docker-publish.yml

name: Build and publish Docker image

on:
  push:
    branches: [ "main" ]
    tags: [ 'v*.*.*' ]
  pull_request:
    branches: [ "main" ]

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        platform:
          - linux/amd64
          - linux/arm64
#          - linux/arm/v7

    permissions:
      contents: read
      packages: write
      id-token: write

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Setup Docker buildx
        uses: docker/setup-buildx-action@v3

      - name: Log into registry ${{ env.REGISTRY }}
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Prepare platform name
        id: prep
        run: echo "platform=$(echo ${{ matrix.platform }} | cut -d'/' -f2)" >> $GITHUB_OUTPUT

      - name: Print platform name
        run: |
          echo "names: ${{ steps.prep.outputs.platform }}"

      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
#          flavor: |
#            latest=${{ github.ref == 'refs/heads/main' }}
          tags: |
            value=${{ steps.prep.outputs.platform }}

      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          platforms: ${{ steps.prep.outputs.platform }}

      - name: Export digest
        run: |
          mkdir -p /tmp/digests
          digest="${{ steps.build-and-push.outputs.digest }}"
          touch "/tmp/digests/${digest#sha256:}"

      - name: Upload digest
        uses: actions/upload-artifact@v4
        with:
          name: digests-${{ steps.prep.outputs.platform }}
          path: /tmp/digests/*
          if-no-files-found: error
          retention-days: 1

  merge:
    runs-on: ubuntu-latest
    needs:
      - build

    permissions:
      contents: read
      packages: write
      id-token: write

    steps:
      - name: Download digests
        uses: actions/download-artifact@v4
        with:
          path: /tmp/digests
          pattern: digests-*
          merge-multiple: true

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      - name: Log into registry ${{ env.REGISTRY }}
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Print digest
        working-directory: /tmp/digests
        run: |
          registry=${{ env.REGISTRY }}
          image_name=${{ env.IMAGE_NAME }}
          echo $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
          $(for f in ./*; do printf "${registry,,}/${image_name,,}@sha256:%s " "${f#./}"; done)

      - name: Create manifest list and push
        working-directory: /tmp/digests
        run: |
          registry=${{ env.REGISTRY }}
          image_name=${{ env.IMAGE_NAME }}
          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
          $(for f in ./*; do printf "${registry,,}/${image_name,,}@sha256:%s " "${f#./}"; done)

      - name: Inspect image
        run: |
          registry=${{ env.REGISTRY }}
          image_name=${{ env.IMAGE_NAME }}
          docker buildx imagetools inspect ${registry,,}/${image_name,,}:${{ steps.meta.outputs.version }}