I interpret each directive in a Dockerfile as creating a new layer of an image. ...

		koito17 on May 14, 2024 \| parent \| context \| favorite \| on: Using ARG in a Dockerfile – beware the gotcha I interpret each directive in a Dockerfile as creating a new layer of an image. So this ARG-before-FROM gotcha doesn't feel like a gotcha to me, but rather, the consequence of literally interpreting "ARG" and not knowing the side-effects of a directive in a Dockerfile. (Yes, even WORKDIR, ENTRYPOINT, and related instructions create a layer, albeit a 0-byte one)

It persists across every other new layer. It just doesn't persist across FROM.