The existing Bamboo support for building Docker images suggests (requires?) a build task to check out the repo where the Dockerfile lives as a separate build step. The Docker Build step appears to be limited in its configurability (any time a GUI wraps a command line, this is a risk).
The docker build documentation offers a very powerful option for building images from git, using a command like this:
docker build https://github.com/docker/rootfs.git#container:docker
In this example, #container specfies the branch and :docker specifies the working directory.
This is very desirable to me, as I have several containers in my build repo, and I will have different build jobs for each one (side note: it would be awesome to be able to trigger on a specific file changing, instead of any commit to the repo).
Unfortunately, I don't think this is possible. Am I wrong?
Update: while digging deeper, I ran across https://github.com/moby/moby/issues/36965 which indicates that older versions of git might not work. So this may definitely be a pipe dream for Bamboo for the near future.