main.yml

name: Docker image CI

on:
  push:
    # takes muliple branch names
    branches: 
      - master
      - '[0-9][0-9][0-9][0-9].[0-9][0-9].*' # 2021.01.01
  
env:
  IMAGE_TAG: latest
  REPO_URL: ${{ github.repository }}
    
jobs:
  build:
    # to test a feature, change the repo name to your github id
    if: github.repository_owner == 'tl-its-umich-edu'
    runs-on: ubuntu-latest
    steps:
  
      - name: Checkout code 
        uses: actions/checkout@v3
    
      - name: Extract branch name
        id: extract_branch
        run: echo "BRANCH_NAME=$(basename ${{ github.ref }})" >> $GITHUB_ENV
      
      - name: build Docker image
        run: |
          docker build . --tag ghcr.io/${{ env.REPO_URL }}:${{ env.IMAGE_TAG }}-${BRANCH_NAME}
      
      - name: Login to GitHub Container Registry
        uses: docker/login-action@v2
        with:
            registry: ghcr.io
            username: ${{ github.actor }}
            password: ${{ secrets.GITHUB_TOKEN }}
      
      - name: Push Docker image to GitHub Container Registry
        run: |
          docker push ghcr.io/${{ env.REPO_URL }}:${{ env.IMAGE_TAG }}-${BRANCH_NAME}