Sharing some madness: Just as a substitute for dockerfiles

[drewcassidy]

I really hate the Dockerfile syntax, and wished I could just use reusable blocks to set up various tools (I'm putting together CI runner images). I had the mad idea to use Just to do that

With the magic of the [script] attribute I've done just that

Any recipe marked in [script] gets run inside the container being built. Then some other recipes can set up the starting container or set environment variables. The outermost build recipe either calls just with the correct recipe name for the image requested, or sets up a container to do the same when run on Mac/windows.