Proposal: docker build read Dockerfile from stdin · Issue ...
github.com › moby › mobyOct 14, 2016 · the stdin tar stream for a Dockerfile named -. The only collision with user data that I'm aware of is if the user wants to both provide a Dockerfile on stdin and access the original Dockerfile Dockerfile in the container build. This use case seems far-fetched and is easy to work-around/satisfy with renaming, symlinks, or hard links.