Please clean up log files on lxc delete

[Martin Pitt]

It seems "lxc delete" does not remove log files in /var/log/lxd, so there's nothing that cleans them up and they pile up over time. I have no lxd containers defined on my laptop at the moment, but

$ ls /var/log/lxd/|wc -l
286

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: lxd 2.0.0-0ubuntu4
ProcVersionSignature: Ubuntu 4.4.0-22.38-generic 4.4.8
Uname: Linux 4.4.0-22-generic x86_64
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
CurrentDesktop: i3
Date: Thu Apr 28 09:20:17 2016
EcryptfsInUse: Yes
SourcePackage: lxd
UpgradeStatus: No upgrade log present (probably fresh install)

[Tycho Andersen (tycho-s)]

On Thu, Apr 28, 2016 at 07:24:23AM -0000, Martin Pitt wrote:
> Public bug reported:
>
> It seems "lxc delete" does not remove log files in /var/log/lxd, so
> there's nothing that cleans them up and they pile up over time. I have
> no lxd containers defined on my laptop at the moment, but

In some cases it is useful to keep these around for debugging. I
wouldn't mind something that deleted day old logs for containers that
don't exist, though.

> $ ls /var/log/lxd/|wc -l
> 286
>
> ProblemType: Bug
> DistroRelease: Ubuntu 16.04
> Package: lxd 2.0.0-0ubuntu4
> ProcVersionSignature: Ubuntu 4.4.0-22.38-generic 4.4.8
> Uname: Linux 4.4.0-22-generic x86_64
> ApportVersion: 2.20.1-0ubuntu2
> Architecture: amd64
> CurrentDesktop: i3
> Date: Thu Apr 28 09:20:17 2016
> EcryptfsInUse: Yes
> SourcePackage: lxd
> UpgradeStatus: No upgrade log present (probably fresh install)
>
> ** Affects: lxd (Ubuntu)
> Importance: Undecided
> Status: New
>
>
> ** Tags: amd64 apport-bug xenial
>
> --
> You received this bug notification because you are a member of Ubuntu
> containers team, which is subscribed to lxd in Ubuntu.
> Matching subscriptions: lxd
> https://bugs.launchpad.net/bugs/1576063
>
> Title:
> Please clean up log files on lxc delete
>
> Status in lxd package in Ubuntu:
> New
>
> Bug description:
> It seems "lxc delete" does not remove log files in /var/log/lxd, so
> there's nothing that cleans them up and they pile up over time. I have
> no lxd containers defined on my laptop at the moment, but
>
> $ ls /var/log/lxd/|wc -l
> 286
>
> ProblemType: Bug
> DistroRelease: Ubuntu 16.04
> Package: lxd 2.0.0-0ubuntu4
> ProcVersionSignature: Ubuntu 4.4.0-22.38-generic 4.4.8
> Uname: Linux 4.4.0-22-generic x86_64
> ApportVersion: 2.20.1-0ubuntu2
> Architecture: amd64
> CurrentDesktop: i3
> Date: Thu Apr 28 09:20:17 2016
> EcryptfsInUse: Yes
> SourcePackage: lxd
> UpgradeStatus: No upgrade log present (probably fresh install)
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/ubuntu/+source/lxd/+bug/1576063/+subscriptions

[Martin Pitt (pitti)]

So maybe lxd could clean up logs for nonexisting containers that are older than a few days at startup then?

[Martin Pitt (pitti)]

Alternatively lxd could also just log to syslog (i. e. the journal), then you'd have builtin rotation (using the container name as syslog identifier, so that it's easy to filter for it).

[Stéphane Graber (stgraber)]

Yeah, I think we should:
 - Wipe the log dir of containers that are more than a day old at startup and once a day (for when the daemon is long running)
 - Rotate lxc.log at every container start (startCommon)
 - Expire all log files (so everything but lxc.conf) after 2 days (same at startup + background job)

That should keep our log file situation under control.

[Stéphane Graber (stgraber)]

LXD itself doesn't log in /var/log/lxd, it's all the stuff we call which does, so patching everything to log to syslog isn't really an option.

[Stéphane Graber (stgraber)]

Tracked upstream here: https://github.com/lxc/lxd/issues/1966