Thanks for following up. It wouldn't be a trivial change to add
buildah support in kolla, but it would have saved reimplementing the
task parallelisation in Tripleo and would benefit others too. Never
mind.
To be fair, at the time I wrote the code in python-tripleoclient the container tooling wasn't really stable and we weren't sure about the directions we would take yet; which is the main reason which drove us to not invest too much time into refactoring Kolla to support a tool that we weren't sure we would end up using in production for the container image building.
It has been a few months now and so far it works ok for our needs; so if there is interest in supporting Buildah in Kolla then we might want to do the refactor and of course TripleO would use this new feature.
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