devcontainers/cli+kaniko

[pstoeckle]

I'm using dev containers regularly, and I want to build them using kaniko. However, since there kaniko/executor is no drop-in replacement for docker, one cannot simply run

devcontainer build \
  --docker-path /path/to/executor \
  ...

Since the corresponding issue in the devcontainers/cli has not been updated since quite some time: Did anyone manage to create a container image with nodeJS+devcontainers/cli+kaniko + some kind of magic wrapper so that one can use this to build devcontainers using kaniko?

[mzihlmann]

would it be using the root context for build? or just assemble existing layers together?

hmmm... it kind of has to anyways as the goal is to materialize the devenv to the running container. Just a very different UX to what you get elsewhere, but doesn't invalidate the idea and the appeal. It's basically what coder/coder does already for their format.

[pstoeckle]

AFAIK the devcontainer/cli

• downloads the devcontainer features/pulls them from the OCI registry
• generates a temporary Dockerfile which includes
  • the referenced base image or the content of the referenced `Dockerfile
  • for each devcontainer feature a RUN statement like RUN --mount=type=bind,from=dev_containers_feature_content_source,source=git-cliff_1,target=/tmp/build-features-src/git-cliff_1 cp -ar /tmp/build-features-src/git-cliff_1 /tmp/dev
• used docker or podman to build a container image based on this temporary Dockerfile

Before I start writing myself some kind of wrapper to make this work with kaniko as well, I wanted to ask whether someone in the community already did this.