We have a separate build cluster due to concerns about security and stability -- neither mounting the docker socket into a container nor docker-in-docker are comfortable solutions for our cluster managers. Having the ability to run container builds safely will be a huge benefit for my company.<p>We've looked into something like Bazel for its container builder, but that's a significant change that has to be made in every single project, most of which have perfectly fine build systems now.<p>And with all the FaaS systems which are continually building containers to host functions, this will be a godsend.