docker-image.yml

name: docker image CI

on:
  push:
    paths-ignore:
      - '**.md'
      - '.gitignore'
      - '.dockerignore'
  pull_request:
    paths-ignore:
      - '**.md'
      - '.gitignore'
      - '.dockerignore'

env:
  REGISTRY: ghcr.io
  DOCKER_HUB_OWNER: phlummox

jobs:

  build:

    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v4

    - name: Log in to Docker Hub
      if: github.event_name != 'pull_request'
      uses: docker/login-action@v3
      with:
        username: ${{ secrets.DOCKER_USERNAME }}
        password: ${{ secrets.DOCKER_PASSWORD }}

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

    # needed? not sure. used for caching.
    - name: Set up Docker Buildx
      uses: docker/setup-buildx-action@v3

    - name: Build Docker image
      shell: bash
      run: |
        set -x

        # build the image using paths appropriate for the ghcr.io registry
        echo "registry is ${{ env.REGISTRY }}"
        echo "repo is ${{ github.repository }}"
        echo "repo owner is ${{ github.repository_owner }}"

        image_bit=$(make print-image-name)
        NAMESPACE="${{ env.REGISTRY }}/${{ github.repository }}/${{ github.repository_owner }}/"
        BUILD_ARGS="--pull --cache-from=type=registry,ref=${NAMESPACE}${image_bit}:latest \
                    --cache-to=type=inline --load"

        # try pull?
        docker pull ${NAMESPACE}${image_bit}:latest || true

        make BUILD_ARGS="${BUILD_ARGS}" NAMESPACE="${NAMESPACE}" DOCKER="docker buildx" build

    - name: push to github registry
      if: github.event_name != 'pull_request'
      shell: bash
      run: |
        set -x
        set -euo pipefail

        image_bit=$(make print-image-name)
        image="${{ env.REGISTRY }}/${{ github.repository }}/${{ github.repository_owner }}/${image_bit}"
        version=$(make print-image-version)

        docker push ${image}:${version}
        docker tag  ${image}:${version} ${image}:latest
        docker push ${image}:latest

    - name: push to docker registry
      if: startsWith(github.ref, 'refs/tags/v')
      shell: bash
      run: |
        set -x
        set -euo pipefail

        image_bit=$(make print-image-name)
        version=$(make print-image-version)

        ghcr_image="${{ env.REGISTRY }}/${{ github.repository }}/${{ github.repository_owner }}/${image_bit}"

        # namespace already includes trailing "/"
        docker_hub_image=$(make print-image-namespace)${image_bit}

        docker tag ${ghcr_image}:${version} ${docker_hub_image}:${version}
        docker push ${docker_hub_image}:${version}

        docker tag ${ghcr_image}:latest ${docker_hub_image}:latest
        docker push ${docker_hub_image}:latest