Enable configuration of locksmithd

Documentation/cloud-config.md

@@ -119,6 +119,30 @@ For complete list of flannel configuraion parameters, see the [flannel documenta
 
 [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: example.com:4001
+```
+
+...will generate a systemd unit drop-in like so:
+
+```
+[Service]
+Environment="LOCKSMITHD_ENDPOINT=example.com:4001"
+```
+
+For the complete list of locksmith configuraion parameters, see the [locksmith documentation][locksmith-readme].
+
+[locksmith-readme]: https://github.com/coreos/locksmith/blob/master/README.md
+
 #### update
 
 The `coreos.update.*` parameters manipulate settings related to how CoreOS instances are updated.

config/config.go

@@ -33,6 +33,7 @@ type CloudConfig struct {
 		Etcd      Etcd      `yaml:"etcd"`
 		Flannel   Flannel   `yaml:"flannel"`
 		Fleet     Fleet     `yaml:"fleet"`
+		Locksmith Locksmith `yaml:"locksmith"`
 		OEM       OEM       `yaml:"oem"`
 		Update    Update    `yaml:"update"`
 		Units     []Unit    `yaml:"units"`

config/locksmith.go

@@ -0,0 +1,8 @@
+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"`
+}

initialize/config.go

@@ -131,6 +131,7 @@ func Apply(cfg config.CloudConfig, env *Environment) error {
 	for _, ccu := range []CloudConfigUnit{
 		system.Etcd{Etcd: cfg.Coreos.Etcd},
 		system.Fleet{Fleet: cfg.Coreos.Fleet},
+		system.Locksmith{Locksmith: cfg.Coreos.Locksmith},
 		system.Flannel{Flannel: cfg.Coreos.Flannel},
 		system.Update{Update: cfg.Coreos.Update, ReadConfig: system.DefaultReadConfig},
 	} {

system/locksmith.go

@@ -0,0 +1,39 @@
+/*
+   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 system
+
+import (
+	"github.com/coreos/coreos-cloudinit/config"
+)
+
+// Locksmith is a top-level structure which embeds its underlying configuration,
+// config.Locksmith, and provides the system-specific Unit().
+type Locksmith struct {
+	config.Locksmith
+}
+
+// Units creates a Unit file drop-in for etcd, using any configured options.
+func (ee Locksmith) Units() []Unit {
+	return []Unit{{config.Unit{
+		Name:    "locksmithd.service",
+		Runtime: true,
+		DropIns: []config.UnitDropIn{{
+			Name:    "20-cloudinit.conf",
+			Content: serviceContents(ee.Locksmith),
+		}},
+	}}}
+}

system/locksmith_test.go

@@ -0,0 +1,60 @@
+/*
+   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 system
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/config"
+)
+
+func TestLocksmithUnits(t *testing.T) {
+	for _, tt := range []struct {
+		config config.Locksmith
+		units  []Unit
+	}{
+		{
+			config.Locksmith{},
+			[]Unit{{config.Unit{
+				Name:    "locksmithd.service",
+				Runtime: true,
+				DropIns: []config.UnitDropIn{{Name: "20-cloudinit.conf"}},
+			}}},
+		},
+		{
+			config.Locksmith{
+				Endpoint: "12.34.56.78:4001",
+			},
+			[]Unit{{config.Unit{
+				Name:    "locksmithd.service",
+				Runtime: true,
+				DropIns: []config.UnitDropIn{{
+					Name: "20-cloudinit.conf",
+					Content: `[Service]
+Environment="LOCKSMITHD_ENDPOINT=12.34.56.78:4001"
+`,
+				}},
+			}}},
+		},
+	} {
+		units := Locksmith{tt.config}.Units()
+		if !reflect.DeepEqual(units, tt.units) {
+			t.Errorf("bad units (%+v): want %#v, got %#v", tt.config, tt.units, units)
+		}
+	}
+}