Allow the usage of this image as a GitHub Action

[vincentbrison]

As the GitHub Action shown in the README.md, we could add the ability to use this image as a GitHub action, letting the consumer of the action defining what he wants to do instead of fastlane call in our example.

Using GitHub Action args, we could enable/disable caching, and specifying docker image tag.

[vincentbrison]

What do you think about that @sjcqs ?

[sjcqs]

Great idea 👍

I can take a look

[sjcqs]

What need to be done:

1. Define how we want the user to interact with the Github Action (shell input ? shell file input ? fastlane lane support ? )
2. Add an action.yml which define the interface with the Github Action
3. Add an entrypoint to the dockerfile which will execute the user action

References:

• https://help.github.com/en/actions/building-actions/creating-a-docker-container-action
• https://help.github.com/en/actions/building-actions/creating-a-docker-container-action

[vincentbrison]

Imho, we should focus for now to add shell input support, as action consumer can just throw some fastlane or gradle command to test what can be done with the action. Furthermore, as actions are already yml code versioned with the project, the need of shell input file might just be an option.

About fastlane support, we dont need to do anything special as we would keep the following bloc in the action. So if the action consumer has a proper fastlane setup with proper Gemfile, Gemfile.lock and .ruby-version it would work out of the box.

    - name: Bundle install
      run: |
        bundle config path vendor/bundle
        bundle check || bundle install

[vincentbrison]

Well well, we can not use action inside an action. So no caching out of the box for now. Maybe we should at least include a default fastlane install (as we provide a default bundler install)?

[vincentbrison]

And to be able to run arbitrary docker-android image, we might need to use https://hub.docker.com/_/docker as host action image.

[vincentbrison]

I added branch https://github.com/faberNovel/docker-android/tree/feature/action to show an example on how to run docker in docker as mentioned in #45 (comment)

[vincentbrison]

Almost done, just need to pass command line args from action args to the docker image.