RE: ISAR schroot mountpoints when running in container

["Moessbauer, Felix" <felix.moessbauer@siemens.com>]

> -----Original Message-----
> From: Bezdeka, Florian (T CED SES-DE) <florian.bezdeka@siemens.com>
> Sent: Friday, July 1, 2022 11:28 AM
> To: isar-users@googlegroups.com; kas-devel@googlegroups.com; Moessbauer,
> Felix (T CED SES-DE) <felix.moessbauer@siemens.com>
> Cc: Bossert, Andre (DI FA CTR SVC PRC2) <andre.bossert@siemens.com>; Kiszka,
> Jan (T CED) <jan.kiszka@siemens.com>; Schild, Henning (T CED SES-DE)
> <henning.schild@siemens.com>
> Subject: Re: ISAR schroot mountpoints when running in container
> 
> On Fri, 2022-07-01 at 09:11 +0000, Moessbauer, Felix wrote:
> > Hi,
> >
> > as we now have sbuild in ISAR next, first users stumble upon issues
> > when running the kas docker image in the gitlab-ci.
> > This requires additional mountpoints, as the schroot itself uses
> > overlayfs and stacking two overlayfs is not possible.
> > By that, you have to mount the overlay from the host.
> >
> > The kas-container script already has support for that, but it lacks
> > documentation on how to configure this manually.
> > In short: The following mountpoint has to be added (as RW):
> > /var/lib/schroot/union/overlay
> 
> So you added this mount point to your gitlab runner configuration? If so, can this
> mount (safely) be shared between multiple gitlab build jobs (running at the same
> time)?

The question boils down to "can this mountpoint safely be shared across ISAR runs", and this should be possible.
We run this code for a while and never experienced any sharing issues.

The schroots also have a PID component in their name. [1]
But I'm not 100% sure that the PIDs in the privileged container are unique across all containers.
At least for non-privileged containers you have local-only PIDs (or better, a local PID namespace).

Felix

[1] https://github.com/ilbers/isar/blob/next/meta/classes/sbuild.bbclass#L26

> 
> >
> > As this is neither an ISAR issue, nor a KAS issue per-se, I send this
> > to both lists.
> >
> > Felix
> > --
> > Siemens AG, Linux Expert Center
> > Otto-Hahn-Ring 6, 81739 München, Germany
> >