docker-publish.yml

name: Docker

# thanks to https://github.com/sredevopsorg/multi-arch-docker-github-workflow

on:
  push:
    branches: ["main"]
    tags: ["v*.*.*"]
  pull_request:
    branches: ["main"]
  workflow_dispatch:
env:
  IMAGE_NAME: ${{ github.repository }}
  DOCKERHUB_USERNAME: c4illin

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  # The build job builds the Docker image for each platform specified in the matrix.
  build:
    strategy:
      fail-fast: false
      matrix:
        platform:
          - linux/amd64
          - linux/arm64

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

    runs-on: ${{ matrix.platform == 'linux/amd64' && 'ubuntu-24.04' || matrix.platform == 'linux/arm64' && 'ubuntu-24.04-arm' }}

    name: Build Docker image for ${{ matrix.platform }}

    steps:
      - name: Prepare environment for current platform
        # This step sets up the environment for the current platform being built.
        # It replaces the '/' character in the platform name with '-' and sets it as an environment variable.
        # This is useful for naming artifacts and other resources that cannot contain '/'.
        # The environment variable PLATFORMS_PAIR will be used later in the workflow.
        id: prepare
        run: |
          platform=${{ matrix.platform }}
          echo "PLATFORM_PAIR=${platform//\//-}" >> $GITHUB_ENV

      - name: Checkout repository
        uses: actions/checkout@v6

      - name: downcase REPO
        run: |
          echo "REPO=${GITHUB_REPOSITORY@L}" >> "${GITHUB_ENV}"

      - name: Docker meta default
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ghcr.io/${{ env.REPO }}

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3
        with:
          platforms: ${{ matrix.platform }}

      - name: Login to GitHub Container Registry
        # here we only login to ghcr.io since the this only pushes internal images
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build and push by digest
        id: build
        uses: docker/build-push-action@v6
        env:
          DOCKER_BUILDKIT: 1
        with:
          context: .
          platforms: ${{ matrix.platform }}
          labels: ${{ steps.meta.outputs.labels }}
          annotations: ${{ steps.meta.outputs.annotations }}
          outputs: type=image,name=ghcr.io/${{ env.REPO }},push-by-digest=true,name-canonical=true,oci-mediatypes=true
          push: ${{ github.event_name != 'pull_request' || (github.event.pull_request.head.repo.full_name == github.repository && contains(fromJSON('["COLLABORATOR","MEMBER","OWNER"]'), github.event.pull_request.author_association)) }}
          cache-from: type=gha,scope=${{ matrix.platform }}
          cache-to: type=gha,mode=max,scope=${{ matrix.platform }}

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

      - name: Upload digest
        uses: actions/upload-artifact@v6
        with:
          name: digests-${{ env.PLATFORM_PAIR }}
          path: /tmp/digests/*
          if-no-files-found: error
          retention-days: 1

  merge:
    if: ${{ github.event_name != 'pull_request' || (github.event.pull_request.head.repo.full_name == github.repository && contains(fromJSON('["COLLABORATOR","MEMBER","OWNER"]'), github.event.pull_request.author_association)) }}
    name: Merge Docker manifests
    runs-on: ubuntu-latest

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

    needs:
      - build
    steps:
      - name: Download digests
        uses: actions/download-artifact@v7
        with:
          path: /tmp/digests
          pattern: digests-*
          merge-multiple: true

      - name: downcase REPO
        run: |
          echo "REPO=${GITHUB_REPOSITORY@L}" >> "${GITHUB_ENV}"

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

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

      - name: Login to GitHub Container Registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ env.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Get execution timestamp with RFC3339 format
        id: timestamp
        run: |
          echo "timestamp=$(date -u +"%Y-%m-%dT%H:%M:%SZ")" >> $GITHUB_OUTPUT

      - name: Create manifest list and push
        working-directory: /tmp/digests
        run: |
          docker buildx imagetools create \
            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
            --annotation='index:org.opencontainers.image.description=${{ github.event.repository.description }}' \
            --annotation='index:org.opencontainers.image.created=${{ steps.timestamp.outputs.timestamp }}' \
            --annotation='index:org.opencontainers.image.url=${{ github.event.repository.url }}' \
            --annotation='index:org.opencontainers.image.source=${{ github.event.repository.url }}' \
            $(printf 'ghcr.io/${{ env.REPO }}@sha256:%s ' *)

      - name: Inspect image
        run: |
          docker buildx imagetools inspect 'ghcr.io/${{ env.REPO }}:${{ steps.meta.outputs.version }}'