Current stargz snapshotter pkg doesn't contain registry configuration and the
client of that pkg needs to pass it to that pkg. So this commit includes changes
of propagating buildkitd's registry configuration to stargz snapshotter.
But this is a partial integration of registry logic between buildkitd and stargz
snapshotter because buildkitd's session-based authentication logic is still not
applied to stargz snapshotter. This means private images that require
`~/.docker/config.json` creds can't be lazily pulled yet.
Signed-off-by: ktock <ktokunaga.mail@gmail.com>
ktock
Sebastiaan van Stijn
Akihiro Suda