n$public_ipv4",
+			"127.0.0.1\n1.2.3.4",
+		},
+		{
+			// Falling back to environment variables for both values
+			datasource.Metadata{},
+			"$private_ipv4\n$public_ipv4",
+			"5.6.7.8\n1.2.3.4",
+		},
+		{
+			// No substitutions
+			datasource.Metadata{},
+			"$private_ipv4\nfoobar",
+			"5.6.7.8\nfoobar",
+		},
+		{
+			// Escaping substitutions
+			datasource.Metadata{
+				PrivateIPv4: net.ParseIP("127.0.0.1"),
+			},
+			`\$private_ipv4
+$private_ipv4
+addr: \$private_ipv4
+\\$private_ipv4`,
+			`$private_ipv4
+127.0.0.1
+addr: $private_ipv4
+\$private_ipv4`,
+		},
+		{
+			// No substitutions with escaping
+			datasource.Metadata{},
+			"\\$test\n$test",
+			"\\$test\n$test",
+		},
+	} {

-	output := env.Apply(input)
-	if output != expected {
-		t.Fatalf("Environment incorrectly applied.\nOutput:\n%s\nExpected:\n%s", output, expected)
+		env := NewEnvironment("./", "./", "./", "", tt.metadata)
+		got := env.Apply(tt.input)
+		if got != tt.out {
+			t.Fatalf("Environment incorrectly applied.\ngot:\n%s\nwant:\n%s", got, tt.out)
+		}
+	}
+}
+
+func TestEnvironmentFile(t *testing.T) {
+	metadata := datasource.Metadata{
+		PublicIPv4:  net.ParseIP("1.2.3.4"),
+		PrivateIPv4: net.ParseIP("5.6.7.8"),
+		PublicIPv6:  net.ParseIP("1234::"),
+		PrivateIPv6: net.ParseIP("5678::"),
+	}
+	expect := "COREOS_PRIVATE_IPV4=5.6.7.8\nCOREOS_PRIVATE_IPV6=5678::\nCOREOS_PUBLIC_IPV4=1.2.3.4\nCOREOS_PUBLIC_IPV6=1234::\n"
+
+	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
+	if err != nil {
+		t.Fatalf("Unable to create tempdir: %v", err)
+	}
+	defer os.RemoveAll(dir)
+
+	env := NewEnvironment("./", "./", "./", "", metadata)
+	ef := env.DefaultEnvironmentFile()
+	err = system.WriteEnvFile(ef, dir)
+	if err != nil {
+		t.Fatalf("WriteEnvFile failed: %v", err)
+	}
+
+	fullPath := path.Join(dir, "etc", "environment")
+	contents, err := ioutil.ReadFile(fullPath)
+	if err != nil {
+		t.Fatalf("Unable to read expected file: %v", err)
+	}
+
+	if string(contents) != expect {
+		t.Fatalf("File has incorrect contents: %q", contents)
+	}
+}
+
+func TestEnvironmentFileNil(t *testing.T) {
+	os.Clearenv()
+	metadata := datasource.Metadata{}
+
+	env := NewEnvironment("./", "./", "./", "", metadata)
+	ef := env.DefaultEnvironmentFile()
+	if ef != nil {
+		t.Fatalf("Environment file not nil: %v", ef)
 	}
 }
--- a/initialize/etcd.go
+++ b/initialize/etcd.go
@@ -1,55 +0,0 @@
-package initialize
-
-import (
-	"errors"
-	"fmt"
-
-	"github.com/coreos/coreos-cloudinit/system"
-)
-
-type EtcdEnvironment map[string]string
-
-func (ee EtcdEnvironment) String() (out string) {
-	norm := normalizeSvcEnv(ee)
-
-	if val, ok := norm["DISCOVERY_URL"]; ok {
-		delete(norm, "DISCOVERY_URL")
-		if _, ok := norm["DISCOVERY"]; !ok {
-			norm["DISCOVERY"] = val
-		}
-	}
-
-	out += "[Service]\n"
-
-	for key, val := range norm {
-		out += fmt.Sprintf("Environment=\"ETCD_%s=%s\"\n", key, val)
-	}
-
-	return
-}
-
-// Units creates a Unit file drop-in for etcd, using any configured
-// options and adding a default MachineID if unset.
