You can call a dockerfile whatever you want. You'll need to specify the filename at build. But, the name really doesn't matter. You can call it umptysquat.txt a

You can call a dockerfile whatever you want. You'll need to specify the filename at build. But, the name really doesn't matter. You can call it umptysquat.txt and it'll build you a container. In the wild, I've seen (case insensitive) Dockerfile (obvs), Containerfile, and Container.