action.yml

name: Build and Push Docker Image

description: A reusable GitHub Action to build and push Docker images to GitHub packages.

inputs:
  image_name:
    description: 'The name of the Docker image. If left off, the repository name is used.'
    required: false
    type: string
  image_dir:
    description: 'The directory containing Docker build files. If left off, . (the base repository level) is used.'
    required: false
    type: string
  github_token:
    description: 'GitHub token for authentication. Optional.'
    required: true
    type: string
    
runs:
  using: "composite"
  steps:
    - name: Check out the repository
      uses: actions/checkout@v3

    - name: Log in to GitHub Container Registry
      uses: docker/login-action@v1
      with:
        registry: ghcr.io
        username: ${{ github.actor }}
        password: ${{ inputs.github_token }}

    - name: Set Image Name and Directory
      id: setup
      shell: bash
      run: |
        # Default image name to repository name if not provided
        if [ -z "${{ inputs.image_name }}" ]; then
          echo "name=${{ github.event.repository.name }}" >> $GITHUB_ENV
        else
          echo "name=${{ inputs.image_name }}" >> $GITHUB_ENV
        fi

        # Default image directory to current directory if not provided
        if [ -z "${{ inputs.image_dir }}" ]; then
          echo "dir=." >> $GITHUB_ENV
        else
          echo "dir=${{ inputs.image_dir }}" >> $GITHUB_ENV
        fi

    - name: Extract VERSION from Dockerfile
      id: get_version
      shell: bash
      run: |
        # Check for both OCI-compliant version label and generic version label
        if grep -q "LABEL org.opencontainers.image.version=" ${{ env.dir }}/Dockerfile; then
          version=$(grep "LABEL org.opencontainers.image.version=" ${{ env.dir }}/Dockerfile | cut -d '=' -f 2 | tr -d ' ')
        elif grep -q "LABEL VERSION=" ${{ env.dir }}/Dockerfile; then
          version=$(grep "LABEL VERSION=" ${{ env.dir }}/Dockerfile | cut -d '=' -f 2 | tr -d ' ')
        else
          version=""
        fi
        echo "version=${version}" >> $GITHUB_ENV
        
        # Always create a short SHA for tagging
        short_sha=$(echo "${{ github.sha }}" | cut -c1-7)
        echo "tag=${short_sha}" >> $GITHUB_ENV

    - name: Build the Docker image
      shell: bash
      run: |
        # Build the Docker image with both tags
        docker build ${{ env.dir }} \
          -f ${{ env.dir }}/Dockerfile \
          --tag ghcr.io/${{ github.repository_owner }}/${{ env.name }}:${{ env.tag }} \
          --tag ghcr.io/${{ github.repository_owner }}/${{ env.name }}:latest
        
        # If VERSION exists, tag the image with that as well
        if [ -n "${{ env.version }}" ]; then
          docker tag ghcr.io/${{ github.repository_owner }}/${{ env.name }}:${{ env.tag }} ghcr.io/${{ github.repository_owner }}/${{ env.name }}:${{ env.version }}
        fi

    - name: Push the Docker image
      shell: bash
      run: |
        docker push ghcr.io/${{ github.repository_owner }}/${{ env.name }}:${{ env.tag }}
        docker push ghcr.io/${{ github.repository_owner }}/${{ env.name }}:latest
        
        # Push the version tag if it exists
        if [ -n "${{ env.version }}" ]; then
          docker push ghcr.io/${{ github.repository_owner }}/${{ env.name }}:${{ env.version }}
        fi