-func (ee EtcdEnvironment) Units(root string) ([]system.Unit, error) {
-	if ee == nil {
-		return nil, nil
-	}
-
-	if _, ok := ee["name"]; !ok {
-		if machineID := system.MachineID(root); machineID != "" {
-			ee["name"] = machineID
-		} else if hostname, err := system.Hostname(); err == nil {
-			ee["name"] = hostname
-		} else {
-			return nil, errors.New("Unable to determine default etcd name")
-		}
-	}
-
-	etcd := system.Unit{
-		Name:    "etcd.service",
-		Runtime: true,
-		DropIn:  true,
-		Content: ee.String(),
-	}
-	return []system.Unit{etcd}, nil
-}
--- a/initialize/etcd_test.go
+++ b/initialize/etcd_test.go
@@ -1,168 +0,0 @@
-package initialize
-
-import (
-	"io/ioutil"
-	"os"
-	"path"
-	"testing"
-
-	"github.com/coreos/coreos-cloudinit/system"
-)
-
-func TestEtcdEnvironment(t *testing.T) {
-	cfg := make(EtcdEnvironment, 0)
-	cfg["discovery"] = "http://disco.example.com/foobar"
-	cfg["peer-bind-addr"] = "127.0.0.1:7002"
-
-	env := cfg.String()
-	expect := `[Service]
-Environment="ETCD_DISCOVERY=http://disco.example.com/foobar"
-Environment="ETCD_PEER_BIND_ADDR=127.0.0.1:7002"
-`
-
-	if env != expect {
-		t.Errorf("Generated environment:\n%s\nExpected environment:\n%s", env, expect)
-	}
-}
-
-func TestEtcdEnvironmentDiscoveryURLTranslated(t *testing.T) {
-	cfg := make(EtcdEnvironment, 0)
-	cfg["discovery_url"] = "http://disco.example.com/foobar"
-	cfg["peer-bind-addr"] = "127.0.0.1:7002"
-
-	env := cfg.String()
-	expect := `[Service]
-Environment="ETCD_DISCOVERY=http://disco.example.com/foobar"
-Environment="ETCD_PEER_BIND_ADDR=127.0.0.1:7002"
-`
-
-	if env != expect {
-		t.Errorf("Generated environment:\n%s\nExpected environment:\n%s", env, expect)
-	}
-}
-
-func TestEtcdEnvironmentDiscoveryOverridesDiscoveryURL(t *testing.T) {
-	cfg := make(EtcdEnvironment, 0)
-	cfg["discovery_url"] = "ping"
-	cfg["discovery"] = "pong"
-	cfg["peer-bind-addr"] = "127.0.0.1:7002"
-
-	env := cfg.String()
-	expect := `[Service]
-Environment="ETCD_DISCOVERY=pong"
-Environment="ETCD_PEER_BIND_ADDR=127.0.0.1:7002"
-`
-
-	if env != expect {
-		t.Errorf("Generated environment:\n%s\nExpected environment:\n%s", env, expect)
-	}
-}
-
-func TestEtcdEnvironmentWrittenToDisk(t *testing.T) {
-	ee := EtcdEnvironment{
-		"name":           "node001",
-		"discovery":      "http://disco.example.com/foobar",
-		"peer-bind-addr": "127.0.0.1:7002",
-	}
-	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
-	if err != nil {
-		t.Fatalf("Unable to create tempdir: %v", err)
-	}
-	defer os.RemoveAll(dir)
-
-	uu, err := ee.Units(dir)
-	if err != nil {
-		t.Fatalf("Generating etcd unit failed: %v", err)
-	}
-	if len(uu) != 1 {
-		t.Fatalf("Expected 1 unit to be returned, got %d", len(uu))
-	}
-	u := uu[0]
-
-	dst := u.Destination(dir)
-	os.Stderr.WriteString("writing to " + dir + "\n")
-	if err := system.PlaceUnit(&u, dst); err != nil {
-		t.Fatalf("Writing of EtcdEnvironment failed: %v", err)
-	}
-
-	fullPath := path.Join(dir, "run", "systemd", "system", "etcd.service.d", "20-cloudinit.conf")
-
-	fi, err := os.Stat(fullPath)
-	if err != nil {
-		t.Fatalf("Unable to stat file: %v", err)
-	}
-
-	if fi.Mode() != os.FileMode(0644) {
-		t.Errorf("File has incorrect mode: %v", fi.Mode())
-	}
