docker-image.yml

# https://docs.github.com/en/actions/use-cases-and-examples/publishing-packages/publishing-docker-images
# https://docs.docker.com/build/ci/github-actions/manage-tags-labels/
name: Docker Image CI

on:
  push:
    branches:
      - "**"
    tags:
      - "v*.*.*"
env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build-and-push-image:
    runs-on: ubuntu-latest

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

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

      - name: Log in to the Container registry
        uses: docker/login-action@65b78e6e13532edd9afa3aa52ac7964289d1a9c1
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@9ec57ed1fcdbf14dcef7dfbe97b2010124a938b7
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          # generate Docker tags based on the following events/attributes
          tags: |
            type=schedule
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=semver,pattern={{major}}
            type=sha

      - name: Build and push Docker image
        id: push
        uses: docker/build-push-action@f2a1d5e99d037542a71f64918e516c093c6f3fc4
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}

      - name: Retag and push Docker image with additional tags
        run: |
          docker pull ${{ steps.meta.outputs.tags }}
          docker tag ${{ steps.meta.outputs.tags }} ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
          docker push ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest

      - name: Generate artifact attestation
        uses: actions/attest-build-provenance@v1
        with:
          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME}}
          subject-digest: ${{ steps.push.outputs.digest }}
          push-to-registry: true