image-build-and-publish.yml

name: image-build-and-publish

# This workflow uses actions that are not certified by GitHub.
# They are provided by a third-party and are governed by 
# separate terms of service, privacy policy, and support
# documentation.

on:
  push:
    branches: [ "master" ]
    # Publish  tags as releases.
    tags: [ '*' ]
  release:
    types: [published]
  pull_request:
    branches: [ "master" ]

env:
  # Use docker.io for Docker Hub if empty
  REGISTRY: ghcr.io
  # github.repository as <account>/<repo>
  IMAGE_NAME: ${{ github.repository }}


jobs:
  build:

    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
      # This is used to complete the identity challenge
      # with sigstore/fulcio when running outside of PRs.
      id-token: write

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

      # Install the cosign tool except on PR
      # https://github.com/sigstore/cosign-installer
      #- name: Install cosign
      #  if: github.event_name != 'pull_request'
      #  uses: sigstore/cosign-installer@f3c664df7af409cb4873aa5068053ba9d61a57b6 #v2.6.0
      #  with:
      #    cosign-release: 'v1.13.1'


      # Workaround: https://github.com/docker/build-push-action/issues/461
      - name: Setup Docker buildx
        uses: docker/setup-buildx-action@v3

      # Login against a Docker registry except on PR
      # https://github.com/docker/login-action
      - name: Log into registry ${{ env.REGISTRY }}
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Extract metadata (tags, labels) for Docker
      # https://github.com/docker/metadata-action
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      - name: Create tags (version and latest) if this is a release
        if: github.event_name == 'release'
        id: tag-master
        run: |
          VERSION=$(cat VERSION)
          echo "VERSION=$VERSION" >> $GITHUB_ENV
          TAGS=$(echo "ghcr.io/$GITHUB_REPOSITORY:$VERSION" , "ghcr.io/$GITHUB_REPOSITORY:latest")
          echo "TAGS=$TAGS" >> $GITHUB_ENV
          
      - name: Create tags (version only) if this is NOT a release
        if: github.event_name != 'release'
        id: tag-non-master
        run: |
          VERSION="dev"
          echo "VERSION=$VERSION" >> $GITHUB_ENV
          TAGS=$(echo "ghcr.io/$GITHUB_REPOSITORY:$VERSION")
          echo "TAGS=$TAGS" >> $GITHUB_ENV
          
      - name: Show versions and tags
        run: |
          echo "Version: ${{ env.VERSION }}"
          echo "Tags: ${{ env.TAGS }}"
          
      # Build and push Docker image with Buildx (don't push on PR)
      # https://github.com/docker/build-push-action
      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@v5
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ env.TAGS }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      # Sign the resulting Docker image digest except on PRs.
      # This will only write to the public Rekor transparency log when the Docker
      # repository is public to avoid leaking data.  If you would like to publish
      # transparency data even for private images, pass --force to cosign below.
      # https://github.com/sigstore/cosign
      #- name: Sign the published Docker image
      #  if: ${{ github.event_name != 'pull_request' }}
      #  env:
      #    COSIGN_EXPERIMENTAL: "true"
      #  # This step uses the identity token to provision an ephemeral certificate
      #  # against the sigstore community Fulcio instance.
      #  run: echo "${{ steps.meta.outputs.tags }}" | xargs -I {} cosign sign {}@${{ steps.build-and-push.outputs.digest }}