name: Publish Docker image

on:
  workflow_dispatch:
  push:
    # Publish `master` branch as Docker `latest` image.
    branches:
      - master
    paths:
    - 'Dockerfile'
    - 'lib/**'
    - 'server/**'
    - '.github/workflows/docker.yml'
  # Publish `v0.1.2` release as image tag `0.1.2`.
  release:
    types: [published]

jobs:
  build-and-publish:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          submodules: 'recursive'

      - name: Login to GitHub Container Registry
        uses: docker/login-action@v1
        with:
          registry: ghcr.io
          username: ${{github.actor}}
          password: ${{secrets.GITHUB_TOKEN}}

      - name: Generate image ID and version
        run: |
          IMAGE_ID=ghcr.io/${{ github.repository_owner }}/oxigraph
          # Change all uppercase to lowercase
          IMAGE_ID=$(echo $IMAGE_ID | tr '[A-Z]' '[a-z]')
          # Strip git ref prefix from version
          VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
          # Strip "v" prefix from tag name
          [[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION | sed -e 's/^v//')
          # Use Docker `latest` tag convention
          [ "$VERSION" == "master" ] && VERSION=latest
          echo "IMAGE_ID=$IMAGE_ID" >> $GITHUB_ENV
          echo "VERSION=$VERSION" >> $GITHUB_ENV

      - name: Build docker image
        run: |
          docker build -t $IMAGE_ID:$VERSION .

      - name: Push docker image
        run: |
          docker push $IMAGE_ID:$VERSION