custom-containers/.github/workflows/build.yml

name: Docker Build and Publish

on:
  push:
    paths:
      - "**/Containerfile"

jobs:
  build_and_publish:
    name: Build and Publish Docker Image
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v2

      - name: Get Dockerfile image name
        id: get_image_name
        run: |
          IMAGE_NAME=$(grep -Po '(?<=name=")[^"]*' Containerfile)
          echo "::set-output name=image_name::$IMAGE_NAME"

      - name: Login to container registry
        run: docker login -u ${{ secrets.REGISTRY_USERNAME }} -p ${{ secrets.REGISTRY_PASSWORD }} scm.wyattjmiller.com

      - name: Check for Dockerfile changes
        id: dockerfile_changed
        run: |
          if git diff --name-only ${{ github.event.before }} ${{ github.sha }} | grep '^Containerfile$'; then
            echo "::set-output name=changed::true"
          else
            echo "::set-output name=changed::false"
          fi

      - name: Build and Publish Docker image
        if: steps.dockerfile_changed.outputs.changed == 'true'
        run: |
          docker build -t scm.wyattjmiller.com/${{ steps.get_image_name.outputs.image_name }}:${{ github.sha }} .
          docker push scm.wyattjmiller.com/${{ steps.get_image_name.outputs.image_name }}:${{ github.sha }}