Merge lp:~thumper/juju-core/auto-restart-containers into lp:~go-bot/juju-core/trunk

[Tim Penhey]

Add the autostart symlink for containers.

In order for containers to autostart, there needs to be
a symlink in /etc/lxc/auto called CN.conf where CN is
the container name, which points to the config file for
the container, which is by default /var/lib/lxc/CN/config.

https://codereview.appspot.com/11491043/

Add the autostart symlink for containers.

In order for containers to autostart, there needs to be
a symlink in /etc/lxc/auto called CN.conf where CN is
the container name, which points to the config file for
the container, which is by default /var/lib/lxc/CN/config.

https://codereview.appspot.com/11491043/

[Tim Penhey (thumper)]

Reviewers: mp+175435_code.launchpad.net,

Message:
Please take a look.

Description:
Add the autostart symlink for containers.

In order for containers to autostart, there needs to be
a symlink in /etc/lxc/auto called CN.conf where CN is
the container name, which points to the config file for
the container, which is by default /var/lib/lxc/CN/config.

https://code.launchpad.net/~thumper/juju-core/auto-restart-containers/+merge/175435

Requires:
https://code.launchpad.net/~thumper/juju-core/test-import-fix/+merge/175430

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/11491043/

Affected files:
   A [revision details]
   M container/lxc/lxc.go
   M container/lxc/lxc_test.go
   M container/lxc/test.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: <email address hidden>
+New revision: <email address hidden>

Index: container/lxc/lxc.go
=== modified file 'container/lxc/lxc.go'
--- container/lxc/lxc.go 2013-07-15 01:16:52 +0000
+++ container/lxc/lxc.go 2013-07-17 23:38:15 +0000
@@ -28,6 +28,7 @@
   containerDir = "/var/lib/juju/containers"
   removedContainerDir = "/var/lib/juju/removed-containers"
   lxcContainerDir = "/var/lib/lxc"
+ lxcRestartDir = "/etc/lxc/auto"
   lxcObjectFactory = golxc.Factory()
  )

@@ -125,6 +126,13 @@
    return nil, err
   }
   logger.Tracef("lxc container created")
+ // Now symlink the config file into the restart directory.
+ containerConfigFile := filepath.Join(lxcContainerDir, name, "config")
+ linkLocation := filepath.Join(lxcRestartDir, name+".conf")
+ if err := os.Symlink(containerConfigFile, linkLocation); err != nil {
+ return nil, err
+ }
+ logger.Tracef("auto-restart link created")

   // Start the lxc container with the appropriate settings for grabbing the
   // console output and a log file.
@@ -154,6 +162,13 @@
    logger.Errorf("failed to destroy lxc container: %v", err)
    return err
   }
+ // Remove the autostart symlink
+ linkLocation := filepath.Join(lxcRestartDir, name+".conf")
+ if err := os.Remove(linkLocation); err != nil {
+ return err
+ }
+ logger.Tracef("auto-restart link removed")
+
   // Move the directory.
   logger.Tracef("create old container dir: %s", removedContainerDir)
   if err := os.MkdirAll(removedContainerDir, 0755); err != nil {

Index: container/lxc/lxc_test.go
=== modified file 'container/lxc/lxc_test.go'
--- container/lxc/lxc_test.go 2013-07-17 22:41:36 +0000
+++ container/lxc/lxc_test.go 2013-07-17 23:38:15 +0000
@@ -12,6 +12,7 @@

   gc "launchpad.net/gocheck"
   "launchpad.net/goyaml"
+ "launchpad.net/loggo"

   "launchpad.net/juju-core/container/lxc"
   "launchpad.net/juju-core/instance"
@@ -46,6 +47,7 @@
  func (s *LxcSuite) SetUpTest(c *gc.C) {
   s.LoggingSuite.SetUpTest(c)
   s.TestSuite.SetUpTest(c)
+ loggo.GetLogger("juju.container.lxc").SetLogLevel(loggo.TRACE)
  }

  func (s *LxcSuite) TearDownTest(c *gc.C) {
@@ -96,6 +98,16 @@

   // Check the mount point has been created i...

[Ian Booth (wallyworld)]

LGTM

https://codereview.appspot.com/11491043/diff/1/container/lxc/lxc.go
File container/lxc/lxc.go (right):

https://codereview.appspot.com/11491043/diff/1/container/lxc/lxc.go#newcode131
container/lxc/lxc.go:131: linkLocation := filepath.Join(lxcRestartDir,
name+".conf")
perhaps make name+".conf" a function as it's used twice

https://codereview.appspot.com/11491043/

=== modified file 'container/lxc/lxc.go'
--- container/lxc/lxc.go	2013-07-15 01:16:52 +0000
+++ container/lxc/lxc.go	2013-07-18 02:57:28 +0000
@@ -28,6 +28,7 @@
 	containerDir        = "/var/lib/juju/containers"
 	removedContainerDir = "/var/lib/juju/removed-containers"
 	lxcContainerDir     = "/var/lib/lxc"
+	lxcRestartDir       = "/etc/lxc/auto"
 	lxcObjectFactory    = golxc.Factory()
 )
 
