Add builtin directory on run if non-existent

[TomSweeneyRedHat]

Signed-off-by: TomSweeneyRedHat [email protected]

I think this will most likely replace #1125, but don't want to close that quite yet.

If an image has a builtin volume attached to it like:

            "Volumes": {
                "/var/lib/registry": {}
            },

Create the directory if it doesn't exist and fails the first stat, then attempt to continue processing.

I've one slight concern with this change. To replicate it prior to this change:

registry=$(buildah from registry:2)
buildah --debug run $registry -- htpasswd -Bbn testuser testpassword > /root/auth/htpasswd   # failed
buildah --debug run $registry -- htpasswd -Bbn testuser testpassword > /root/auth/htpasswd   # completed

After this change both runs work. However my concern is what's created on the host. After the first buildah run I see:

# find /var/lib/containers/storage -name registry
/var/lib/containers/storage/overlay/1fe8be720d6e3a8540dc649be8542b5304c46a88d5dcfac49729b3e8c267b4ac/diff/bin/registry
/var/lib/containers/storage/overlay/a4c34f0c87b2563d2835c48bffe2b940fea9719850c003c314e487e6af44da53/diff/etc/docker/registry
/var/lib/containers/storage/overlay/241c7d778023cd436c1148c16af2c039c8ae9f27d79bf66ee8dc6386848c6dea/diff/var/lib/registry

But I was thinking I should see something under

/var/lib/containers/storage/overlay/241c7d778023cd436c1148c16af2c039c8ae9f27d79bf66ee8dc6386848c6dea/merged

too, but I'm not. Am I overexpecting @nalind ?

Otherwise with this change I'm seeing the /var/lib/registry directory in the container as I'd expect.

[TomSweeneyRedHat]

Addresses #1121 and I didn't see @nalind's #1126 until I posted this, may retract this one.

[rh-atomic-bot]

☔ The latest upstream changes (presumably 87cb532) made this pull request unmergeable. Please resolve the merge conflicts.