name: Publish Docker image for new releases

on:
  release:
    types:
      - published

jobs:
  main:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v1
      - name: Cache Docker layers
        uses: actions/cache@v2
        with:
         path: /tmp/.buildx-cache
         key: ${{ runner.os }}-buildx-${{ github.sha }}
         restore-keys: |
           ${{ runner.os }}-buildx-
      - name: Login to Dockerhub
        uses: docker/login-action@v1
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}
      - name: Build and push
        id:   docker_build
        uses: docker/build-push-action@v2
        with:
          push: true
          file: scripts/docker/release.Dockerfile
          tags: |
            parity/polkadot:latest
            parity/polkadot:${{ github.event.release.tag_name }}
          build-args: |
            POLKADOT_VERSION=${{ github.event.release.tag_name }}
            VCS_REF=${{ github.ref }}
            BUILD_DATE=${{ github.event.release.published_at }}
          cache-from: type=local,src=/tmp/.buildx-cache
          cache-to: type=local,dest=/tmp/.buildx-cache
      - name: Image digest
        run: echo ${{ steps.docker_build.outputs.digest }}
