name: container image

on:
  push:
  pull_request:
  schedule:
  - cron: '0 20 * * 5'

jobs:
  docker-build:
    runs-on: ubuntu-20.04
    steps:
    - uses: docker/setup-qemu-action@v2.2.0
    - uses: docker/setup-buildx-action@v2.6.0
    # > By default, this action uses the Git context so you don't need to use
    # > the actions/checkout action to checkout the repository because this
    # > will be done directly by buildkit. [...]
    # > any file mutation in the steps that precede [...] will be ignored
    # https://github.com/marketplace/actions/build-and-push-docker-images
    - uses: docker/build-push-action@v4.1.1
      with:
        platforms: |
          linux/amd64
          linux/arm/v7
        # potential alternative: https://github.com/docker/metadata-action
        build-args: REVISION=${{ github.sha }}
        # > $ skopeo copy --all oci-archive:oci-container-image.tar \
        # >     docker://quay.io/fphammerle/test:test
        # > [...]
        # > FATA[0056] Error creating an updated image manifest: Error preparing
        # . updated manifest, layer "sha256:[...]": unsupported MIME type for
        # . compression: application/vnd.in-toto+json
        provenance: false
        # https://docs.docker.com/engine/reference/commandline/buildx_build/#output
        # https://github.com/opencontainers/image-spec
        outputs: type=oci,dest=oci-container-image.tar
    - uses: actions/upload-artifact@v3.1.2
      with: {path: oci-container-image.tar}