Trusty's libselinux1 causes issues with Precise's upstart during dist-upgrade

[Michael Schaller]

[Impact]

 * During upgrade to trusty, upstart would be forcefully re-executed, even if it doesn't support stateful re-execution. This means all job statuses is lost.

 * Upgrade strategy for upstart is that when stateful re-execution is not supported, a flag should be left to re-execute upstart on shut-down only.

 * The culprit is in libselinux1, a new dependency of upstart in trusty that does not have appropriate login in its postinst.

[Test Case]

 * Using precise's upstart as pid one execute:
$ initctl list

 * Install libselinux1 from trusty-proposed
 * Execute
$ initctl list

 * The two lists should be largely the same, with state of jobs preserved.
 * /var/run/init.upgraded file-flag should be present.

[Other Info]

 * Original bug report:

Hi everyone,

During troubleshooting of bug http://pad.lv/1303891 I've also discovered that Precise's upstart version doesn't work with Trusty's libselinux1. This is a major issue during a dist-upgrade from Precise to Trusty as upstart is severely affected by this and looses track of service PIDs which prevents service reloads.

Can someone add a Breaks for Precise's upstart version to Trusty's libselinux1 debian/control file?

Reproduction instructions:
Install Ubuntu 12.04.4.

$ sudo apt-get update -qq && sudo apt-get dist-upgrade -qqy
<no output; no updates>

$ initctl list
avahi-daemon start/running, process 765
...

$ sudo sed -i 's/precise/trusty/g' /etc/apt/sources.list

$ sudo apt-get update -qq
<no ouput; no errors>

$ sudo apt-get install libselinux1 -y
...

New dmesg lines:
[ 256.032898] init: Re-executing /sbin/init

New syslog lines:
Apr 23 14:51:40 test upstart-socket-bridge[1090]: Disconnected from Upstart
Apr 23 14:51:40 test upstart-udev-bridge[595]: Disconnected from Upstart

$ initctl list
avahi-daemon stop/waiting
...

Upstart lost track of service PIDs. Commands like 'initctl reload dbus' will fail.

[Dimitri John Ledkov (xnox)]

upstart in precise does not link/use libselinux, nor supports stateful re-execution.
If one re-execs precise's upstart, it looses state of all jobs.
upstart in trusty does support stateful re-execution and links against libselinux.
I'll inspect libselinux post-install scripts, but it should only re-execute upstart if and only if "initctl version" is > 1.10

[Dimitri John Ledkov (xnox)]

if [ "$1" = "configure" ]; then
       # Restart init. If it fails, there is nothing we can do, so
      # just ignore the error (NOTE: Borrowed from libc6.postinst)
      telinit u 2>/dev/null || true ; sleep 1
 9fi

ph, yes, libselinux postinst is not upgrades from precise friendly.

[Launchpad Janitor (janitor)]

This bug was fixed in the package libselinux - 2.2.2-1ubuntu1

---------------
libselinux (2.2.2-1ubuntu1) utopic; urgency=high

  * Correct libselinu1 postinst for re-executing upstart. (LP: #1313712)
  * Fix FTBFS against ruby2.1.
 -- Dimitri John Ledkov <email address hidden> Mon, 28 Apr 2014 14:51:48 +0100

[Chris J Arges (arges)]

Hello Michael, or anyone else affected,

Accepted libselinux into trusty-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/libselinux/2.2.2-1ubuntu0.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Michael Schaller (misch-9)]

$ apt-cache policy libselinux1
libselinux1:
  Installed: 2.1.0-4.1ubuntu1
  Candidate: 2.2.2-1ubuntu0.1
  Version table:
     2.2.2-1ubuntu0.1 0
        500 http://de.archive.ubuntu.com/ubuntu/ trusty-proposed/main amd64 Packages
     2.2.2-1 0
        500 http://de.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
 *** 2.1.0-4.1ubuntu1 0
        100 /var/lib/dpkg/status

> Took snapshot of VM

$ sudo apt-get install libselinux1=2.2.2-1
...

$ initctl list | grep process
<no output>

> Issue present in version 2.2.2-1
> Reverted to snapshot of VM

$ sudo apt-get install libselinux1=2.2.2-1ubuntu0.1
...

$ initctl list | grep process
avahi-daemon start/running, process 732
rsyslog start/running, process 685
tty4 start/running, process 1222
...

> Issue is fixed in version 2.2.2-1ubuntu0.1

[Launchpad Janitor (janitor)]

This bug was fixed in the package libselinux - 2.2.2-1ubuntu0.1

---------------
libselinux (2.2.2-1ubuntu0.1) trusty; urgency=high

  * Correct libselinu1 postinst for re-executing upstart. (LP: #1313712)
 -- Dimitri John Ledkov <email address hidden> Mon, 28 Apr 2014 14:51:48 +0100

[Chris Halse Rogers (raof)]

The verification of the Stable Release Update for libselinux has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regresssions.

[Michael Schaller (misch-9)]

Thank you Dimitri for fixing this issue.