[FFe] LXCFS 4.0 LTS

[Stéphane Graber]

LXCFS 4.0 LTS was released last week.

The highlights of this is:
 - cgroup2: Support for the new unified cgroup hierarchy
 - /proc/cpuinfo and cpu output in /proc/stat based on cpu shares
 - /proc/loadavg virtualization
 - pidfd supported process tracking

All of those except for the cgroup2 support are only enabled through opt-in by the user with an associated flag. So behavior wise, LXCFS 4.0 will be feature equivalent to what's there now.

LXCFS 4.0 is an LTS release with 5 years support from upstream, that along with future-proofing through the cgroup2 support is the main reason why we'd like this to be in 20.04 LTS.

LXCFS is in universe as its main user (LXD) uses an upstream build in a snap instead (already on 4.0). We nevertheless like to make sure that Ubuntu LTS releases include the deb form of the LXC and LXCFS LTS releases.

Related: https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1867535

Should this be granted, we'll most likely release an upstream bugfix release (4.0.1) and upload that to the archive, fixing a few initial issues we noticed over the week or so we've had running 4.0 in production on hundred of thousands of systems through the snap.

[Stéphane Graber (stgraber)]

4.0.1 has been released on Thursday with a number of fixes we came up with following the 4.0.0 rollout to our snap users. This is the release we'd be pushing into focal.

[Stéphane Graber (stgraber)]

https://discuss.linuxcontainers.org/t/lxcfs-4-0-1-lts-has-been-released/7130

[Iain Lane (laney)]

Sounds ok to me, go for it.

[Launchpad Janitor (janitor)]

This bug was fixed in the package lxcfs - 4.0.1-0ubuntu2

---------------
lxcfs (4.0.1-0ubuntu2) focal; urgency=medium

  * Cherry-pick upstream bugfix:
    - 0006-tests-Handle-different-lib-paths.patch

 -- Stéphane Graber <email address hidden> Wed, 25 Mar 2020 11:04:37 -0400