maybe_build.yaml

name: Check if we need to build a new image due to base image update
on:
  schedule:
    - cron: "30 * * * *"
  workflow_dispatch:

jobs:
  check:
    name: Check if there's a new version of the base image
    runs-on: ubuntu-latest
    outputs:
      needs_rebuild: ${{ steps.maybe-build.conclusion == 'success' }}
    steps:
      - name: Get SHA of the latest base image present in the repository
        id: registry
        run: |
          REGISTRY_SHA=$(skopeo inspect --format '{{ .Digest }}' docker://ghcr.io/ublue-os/aurora-dx:stable )
          echo "SHA=$REGISTRY_SHA" >> $GITHUB_OUTPUT

      - name: Download artifact from the last successful build
        id: last-artifact
        uses: dawidd6/action-download-artifact@v6
        with:
          workflow: build.yaml
          workflow_search: false
          workflow_conclusion: success
          name: latest_base_image_sha
          if_no_artifact_found: ignore

      - name: Get SHA of the base image from the last successful build
        id: last-build
        if: steps.last-artifact.outputs.found_artifact == 'true'
        run: |
          LAST_BUILD_SHA=$(cat latest_base_image_sha)
          echo "SHA=$LAST_BUILD_SHA" >> $GITHUB_OUTPUT

      - name: Output gathered information
        id: debug-output
        run: |
          echo "aurora-dx:stable is currently at [${{ steps.registry.outputs.SHA }}]"
          echo "yaurora has last been built at aurora-dx:stable's: [${{ steps.last-build.outputs.SHA }}]"

      - name: Decide that we need a new build
        id: maybe-build
        if: steps.last-build.outputs.SHA != steps.registry.outputs.SHA
        run: |
          echo "Verdict: yaurora needs to be rebuilt"

  build:
    permissions:
      contents: read
      packages: write
      id-token: write
    name: Build Custom Image
    needs: check
    if: needs.check.outputs.needs_rebuild == 'true'
    uses: ./.github/workflows/build.yaml