name: Build and publish Runner API
on:
  push:
    branches:
      - main
env:
  IMAGE: eu.gcr.io/slam-lang/slam-runner-api
jobs:
  build-and-publish:
    runs-on: ubuntu-latest
    steps:
      - id: checkout
        uses: actions/checkout@v2

      - name: "Compute new image tag"
        run: |
          echo "Long commit SHA: ${GITHUB_SHA}"
          export TAG=$(echo "${GITHUB_SHA}" | head -c 7)
          echo "TAG: ${TAG}"
          echo "TAG=${TAG}" >> ${GITHUB_ENV}

      - id: "auth"
        uses: "google-github-actions/auth@v0"
        with:
          credentials_json: "${{ secrets.GCP_CREDENTIALS }}"

      - name: "Set up Cloud SDK"
        uses: "google-github-actions/setup-gcloud@v0"

      - name: Build and tag
        run: |
          gcloud auth configure-docker --quiet
          if docker pull "${IMAGE}:latest"; then
            docker build -t "${IMAGE}:${TAG}" --cache-from="${IMAGE}:latest" .
          else
            docker build -t "${IMAGE}:${TAG}" .
          fi
          docker tag "${IMAGE}:${TAG}" "${IMAGE}:latest"

      - name: Publish
        run: |
          docker push "${IMAGE}:${TAG}"
          docker push "${IMAGE}:latest"
          echo "Published ${IMAGE}:${TAG}"