-
-	contents, err := ioutil.ReadFile(fullPath)
-	if err != nil {
-		t.Fatalf("Unable to read expected file: %v", err)
-	}
-
-	expect := `[Service]
-Environment="ETCD_NAME=node001"
-Environment="ETCD_DISCOVERY=http://disco.example.com/foobar"
-Environment="ETCD_PEER_BIND_ADDR=127.0.0.1:7002"
-`
-	if string(contents) != expect {
-		t.Fatalf("File has incorrect contents")
-	}
-}
-
-func TestEtcdEnvironmentWrittenToDiskDefaultToMachineID(t *testing.T) {
-	ee := EtcdEnvironment{}
-	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
-	if err != nil {
-		t.Fatalf("Unable to create tempdir: %v", err)
-	}
-	defer os.RemoveAll(dir)
-
-	os.Mkdir(path.Join(dir, "etc"), os.FileMode(0755))
-	err = ioutil.WriteFile(path.Join(dir, "etc", "machine-id"), []byte("node007"), os.FileMode(0444))
-	if err != nil {
-		t.Fatalf("Failed writing out /etc/machine-id: %v", err)
-	}
-
-	uu, err := ee.Units(dir)
-	if err != nil {
-		t.Fatalf("Generating etcd unit failed: %v", err)
-	}
-	if len(uu) == 0 {
-		t.Fatalf("Returned empty etcd units unexpectedly")
-	}
-	u := uu[0]
-
-	dst := u.Destination(dir)
-	os.Stderr.WriteString("writing to " + dir + "\n")
-	if err := system.PlaceUnit(&u, dst); err != nil {
-		t.Fatalf("Writing of EtcdEnvironment failed: %v", err)
-	}
-
-	fullPath := path.Join(dir, "run", "systemd", "system", "etcd.service.d", "20-cloudinit.conf")
-
-	contents, err := ioutil.ReadFile(fullPath)
-	if err != nil {
-		t.Fatalf("Unable to read expected file: %v", err)
-	}
-
-	expect := `[Service]
-Environment="ETCD_NAME=node007"
-`
-	if string(contents) != expect {
-		t.Fatalf("File has incorrect contents")
-	}
-}
-
-func TestEtcdEnvironmentWhenNil(t *testing.T) {
-	// EtcdEnvironment will be a nil map if it wasn't in the yaml
-	var ee EtcdEnvironment
-	if ee != nil {
-		t.Fatalf("EtcdEnvironment is not nil")
-	}
-	uu, err := ee.Units("")
-	if len(uu) != 0 || err != nil {
-		t.Fatalf("Units returned value for nil input")
-	}
-}
--- a/initialize/fleet.go
+++ b/initialize/fleet.go
@@ -1,35 +0,0 @@
-package initialize
-
-import (
-	"fmt"
-
-	"github.com/coreos/coreos-cloudinit/system"
-)
-
-type FleetEnvironment map[string]string
-
-func (fe FleetEnvironment) String() (out string) {
-	norm := normalizeSvcEnv(fe)
-	out += "[Service]\n"
-
-	for key, val := range norm {
-		out += fmt.Sprintf("Environment=\"FLEET_%s=%s\"\n", key, val)
-	}
-
-	return
-}
-
-// Units generates a Unit file drop-in for fleet, if any fleet options were
-// configured in cloud-config
-func (fe FleetEnvironment) Units(root string) ([]system.Unit, error) {
-	if len(fe) < 1 {
-		return nil, nil
-	}
-	fleet := system.Unit{
-		Name:    "fleet.service",
-		Runtime: true,
-		DropIn:  true,
-		Content: fe.String(),
-	}
-	return []system.Unit{fleet}, nil
-}
--- a/initialize/fleet_test.go
+++ b/initialize/fleet_test.go
@@ -1,43 +0,0 @@
-package initialize
-
-import "testing"
-
-func TestFleetEnvironment(t *testing.T) {
-	cfg := make(FleetEnvironment, 0)
-	cfg["public-ip"] = "12.34.56.78"
-
-	env := cfg.String()
-
-	expect := `[Service]
-Environment="FLEET_PUBLIC_IP=12.34.56.78"
-`
-
-	if env != expect {
-		t.Errorf("Generated environment:\n%s\nExpected environment:\n%s", env, expect)
-	}
-}
-
