Talia Wong

> So far I haven't been able to determine that they're using actual disk space usage versus just multiplying the # of images by their individual sizes You could inspect...

Interesting, I couldn't find any reference to that syntax in the [Dockerfile reference](https://github.com/moby/buildkit/blob/b6de3ca443b8a359bb4bc414280e43068494106c/frontend/dockerfile/docs/reference.md#ARG). But if it's broken anyway then maybe that and the documentation are separate issues?

So messing around this has some of the right behavior: ```dockerfile ARG EXAMPLE FROM busybox:latest ARG EXAMPLE ARG _=${EXAMPLE:?"Must provide EXAMPLE"} RUN true RUN echo ${EXAMPLE} ``` It correctly fails...

Well I discovered a hacky way to do this that doesn't invalidate build caches: ```dockerfile ARG EXAMPLE FROM scratch AS validate-example ARG EXAMPLE ARG _=${EXAMPLE:?"Must provide EXAMPLE"} FROM busybox:latest RUN...

Broadly I would expect the same behavior with and without `--parents` with respect to what is validated.

Having run into many annoyances with managed node groups I'm also very interested in this. I poked around the code a bit though and it looks like one major thing...

The extra round trips can add up. One example is where IAM roles are used to provide EKS access tokens, and then some scripting is done around `kubectl` that ends...