Merge lp:~kampka/ubuntu/quantal/lxc/upstart-instance into lp:ubuntu/quantal/lxc

[Christian Kampka]

This change proposes that upstart takes care of running and managing lxc container instances instead of having them run as daemons.
This has some advantages:
 - lxc containers can benefit from upstart supervision, eg. respawn can be easily enabled, and parallel job execution
   At the moment with serial execution, stopping the lxc service can (worst case)
   take up to n times $LXC_SHUTDOWN_TIMEOUT, n being the number of containers running.
   Having upstart manage instance shutdown avoids this problem.
 - Administrators can write upstart jobs that run on lxc container startup/shutdown of a specific container.
   Consider for example a job that enables transparent port 80 routing once a container names "squid" comes up.

I have not found any possibility to assign the instance kill timeout dynamically so for now it's fixed at two minutes.

[James Hunt (jamesodhunt)]

Just a couple of points:

- It would be extremely useful if you added a 'usage' stanza to allow admins to see how to run the lxc-instance job as currently, if you forget to specify it, the job does nothing, silently.

  For example, add something like:

  usage "NAME=name of LXC instance, CONFIG=full path to configuration file"

  See http://upstart.ubuntu.com/cookbook/#usage

- Shouldn't that 'stop on' condition be 'stop on stopping lxc' ('stopping' rather than 'stopped')?

[lp:~kampka/ubuntu/quantal/lxc/upstart-instance]

144. By Christian Kampka on 2012-09-17

* [Upstart]
  - add usage stanza to lxc-instance job
  - stop lxc-instance on 'stopping lxc'

[Christian Kampka (kampka)]

Thanks for the input, agreed on both points.

[Serge Hallyn (serge-hallyn)]

Thanks, Christian, I really like it.

I've changed the topic of the bug to add '[FFE]' - it's probably too late for quantal, but I'll see whether the release team is willing to approve this.

James Hunt,

With Christian having addressed your feedback, do you have any other comments?

review: Approve

[Stéphane Graber (stgraber)]

Marking as work in progress as it's been rejected for Quantal. Can you resubmit it for R once the archive opens next month?

Thanks for your work.

Unmerged revisions

144. By Christian Kampka on 2012-09-17

* [Upstart]
  - add usage stanza to lxc-instance job
  - stop lxc-instance on 'stopping lxc'

143. By Christian Kampka on 2012-09-12

Have upstart run lxc instances

=== modified file 'debian/changelog'
--- debian/changelog	2012-09-14 11:45:46 +0000
+++ debian/changelog	2012-09-17 10:17:18 +0000
@@ -11,6 +11,7 @@
 
   [ Serge Hallyn ]
   * 0214-give-pclose-errno: help debug pclose failures when lxc runs scripts.
+<<<<<<< TREE
   * 0215-lxc-clone-name-arg: fix incorrect checking for --name argument.
     (LP: #1049914)
   * 0216-hook-kmsg-to-console: link /dev/kmsg to /dev/console so init log
@@ -49,6 +50,11 @@
     (LP: #1050351)
 
  -- Serge Hallyn <[e-mail]>  Thu, 13 Sep 2012 12:02:45 -0500
+=======
+  * Have upstart run lxc instances 
+
+ -- Serge Hallyn <[e-mail]>  Thu, 06 Sep 2012 22:08:55 -0500
+>>>>>>> MERGE-SOURCE
 
 lxc (0.8.0~rc1-4ubuntu33) quantal; urgency=low
 
 
=== added file 'debian/lxc.lxc-instance.upstart'
--- debian/lxc.lxc-instance.upstart	1970-01-01 00:00:00 +0000
+++ debian/lxc.lxc-instance.upstart	2012-09-17 10:17:18 +0000
@@ -0,0 +1,23 @@
+description "lxc instance"
+author "Christian Kampka <[e-mail]>"
+
+stop on stopping lxc
+
+# wait for 120 seconds for container to shutdown before killing it
+kill timeout 120
+
+# send SIGPWR to container to trigger a shutdown (see lxc-shutdown(1))
+kill signal SIGPWR
+
+
+instance $NAME
+usage "NAME=name of LXC instance, CONFIG=full path to configuration file"
+
+pre-start script
+
+	lxc-info -n $NAME 2>/dev/null | grep state | grep -q "RUNNING" && {stop; exit 0; }
+	[ -f $CONFIG ] || {stop; exit 0; }
+
+end script
+
+exec lxc-start -n $NAME -f $CONFIG
 
=== modified file 'debian/lxc.upstart'
--- debian/lxc.upstart	2012-05-07 21:22:26 +0000
+++ debian/lxc.upstart	2012-09-17 10:17:18 +0000
@@ -5,7 +5,6 @@
 stop on starting rc RUNLEVEL=[016]
 
 env LXC_AUTO="false"
-env LXC_SHUTDOWN_TIMEOUT="120"
 
 pre-start script
 	[ -f /etc/default/lxc ] && . /etc/default/lxc
@@ -24,20 +23,6 @@
 	ls /etc/lxc/auto/* > /dev/null 2>&1 || exit 0;
 	for f in /etc/lxc/auto/*; do
 		c="$(basename $f .conf)"
-		lxc-info -n $c 2>/dev/null | grep state | grep -q "RUNNING" || lxc-start -n $c -f $f -d
-	done
-end script
-
-post-stop script
-	[ -f /etc/default/lxc ] && . /etc/default/lxc
-
-	[ "x$LXC_AUTO" = "xtrue" ] || { exit 0; }
-
-	ls /etc/lxc/auto/* > /dev/null 2>&1 || exit 0;
-	for f in /etc/lxc/auto/*; do
-		c="$(basename $f .conf)"
-		lxc-shutdown -n $c -w -t $LXC_SHUTDOWN_TIMEOUT &
-	done
-
-	wait
+		start lxc-instance NAME=$c CONFIG=$f
+	done
 end script
 
=== modified file 'debian/rules'
--- debian/rules	2012-09-13 15:46:54 +0000
+++ debian/rules	2012-09-17 10:17:18 +0000
@@ -92,6 +92,7 @@
 override_dh_installinit:
 	dh_installinit --no-restart-on-upgrade --name=lxc
 	dh_installinit --no-restart-on-upgrade --name=lxc-net
+	dh_installinit --no-restart-on-upgrade --name=lxc-instance
 
 override_dh_strip:
 	dh_strip --dbg-package=lxc-dbg