-func TestFleetUnit(t *testing.T) {
-	cfg := make(FleetEnvironment, 0)
-	uu, err := cfg.Units("/")
-	if len(uu) != 0 {
-		t.Errorf("unexpectedly generated unit with empty FleetEnvironment")
-	}
-
-	cfg["public-ip"] = "12.34.56.78"
-
-	uu, err = cfg.Units("/")
-	if err != nil {
-		t.Errorf("error generating fleet unit: %v", err)
-	}
-	if len(uu) != 1 {
-		t.Fatalf("expected 1 unit generated, got %d", len(uu))
-	}
-	u := uu[0]
-	if !u.Runtime {
-		t.Errorf("bad Runtime for generated fleet unit!")
-	}
-	if !u.DropIn {
-		t.Errorf("bad DropIn for generated fleet unit!")
-	}
-}
--- a/initialize/github.go
+++ b/initialize/github.go
@@ -1,3 +1,17 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package initialize

 import (
--- a/initialize/github_test.go
+++ b/initialize/github_test.go
@@ -1,32 +0,0 @@
-package initialize
-
-import (
-	"testing"
-)
-
-func TestCloudConfigUsersGithubUser(t *testing.T) {
-
-	contents := `
-users:
-  - name: elroy
-    coreos-ssh-import-github: bcwaldon
-`
-	cfg, err := NewCloudConfig(contents)
-	if err != nil {
-		t.Fatalf("Encountered unexpected error: %v", err)
-	}
-
-	if len(cfg.Users) != 1 {
-		t.Fatalf("Parsed %d users, expected 1", cfg.Users)
-	}
-
-	user := cfg.Users[0]
-
-	if user.Name != "elroy" {
-		t.Errorf("User name is %q, expected 'elroy'", user.Name)
-	}
-
-	if user.SSHImportGithubUser != "bcwaldon" {
-		t.Errorf("github user is %q, expected 'bcwaldon'", user.SSHImportGithubUser)
-	}
-}
--- a/initialize/manage_etc_hosts.go
+++ b/initialize/manage_etc_hosts.go
@@ -1,46 +0,0 @@
-package initialize
-
-import (
-	"errors"
-	"fmt"
-	"os"
-	"path"
-
-	"github.com/coreos/coreos-cloudinit/system"
-)
-
-const DefaultIpv4Address = "127.0.0.1"
-
-type EtcHosts string
-
-func (eh EtcHosts) generateEtcHosts() (out string, err error) {
-	if eh != "localhost" {
-		return "", errors.New("Invalid option to manage_etc_hosts")
-	}
-
-	// use the operating system hostname
-	hostname, err := os.Hostname()
-	if err != nil {
-		return "", err
-	}
-
-	return fmt.Sprintf("%s %s\n", DefaultIpv4Address, hostname), nil
-
-}
-
-func (eh EtcHosts) File(root string) (*system.File, error) {
-	if eh == "" {
-		return nil, nil
-	}
-
-	etcHosts, err := eh.generateEtcHosts()
-	if err != nil {
-		return nil, err
-	}
-
-	return &system.File{
-		Path:               path.Join("etc", "hosts"),
-		RawFilePermissions: "0644",
-		Content:            etcHosts,
-	}, nil
-}
--- a/initialize/manage_etc_hosts_test.go
+++ b/initialize/manage_etc_hosts_test.go
@@ -1,83 +0,0 @@
-package initialize
-
-import (
-	"fmt"
-	"io/ioutil"
-	"os"
-	"path"
-	"testing"
-
-	"github.com/coreos/coreos-cloudinit/system"
-)
-
-func TestCloudConfigManageEtcHosts(t *testing.T) {
-	contents := `
-manage_etc_hosts: localhost
-`
-	cfg, err := NewCloudConfig(contents)
-	if err != nil {
-		t.Fatalf("Encountered unexpected error: %v", err)
-	}
-
-	manageEtcHosts := cfg.ManageEtcHosts
-
-	if manageEtcHosts != "localhost" {
-		t.Errorf("ManageEtcHosts value is %q, expected 'localhost'", manageEtcHosts)
-	}
-}
-
-func TestManageEtcHostsInvalidValue(t *testing.T) {
-	eh := EtcHosts("invalid")
-	if f, err := eh.File(""); err == nil || f != nil {
-		t.Fatalf("EtcHosts File succeeded with invalid value!")
