[kolla] parent tags

I’m trying to be able to build a projects container without having to rebuild the parents which have different tags. The workflow I’m trying to achieve is: Build base and openstack-base with a tag of wallaby Build a container image for barbican with a tag of the version of barbican that is returned when doing `git describe` Build a container image for nova with a tag of the version of barbican that is returned when doing `git describe` etc.etc. I don’t seem to be able to do this without having to also build a new base and openstack-base with the same tag which is slow and also means a lot of disk space. Just wondering how other people do this sort of stuff? Any ideas? Thanks, Sam