Since the app in this repository is Java-based, I think adding a kata that makes use of matrix for various Java versions would be neat.

I can volunteer to provide a PR for a kata :)

Has some inspiration.
https://rieckpil.de/github-actions-for-java-automate-your-maven-workflows/

A "trick" while they fix this, is to use an ubuntu-latest container for the checkout, in the workflow, and then store the artifact. And have a step with a self-hosted runner, that downloads the artifact.

Since this artifact is super-temporary, it would be nice to also set the retention_days: 1 (is 0 a value?) on it.

This could be added to the exercise with self-hosted runners.

Self-hosted runners sometime fail with missing permissions, because the run.sh presumably runs as UID 1001 (not sure?). It might be nice to chmod the gitlab-runner folder, so it has access to read/write it. (And tell people to do this in the exercise.)

GitHub workflows are a bit weird. When adding shell: bash under, e.g., https://github.com/eficode-academy/github-actions-katas/blob/main/.github/workflows/docker-image.yaml#L41 the chmod +x is not needed.

      - name: Clone-down
        uses: actions/checkout@v2
      - run: ci/build-app.sh
        shell: bash

https://github.com/ps-actions-sandbox/ActionsFundamentals

Things to consider:

• Link to make/create a new file.
• more screenshots
• have more optional tasks

Consider using the GitHub provided container registry. It shortens down the kata and reduce the risk of any issues creating an account.

If you think it's a valuable contribution I can implement it.

https://github.com/eficode-academy/github-actions-katas/blob/main/labs/08-selfhosted-runner.md

I think a small exercise to see ./run.sh check and that the runner is Idle and Offline when the daemon runs and is stopped could be interesting. I haven't seen the slides for the GitHub actions presentation, so you might already be covering it.

docker-compose.yaml version tag has been obsoleted.
"docker-compose" command has changed to "docker compose", as it is now a part of docker and not a separate package.