-	}
-}
-
-func TestEtcHostsWrittenToDisk(t *testing.T) {
-	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
-	if err != nil {
-		t.Fatalf("Unable to create tempdir: %v", err)
-	}
-	defer os.RemoveAll(dir)
-
-	eh := EtcHosts("localhost")
-
-	f, err := eh.File(dir)
-	if err != nil {
-		t.Fatalf("Error calling File on EtcHosts: %v", err)
-	}
-	if f == nil {
-		t.Fatalf("manageEtcHosts returned nil file unexpectedly")
-	}
-
-	if _, err := system.WriteFile(f, dir); err != nil {
-		t.Fatalf("Error writing EtcHosts: %v", err)
-	}
-
-	fullPath := path.Join(dir, "etc", "hosts")
-
-	fi, err := os.Stat(fullPath)
-	if err != nil {
-		t.Fatalf("Unable to stat file: %v", err)
-	}
-
-	if fi.Mode() != os.FileMode(0644) {
-		t.Errorf("File has incorrect mode: %v", fi.Mode())
-	}
-
-	contents, err := ioutil.ReadFile(fullPath)
-	if err != nil {
-		t.Fatalf("Unable to read expected file: %v", err)
-	}
-
-	hostname, err := os.Hostname()
-	if err != nil {
-		t.Fatalf("Unable to read OS hostname: %v", err)
-	}
-
-	expect := fmt.Sprintf("%s %s\n", DefaultIpv4Address, hostname)
-
-	if string(contents) != expect {
-		t.Fatalf("File has incorrect contents")
-	}
-}
--- a/initialize/oem.go
+++ b/initialize/oem.go
@@ -1,41 +0,0 @@
-package initialize
-
-import (
-	"fmt"
-	"path"
-	"strings"
-
-	"github.com/coreos/coreos-cloudinit/system"
-)
-
-type OEMRelease struct {
-	ID           string `yaml:"id"`
-	Name         string `yaml:"name"`
-	VersionID    string `yaml:"version-id"`
-	HomeURL      string `yaml:"home-url"`
-	BugReportURL string `yaml:"bug-report-url"`
-}
-
-func (oem OEMRelease) String() string {
-	fields := []string{
-		fmt.Sprintf("ID=%s", oem.ID),
-		fmt.Sprintf("VERSION_ID=%s", oem.VersionID),
-		fmt.Sprintf("NAME=%q", oem.Name),
-		fmt.Sprintf("HOME_URL=%q", oem.HomeURL),
-		fmt.Sprintf("BUG_REPORT_URL=%q", oem.BugReportURL),
-	}
-
-	return strings.Join(fields, "\n") + "\n"
-}
-
-func (oem OEMRelease) File(root string) (*system.File, error) {
-	if oem.ID == "" {
-		return nil, nil
-	}
-
-	return &system.File{
-		Path:               path.Join("etc", "oem-release"),
-		RawFilePermissions: "0644",
-		Content:            oem.String(),
-	}, nil
-}
--- a/initialize/oem_test.go
+++ b/initialize/oem_test.go
@@ -1,63 +0,0 @@
-package initialize
-
-import (
-	"io/ioutil"
-	"os"
-	"path"
-	"testing"
-
-	"github.com/coreos/coreos-cloudinit/system"
-)
-
-func TestOEMReleaseWrittenToDisk(t *testing.T) {
-	oem := OEMRelease{
-		ID:           "rackspace",
-		Name:         "Rackspace Cloud Servers",
-		VersionID:    "168.0.0",
-		HomeURL:      "https://www.rackspace.com/cloud/servers/",
-		BugReportURL: "https://github.com/coreos/coreos-overlay",
