publish_docker.yml

name: Publish Docker image to GitHub Package Registry
on: 
  push:
    branches: master
  pull_request:
    branches: master
jobs:
  build:
    runs-on: ubuntu-latest 
    
    steps:
    - name: Get docker tag
      id: tag
      run: |
        MYTAG=$(echo $GITHUB_REF | sed -e 's#refs/heads/master#latest#' | sed -e 's#refs/pull/\([^/]*\)/.*#pr_\1#')
        echo "MYTAG=$MYTAG"
        echo "::set-output name=DOCKER_TAG::$MYTAG"
      env:
        GITHUB_REF: ${{ github.ref }}
        
    - name: Copy Repo Files
      uses: actions/checkout@v2
                 
     #This Action Emits 2 Variables, IMAGE_SHA_NAME and IMAGE_URL 
     #which you can reference in subsequent steps
    - name: Publish Docker Image to GPR
      uses: machine-learning-apps/gpr-docker-publish@master
      id: docker
      with:
        IMAGE_NAME: 'lindat-billing'
        TAG: ${{ steps.tag.outputs.DOCKER_TAG }}
        DOCKERFILE_PATH: 'Docker/frontend/Dockerfile'
        BUILD_CONTEXT: './'
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}