.github/workflows/docker.yml

name: Build Docker Image

on:
  push:
    branches:
      - main
    tags:
      - 'v*'
  pull_request:
    branches:
      - main

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

jobs:
  build-and-push:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
      id-token: write
    
    strategy:
      fail-fast: false
      matrix:
        include:
          # AMD64 platform
          - platform: linux/amd64
            suffix: amd64
          # ARM64 platform
          - platform: linux/arm64
            suffix: arm64

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

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

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

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            # Branch push
            type=ref,event=branch,suffix=-${{ matrix.suffix }}
            # Semver: full version
            type=semver,pattern={{version}},suffix=-${{ matrix.suffix }}
            # latest tag
            type=raw,value=latest-${{ matrix.suffix }},enable={{is_default_branch}}

      - name: Build and push Docker image
        uses: docker/build-push-action@v5
        with:
          context: .
          platforms: ${{ matrix.platform }}
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha,scope=${{ matrix.suffix }}
          cache-to: type=gha,mode=max,scope=${{ matrix.suffix }}
          pull: true
  
  # Merge multi-arch images into a unified tag
  merge-manifests:
    runs-on: ubuntu-latest
    needs: build-and-push
    if: github.event_name != 'pull_request'
    permissions:
      contents: read
      packages: write
    
    steps:
      - name: Log in to Container Registry
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      
      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=ref,event=branch
            type=semver,pattern={{version}}
            type=raw,value=latest,enable={{is_default_branch}}
      
      - name: Create and push manifest
        run: |
          TAGS="${{ steps.meta.outputs.tags }}"
          for tag in $TAGS; do
            echo "Merging tag: $tag"
            docker buildx imagetools create -t $tag \
              ${tag}-amd64 \
              ${tag}-arm64
          done