Re: [RFC] container images for migration-test

[Fabiano Rosas <farosas@suse.de>]

Daniel P. Berrangé <berrange@redhat.com> writes:

> On Mon, Sep 14, 2026 at 08:58:09PM -0300, Fabiano Rosas wrote:
>> Hi, I just wanted to share and ask for feedback on some container images
>> I've been building as part of my testing of migration pull-requests.
>> 
>> From a Dockerfile from ./tests/docker/dockerfiles/ I'm producing the
>> following:
>> 
>> $ docker images
>> qemu-build-base:11.0.0                        b6efa198e93a        5.8GB
>> qemu-rootfs-base:11.0.0                       72bcb5418f4d       4.08GB
>> qemu:11.0.0                                   018a3f0f4dcc          2GB
>
> snip
>
>> 2) Neither the QEMU build nor the distro repos are reliable enough to
>> allow me to just "go back in time" and rebuild at any moment, I need to
>> keep the artifacts cached to avoid rebuilding. Otherwise it comes time
>> to send a PR and I discover that some python piece has changed or the
>> distro messed up the older repository.
>
> Yes, in general building old QEMU on new distros periodically
> hits trouble.  If building old QEMU, better reliability is
> achieved by using a distro release that was from the same
> timeframe as QEMU.  Is using containers targetting such old
> distro versions not an option ? The tests/docker/dockerfiles
> from the old QEMU branch ought to work ?
>

Yes, I'm doing just that. Some tweaks are needed still. For instance, my
script has something like this:

  dockerfile="tests/docker/dockerfiles/opensuse-leap.docker"

  sed -i 's/ncurses-devel//' $dockerfile

  if [ "$tag" = "10.1.0" ]; then
      sed -i 's/libLLVM19//' $dockerfile
  fi

> Our stable release branches have the same needs, and their
> CI is using the container images from the old branches.
>
> How far back in time do you need/want to go for migration
> testing ?  Is it sufficient to merely target versions for
> which mjt is still doing active maint work, so we can
> expect the containers to still work.
>

I'm currently testing against the previous 3 releases. I think 2
releases is probably enough.

> With regards,
> Daniel