Merge pull request #46 from bcwaldon/doc-field-sub
doc(fields): Document field substitution
This commit is contained in:
commit
81e4f1f896
@ -11,9 +11,7 @@ Only a subset of [cloud-config functionality][cloud-config] is implemented. A se
|
||||
### coreos.etcd
|
||||
|
||||
The `coreos.etcd.*` options are translated to a partial systemd unit acting as an etcd configuration file.
|
||||
`coreos-cloudinit` will also replace the strings `$private_ipv4` and `$public_ipv4` with the values generated by CoreOS based on a given provider.
|
||||
|
||||
For example, the following cloud-config document...
|
||||
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...
|
||||
|
||||
```
|
||||
#cloud-config
|
||||
|
35
README.md
35
README.md
@ -33,7 +33,6 @@ write_files:
|
||||
nameserver 192.0.2.3
|
||||
```
|
||||
|
||||
|
||||
## Executing a Script
|
||||
|
||||
coreos-cloudinit supports executing user-data as a script instead of parsing it as a cloud-config document.
|
||||
@ -44,3 +43,37 @@ Make sure the first line of your user-data is a shebang and coreos-cloudinit wil
|
||||
|
||||
echo 'Hello, world!'
|
||||
```
|
||||
|
||||
## user-data Field Substitution
|
||||
|
||||
coreos-cloudinit will replace the following set of tokens in your user-data with system-generated values.
|
||||
|
||||
| Token | Description |
|
||||
| ------------- | ----------- |
|
||||
| $public_ipv4 | Public IPv4 address of machine |
|
||||
| $private_ipv4 | Private IPv4 address of machine |
|
||||
|
||||
These values are determined by CoreOS based on the given provider on which your machine is running.
|
||||
Read more about provider-specific functionality in the [CoreOS OEM documentation][oem-doc].
|
||||
|
||||
[oem-doc]: https://coreos.com/docs/sdk-distributors/distributors/notes-for-distributors/
|
||||
|
||||
For example, submitting the following user-data...
|
||||
|
||||
```
|
||||
#cloud-config
|
||||
coreos:
|
||||
etcd:
|
||||
addr: $public_ipv4:4001
|
||||
peer-addr: $private_ipv4:7001
|
||||
```
|
||||
|
||||
...will result in this cloud-config document being executed:
|
||||
|
||||
```
|
||||
#cloud-config
|
||||
coreos:
|
||||
etcd:
|
||||
addr: 203.0.113.29:4001
|
||||
peer-addr: 192.0.2.13:7001
|
||||
```
|
Loading…
Reference in New Issue
Block a user