Re: [PATCH 4/9] automation: Add Arm containers to containerize script

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Fri, 23 Sep 2022, Michal Orzel wrote:
> Hi Anthony,
> 
> On 23/09/2022 15:56, Anthony PERARD wrote:
> > 
> > 
> > On Thu, Sep 22, 2022 at 03:40:53PM +0200, Michal Orzel wrote:
> >> Script automation/scripts/containerize makes it easy to build Xen within
> >> predefined containers from gitlab container registry. However, it is
> >> currently not possible to use it with Arm containers because they are not
> >> listed in the script. Populate the necessary entries.
> > 
> > FYI, those entry are just helper/shortcut/aliases, you can use any
> > arbitrary container with the script, it just more annoying.
> > 
> > Your patch here allows to write:
> >     CONTAINER=unstable-arm64v8 automation/scripts/containerize
> > but you could write the following instead, for the same result:
> >     CONTAINER=registry.gitlab.com/xen-project/xen/debian:unstable-arm64v8 
> > automation/scripts/containerize
> > 
> > I wonder if the script could select the right container base on the
> > architecture of the host, because "alpine" and "alpine-arm64v8" will not
> > both work on the same machine. It might be nice to just choose "alpine"
> > and the script would select the x86 or arm container automagically. Just
> > an idea, no need to do anything about it.
> I'm not in favor of adding the automatic selection based on the host.
> The reason is that on x86 you can run both x86 and e.g. Arm containers.
> You just need to use register qemu-user-static [1] to perform emulation.
> This is something widely used and I use that to test Arm images/containers on 
> x86 host.
> So you can run both alpine and alpine-arm64v8 on the same machine.

Yeah and modern Docker sets up qemu-user-static automatically without
the user having to do anything. Anthony, you can try it yourself: you
should be able to just:

  docker run -it registry.gitlab.com/xen-project/xen/debian:unstable-arm64v8

on your x86 host if you have a docker new enough