# On every commit, build and push a Docker image to the GitHub Container
# registry and to DockerHub.
#
# The resulting Docker images are tagged with the full commit hash, the git
# branch name, the git tag, and the 'latest' tag for the latest commit to
# master.
#
# https://github.com/danbooru/danbooru/pkgs/container/danbooru
# https://hub.docker.com/r/evazion/danbooru
#
# https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry
# https://docs.github.com/en/packages/managing-github-packages-using-github-actions-workflows/publishing-and-installing-a-package-with-github-actions
# https://docs.github.com/en/actions/guides/publishing-docker-images

name: Docker Build

# https://docs.github.com/en/actions/reference/events-that-trigger-workflows
on: [push, create, workflow_dispatch]

# https://docs.github.com/en/actions/reference/authentication-in-a-workflow#permissions-for-the-github_token
# https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#jobsjob_idpermissions
permissions:
  packages: write

jobs:
  docker-build:
    runs-on: ubuntu-latest

    steps:
      # https://github.com/docker/setup-qemu-action
      # https://github.com/docker/setup-buildx-action#with-qemu
      #- name: Set up QEMU
      #  uses: docker/setup-qemu-action@v1
      #  with:
      #    platforms: arm64

      # https://github.com/docker/setup-buildx-action
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2

      # https://github.com/docker/login-action
      # https://github.com/docker/build-push-action/blob/master/docs/advanced/push-multi-registries.md
      - name: Login to Github Container Registry
        uses: docker/login-action@v2
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
          password: ${{ github.token }}

      - name: Login to DockerHub
        uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      # Generate Docker tags from Git tags.
      # https://github.com/docker/metadata-action
      - name: Generate Docker tags
        uses: docker/metadata-action@v4
        id: metadata
        with:
          images: |
            docker.io/evazion/danbooru
            ghcr.io/danbooru/danbooru
          tags: |
            type=sha,format=long,prefix=
            type=ref,event=branch
            type=ref,event=tag
            type=ref,event=pr
          # Tag `latest` on every commit pushed to master
          # https://github.com/docker/metadata-action/issues/112
          flavor: |
            latest=${{ github.ref == 'refs/heads/master' }}

      # https://github.com/docker/build-push-action
      - name: Build image
        uses: docker/build-push-action@v3
        with:
          push: true
          tags: ${{ steps.metadata.outputs.tags }}
          labels: ${{ steps.metadata.outputs.labels }}

          #platforms: linux/amd64,linux/arm64
          platforms: linux/amd64

          # https://github.com/docker/build-push-action/blob/master/docs/advanced/cache.md#registry-cache
          # https://dev.to/pst418/speed-up-multi-stage-docker-builds-in-ci-cd-with-buildkit-s-registry-cache-11gi
          cache-from: type=registry,ref=ghcr.io/${{ github.repository }}:buildcache
          cache-to: type=registry,ref=ghcr.io/${{ github.repository }}:buildcache,mode=max

          build-args: |
            SOURCE_COMMIT=${{ github.sha }}