main.yml

name: Validate Configuration and Build Docker image

on:
  push:
    tags:
      - '*'

jobs:
  build_docker_image_and_validate:
    runs-on: ubuntu-latest
    container:
      image: docker:20
    permissions:
      packages: write
      contents: read
    env:
      CI_REGISTRY_USER: ${{ github.actor }}
      CI_REGISTRY_PASSWORD: ${{ secrets.GITHUB_TOKEN }}
      CI_REGISTRY: ghcr.io
      CI_REGISTRY_IMAGE: ghcr.io/${{ github.repository }}
    steps:
      - uses: actions/checkout@v3
      - name: Verify Tag Format
        run: |
          echo $GITHUB_REF_NAME | grep -oE '^([0-9]+\.){2}[0-9]+$' || (echo "ERROR: Invalid tag format, should be a three part version number (e.g. 1.2.3)" && exit 1)
      - name: Build Docker Image
        run: |
          IMAGE_TAG=$(echo "$CI_REGISTRY_IMAGE:$GITHUB_REF_NAME" | tr [:upper:] [:lower:])
          docker build . -t $IMAGE_TAG
      - name: Validate Configuration
        run: |
          IMAGE_TAG=$(echo "$CI_REGISTRY_IMAGE:$GITHUB_REF_NAME" | tr [:upper:] [:lower:])
          docker run --rm $IMAGE_TAG python validate.py
      - name: Push Docker Image
        run: |
          IMAGE_TAG=$(echo "$CI_REGISTRY_IMAGE:$GITHUB_REF_NAME" | tr [:upper:] [:lower:])
          echo $CI_REGISTRY_PASSWORD | docker login -u $CI_REGISTRY_USER $CI_REGISTRY --password-stdin
          if docker pull $IMAGE_TAG > /dev/null 2>&1; then echo "ERROR: An image with the given tag already exists. Please increment the contents of the VERSION file" && exit 1; fi
          docker push $IMAGE_TAG
    timeout-minutes: 5