Advice on using zmk extensions? Docker vs. host

[enoryw]

Disclaimer: new to Docker and west toolchain.

I'm using the Makefile with success. In the Docker container, my west.yml pulls the projects Urob's fork of ZMK and zmk-helpers it needs:

manifest:
  remotes:
    - name: urob
      url-base: https://github.com/urob
  projects:
    - name: zmk
      remote: urob
      revision: main
      import: app/west.yml
    - name: zmk-helpers
      remote: urob
      revision: v2
  self:
    path: config

Now I'm interested in using keymap-drawer to draw the keymap layout but it needs to reference/access zmk-helpers/include which is in the container. What's a recommended approach to incorporate keymap-drawers into the project?

Install pipx (needed to install keymap-drawer) and keymap-drawer in the container? Install it on the host system and use a Docker volume mount on the directory containing keymap-drawer to make it accessible in the container? Run keymap-drawer on the host system manually after the firmware gets built (this would require a local copy of zmk-helpers so probably not ideal)? Curious how one decides what is appropriate.

Since keymap-drawer is only used this zmk project, would it make sense to somehow keep it in the zmk-config repo (e.g. merely just copy the binary to the repo which I assume is frowned upon) so that if I ever share the repo it has all the tools necessarily to build the firmware and generate its image?

Any ideas much appreciated.

P.S. Docker-related questions:

• What's the usecase for make clean_image in the Makefile above? If I understand correctly, with make, the image is cached until there is an update to the image. When I run it, it does delete the image confirmed by docker image ls -a, but there is an error, is this expected?

/usr/bin/docker image rm zmk docker.io/zmkfirmware/zmk-build-arm:stable
Untagged: zmk:latest
Deleted: sha256:f33459de36badc368ba97dcc8aeac4e51a64684511c387235ec17571e8075179
Error response from daemon: No such image: zmkfirmware/zmk-build-arm:stable
make: *** [Makefile:42: clean_image] Error 1

• What's the point of building the firmware in an "ephemeral container" as in docker --rm in the Makefile? Why not re-use the same container?