@@ -125,6 +126,12 @@
 		return 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, err
+	}
+	logger.Tracef("auto-restart link created")
 
 	// Start the lxc container with the appropriate settings for grabbing the
 	// console output and a log file.
@@ -154,6 +161,12 @@
 		logger.Errorf("failed to destroy lxc container: %v", err)
 		return err
 	}
+	// Remove the autostart symlink
+	if err := os.Remove(restartSymlink(name)); err != nil {
+		return err
+	}
+	logger.Tracef("auto-restart link removed")
+
 	// Move the directory.
 	logger.Tracef("create old container dir: %s", removedContainerDir)
 	if err := os.MkdirAll(removedContainerDir, 0755); err != nil {
@@ -206,6 +219,10 @@
 	return fmt.Sprintf(internalLogDirTemplate, lxcContainerDir, containerName)
 }
 
+func restartSymlink(name string) string {
+	return filepath.Join(lxcRestartDir, name+".conf")
+}
+
 const localConfig = `
 lxc.network.type = veth
 lxc.network.link = lxcbr0

=== modified file 'container/lxc/lxc_test.go'
--- container/lxc/lxc_test.go	2013-07-17 22:41:36 +0000
+++ container/lxc/lxc_test.go	2013-07-18 02:57:28 +0000
@@ -12,6 +12,7 @@
 
 	gc "launchpad.net/gocheck"
 	"launchpad.net/goyaml"
+	"launchpad.net/loggo"
 
 	"launchpad.net/juju-core/container/lxc"
 	"launchpad.net/juju-core/instance"
@@ -46,6 +47,7 @@
 func (s *LxcSuite) SetUpTest(c *gc.C) {
 	s.LoggingSuite.SetUpTest(c)
 	s.TestSuite.SetUpTest(c)
+	loggo.GetLogger("juju.container.lxc").SetLogLevel(loggo.TRACE)
 }
 
 func (s *LxcSuite) TearDownTest(c *gc.C) {
@@ -96,6 +98,16 @@
 
 	// Check the mount point has been created inside the container.
 	c.Assert(filepath.Join(s.LxcDir, name, "rootfs/var/log/juju"), jc.IsDirectory)
+	// Check that the config file is linked in the restart dir.
+	expectedLinkLocation := filepath.Join(s.RestartDir, name+".conf")
+	expectedTarget := filepath.Join(s.LxcDir, name, "config")
+	linkInfo, err := os.Lstat(expectedLinkLocation)
+	c.Assert(err, gc.IsNil)
+	c.Assert(linkInfo.Mode()&os.ModeSymlink, gc.Equals, os.ModeSymlink)
+
+	location, err := os.Readlink(expectedLinkLocation)
+	c.Assert(err, gc.IsNil)
+	c.Assert(location, gc.Equals, expectedTarget)
 }
 
 func (s *LxcSuite) TestStopContainer(c *gc.C) {
@@ -110,6 +122,8 @@
 	c.Assert(filepath.Join(s.ContainerDir, name), jc.DoesNotExist)
 	// but instead, in the removed container dir
 	c.Assert(filepath.Join(s.RemovedDir, name), jc.IsDirectory)
+	// Check that the restart link has been removed.
+	c.Assert(filepath.Join(s.RestartDir, name+".conf"), jc.DoesNotExist)
 }
 
 func (s *LxcSuite) TestStopContainerNameClash(c *gc.C) {

=== modified file 'container/lxc/test.go'
--- container/lxc/test.go	2013-07-17 22:42:53 +0000
+++ container/lxc/test.go	2013-07-18 02:57:28 +0000
@@ -28,6 +28,14 @@
 	return
 }
 
+// SetLxcRestartDir allows tests in other packages to override the
+// lxcRestartDir, which contains the symlinks to the config files so
+// containers can be auto-restarted on reboot.
+func SetLxcRestartDir(dir string) (old string) {
+	old, lxcRestartDir = lxcRestartDir, dir
+	return
+}
+
 // SetRemovedContainerDir allows tests in other packages to override the
 // removedContainerDir.
 func SetRemovedContainerDir(dir string) (old string) {
@@ -50,9 +58,11 @@
 	ContainerDir       string
 	RemovedDir         string
 	LxcDir             string
+	RestartDir         string
 	oldContainerDir    string
 	oldRemovedDir      string
 	oldLxcContainerDir string
+	oldRestartDir      string
 }
 
 func (s *TestSuite) SetUpSuite(c *gc.C) {}
@@ -66,6 +76,8 @@
 	s.oldRemovedDir = SetRemovedContainerDir(s.RemovedDir)
 	s.LxcDir = c.MkDir()
 	s.oldLxcContainerDir = SetLxcContainerDir(s.LxcDir)
+	s.RestartDir = c.MkDir()
+	s.oldRestartDir = SetLxcRestartDir(s.RestartDir)
 	s.Factory = mock.MockFactory()
 	s.oldFactory = SetLxcFactory(s.Factory)
 }