Reviewers: mp+202974_code.launchpad.net,

Message:
Please take a look.

Description:
Auto start for lxc containers

Auto start for lxc containers should now work on Trusty. Symlink is
created if /etc/lxc/auto exists, otherwise auto start is set to true in
lxc config.

https://code.launchpad.net/~waigani/juju-core/lxc-trusty-autostart/+merge/202974

(do not edit description out of merge proposal)


Please review this at https://codereview.appspot.com/56370043/

Affected files (+48, -6 lines):
   A [revision details]
   M container/lxc/lxc.go
   M container/lxc/lxc_test.go
   A container/lxc/restart.go


Index: [revision details]
=== added file '[revision details]'
--- [revision details]	2012-01-01 00:00:00 +0000
+++ [revision details]	2012-01-01 00:00:00 +0000
@@ -0,0 +1,2 @@
+Old revision: tarmac-20140124005805-5wkfrpv3q7zaknxv
+New revision: <email address hidden>

Index: container/lxc/lxc.go
=== modified file 'container/lxc/lxc.go'
--- container/lxc/lxc.go	2013-12-04 02:37:05 +0000
+++ container/lxc/lxc.go	2014-01-24 01:19:25 +0000
@@ -109,12 +109,14 @@
  		return nil, nil, err
  	}
  	logger.Tracef("lxc container created")
-	// Now symlink the config file into the restart directory.
-	containerConfigFile := filepath.Join(LxcContainerDir, name, "config")
-	if err := os.Symlink(containerConfigFile, restartSymlink(name)); err !=  
nil {
-		return nil, nil, err
+	// Now symlink the config file into the restart directory, if it exists
+	if restartDirExists() {
+		containerConfigFile := filepath.Join(LxcContainerDir, name, "config")
+		if err := os.Symlink(containerConfigFile, restartSymlink(name)); err !=  
nil {
+			return nil, nil, err
+		}
+		logger.Tracef("auto-restart link created")
  	}
-	logger.Tracef("auto-restart link created")

  	// Start the lxc container with the appropriate settings for grabbing the
  	// console output and a log file.
@@ -198,7 +200,12 @@
  `

  func networkConfigTemplate(networkType, networkLink string) string {
-	return fmt.Sprintf(networkTemplate, networkType, networkLink)
+	networkConfig := fmt.Sprintf(networkTemplate, networkType, networkLink)
+	if !restartDirExists() {
+		networkConfig += "lxc.start.auto = 1\n"
+		logger.Tracef("Setting auto start to true in lxc config.")
+	}
+	return networkConfig
  }

  func generateNetworkConfig(network *container.NetworkConfig) string {


Index: container/lxc/lxc_test.go
=== modified file 'container/lxc/lxc_test.go'
--- container/lxc/lxc_test.go	2013-12-16 07:20:01 +0000
+++ container/lxc/lxc_test.go	2014-01-24 01:19:25 +0000
@@ -186,6 +186,25 @@
  	c.Assert(autostartLink, jc.IsSymlink)
  }

+func (s *LxcSuite) TestStartContainerNoRestartDir(c *gc.C) {
+	err := os.Remove(s.RestartDir)
+	c.Assert(err, gc.IsNil)
+
+	manager := lxc.NewContainerManager(container.ManagerConfig{})
+	instance := containertesting.StartContainer(c, manager, "1/lxc/0")
+	autostartLink := lxc.RestartSymlink(string(instance.Id()))
+
+	config := lxc.NetworkConfigTemplate("foo", "bar")
+	expected := `
+lxc.network.type = foo
+lxc.network.link = bar
+lxc.network.flags = up
+lxc.start.auto = 1
+`
+	c.Assert(config, gc.Equals, expected)
+	c.Assert(autostartLink, jc.DoesNotExist)
+}
+
  func (s *LxcSuite) TestStopContainerRemovesAutostartLink(c *gc.C) {
  	manager := lxc.NewContainerManager(container.ManagerConfig{})
  	instance := containertesting.StartContainer(c, manager, "1/lxc/0")


Index: container/lxc/restart.go
=== added file 'container/lxc/restart.go'
--- container/lxc/restart.go	1970-01-01 00:00:00 +0000
+++ container/lxc/restart.go	2014-01-24 01:19:25 +0000
@@ -0,0 +1,14 @@
+package lxc
+
+import (
+	"os"
+)
+
+func restartDirExists() bool {
+	if _, err := os.Stat(LxcRestartDir); err != nil {
+		if os.IsNotExist(err) {
+			return false
+		}
+	}
+	return true
+}