Re: [PATCH v2 2/4] tests/docker: add support for podman remote access

["Daniel P. Berrangé" <berrange@redhat.com>]

On Thu, Jul 09, 2026 at 07:48:14AM -0700, Pierrick Bouvier wrote:
> On 2/10/2026 8:35 AM, Daniel P. Berrangé wrote:
> > When a developer's environment is already within a podman container it
> > is not possible to use 'podman' again to create containers. It will
> > usually result in wierd errors such as:
> > 
> >   Error: fatal error, invalid internal status, unable to create a new pause process: cannot re-exec process to join the existing user namespace. Try running "podman system migrate" and if that doesn't work reboot to recover
> > 
> > Podman offers the ability to talk to a daemon outside the container,
> > however, which could be leveraged by QEMU.
> > 
> > This can be used by invoking "podman --remote", or equivalently the
> > separate "podman-remote" binary:
> > 
> >   https://github.com/containers/podman/blob/main/docs/tutorials/remote_client.md
> > 
> > The current 'podman version' check is insufficient to detect the
> > inability to launch containers, so it is replaced with the stronger
> > 'podman info' check.
> > 
> > Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> > ---
> >  tests/docker/docker.py | 10 ++++++----
> >  1 file changed, 6 insertions(+), 4 deletions(-)
> > 
> > diff --git a/tests/docker/docker.py b/tests/docker/docker.py
> > index ff68c7bf6f..9e18b984f4 100755
> > --- a/tests/docker/docker.py
> > +++ b/tests/docker/docker.py
> > @@ -76,14 +76,16 @@ def _guess_engine_command():
> >      commands = []
> >  
> >      if USE_ENGINE in [EngineEnum.AUTO, EngineEnum.PODMAN]:
> > -        commands += [["podman"]]
> > +        commands += [["podman"], ["podman-remote"], ["podman", "--remote"]]
> >      if USE_ENGINE in [EngineEnum.AUTO, EngineEnum.DOCKER]:
> >          commands += [["docker"], ["sudo", "-n", "docker"]]
> >      for cmd in commands:
> >          try:
> > -            # docker version will return the client details in stdout
> > -            # but still report a status of 1 if it can't contact the daemon
> > -            if subprocess.call(cmd + ["version"],
> > +            # 'version' is not sufficient to prove a working binary
> > +            # for podman. 'info' is a stronger check that is more
> > +            # likely to correlate with ability to create containers,
> > +            # and required to detect the need for podman remote
> > +            if subprocess.call(cmd + ["info"],
> >                                 stdout=DEVNULL, stderr=DEVNULL) == 0:
> >                  return cmd
> >          except OSError:
> 
> Taking a look at why tcg tests are slow to compile, I reached this
> commit. It seems like that calling 'podman info' is 5 to 10 times slower
> than calling 'podman version'.
> Thus, a container run now takes +1s when it was 0.2 before.

Hmmm, but we call 'docker.py probe' in configure and cache the result,
so that probe should only be done once.  0.2 vs 1s is just noise in
the context of configure.

That you're seeing any negative effects suggests that we've got
something not using the cached probe result, which we should fix.

With regards,
Daniel
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