name: Docker Publish

on:
  push:
    tags: [ 'v*.*.*' ]

env:
  IMAGE_NAME: mjt128/scryer-prolog

jobs:
  build:

    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v3

      # Workaround: https://github.com/docker/build-push-action/issues/461
      - name: Setup Docker buildx
        uses: docker/setup-buildx-action@79abd3f86f79a9d68a23c75a09a9a85889262adf

      # Login against Docker registry
      # https://github.com/docker/login-action
      - name: Log into registry
        uses: docker/login-action@28218f9b04b4f3f62068d7b6ce6ca5b26e35336c
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      # Extract Docker image tag from git tag. E.g. if git tag is "v0.19.1" then use 
      # Docker image tag "0.19.1". Tag "latest" is automatically synced with newest
      # version.
      # https://github.com/docker/metadata-action
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@98669ae865ea3cffbcbaa878cf57c20bbf1c6c38
        with:
          images: docker.io/${{ env.IMAGE_NAME }}
          tags: |
            type=semver,pattern={{version}}

      # Build and push Docker image with Buildx
      # https://github.com/docker/build-push-action
      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@ad44023a93711e3deb337508980b4b5e9bcdc5dc
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}