osbuilder: Evaluate whether makes sense to keep supporting the alpine rootfs

[fidencio]

This is part of a bigger effort to simplify what we support and ensure we actually test what we say we support.

The outcome of this should be:

• Whether we support or not the alpine rootfs
• Where do we use the alpine rootfs
• Who's the person responsible for maintaining the alpine rootfs

All the information will end up going to a Wiki page so we can actually act whenever an issue shows up or an update has to be made.

[fidencio]

alpine is current used as part of the VFIO CI, as it can be seen here:

	echo "Installing initrd image"
	sudo -E AGENT_INIT=yes TEST_INITRD=yes osbuilder_distro=alpine PATH=$PATH "${ci_dir_name}/install_kata_image.sh"

Do we need alpine for that? Could it be done with another distro? My understanding is that we rely on the alpine image as that's a really minimal one.

@devimc, opinions?

[skaegi]

FWIW my team is currently using the alpine based rootfs -- in theory because of its small size. ;)

[stevenhorsman]

This might be an interesting discussion to have - I think that now we are only testing the ubuntu and mariner based rootfs images now, unless I'm missing something?

In my mind not testing, means we don't support/maintain them, so maybe we should consider removing some of the other options (alpine, centos, clearlinux, debian) and they mostly haven't been updated for a while. It depends if we want to maintain them on behalf of downstream, but then we should expand our CI to actually test them?