-	}
-	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
-	if err != nil {
-		t.Fatalf("Unable to create tempdir: %v", err)
-	}
-	defer os.RemoveAll(dir)
-
-	f, err := oem.File(dir)
-	if err != nil {
-		t.Fatalf("Processing of OEMRelease failed: %v", err)
-	}
-	if f == nil {
-		t.Fatalf("OEMRelease returned nil file unexpectedly")
-	}
-
-	if _, err := system.WriteFile(f, dir); err != nil {
-		t.Fatalf("Writing of OEMRelease failed: %v", err)
-	}
-
-	fullPath := path.Join(dir, "etc", "oem-release")
-
-	fi, err := os.Stat(fullPath)
-	if err != nil {
-		t.Fatalf("Unable to stat file: %v", err)
-	}
-
-	if fi.Mode() != os.FileMode(0644) {
-		t.Errorf("File has incorrect mode: %v", fi.Mode())
-	}
-
-	contents, err := ioutil.ReadFile(fullPath)
-	if err != nil {
-		t.Fatalf("Unable to read expected file: %v", err)
-	}
-
-	expect := `ID=rackspace
-VERSION_ID=168.0.0
-NAME="Rackspace Cloud Servers"
-HOME_URL="https://www.rackspace.com/cloud/servers/"
-BUG_REPORT_URL="https://github.com/coreos/coreos-overlay"
-`
-	if string(contents) != expect {
-		t.Fatalf("File has incorrect contents")
-	}
-}
--- a/initialize/ssh_keys.go
+++ b/initialize/ssh_keys.go
@@ -1,3 +1,17 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package initialize

 import (
@@ -25,7 +39,7 @@ func SSHImportKeysFromURL(system_user string, url string) error {

 func fetchUserKeys(url string) ([]string, error) {
 	client := pkg.NewHttpClient()
-	data, err := client.Get(url)
+	data, err := client.GetRetry(url)
 	if err != nil {
 		return nil, err
 	}
--- a/initialize/ssh_keys_test.go
+++ b/initialize/ssh_keys_test.go
@@ -1,3 +1,17 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package initialize

 import (
@@ -39,31 +53,4 @@ func TestCloudConfigUsersUrlMarshal(t *testing.T) {
 	if keys[2] != expected {
 		t.Fatalf("expected %s, got %s", expected, keys[2])
 	}
-
-}
-func TestCloudConfigUsersSSHImportURL(t *testing.T) {
-
-	contents := `
-users:
-  - name: elroy
-    coreos-ssh-import-url: https://token:x-auth-token@github.enterprise.com/api/v3/polvi/keys
-`
-	cfg, err := NewCloudConfig(contents)
-	if err != nil {
-		t.Fatalf("Encountered unexpected error: %v", err)
-	}
-
-	if len(cfg.Users) != 1 {
-		t.Fatalf("Parsed %d users, expected 1", cfg.Users)
-	}
-
-	user := cfg.Users[0]
-
-	if user.Name != "elroy" {
-		t.Errorf("User name is %q, expected 'elroy'", user.Name)
-	}
-
-	if user.SSHImportURL != "https://token:x-auth-token@github.enterprise.com/api/v3/polvi/keys" {
-		t.Errorf("ssh import url is %q, expected 'https://token:x-auth-token@github.enterprise.com/api/v3/polvi/keys'", user.SSHImportURL)
-	}
 }
--- a/Show More
+++ b/Show More