check-sha.yml

name: Check Commit SHA

on: 
  push:
    branches: [main]
    paths-ignore:
      - 'README.md'
      - 'LICENSE'
      - 'garbage.txt'
  schedule:
    # 12:34 AM every day
    - cron: '34 0 * * *'

jobs:
  get-latest-commit:
    runs-on: ubuntu-latest
    outputs:
      latest-sha: ${{ steps.get-latest-sha.outputs.result }}
      new-commit: ${{ steps.compare-sha.outputs.NEWCOMMIT }}
    steps:       
      - name: Get latest commit SHA
        id: get-latest-sha
        uses: actions/github-script@v6
        with:
          github-token: ${{ secrets.TOKEN_FOR_ACTIONS }}
          result-encoding: string
          script: |
            const commits = await github.rest.repos.listCommits({
              owner: 'docker-library',
              repo: 'official-images'
            });
            return commits.data[0].sha;

      - name: Compare SHAs
        id: compare-sha
        run: |
          echo Archived SHA: ${ARCHIVEDSHA}
          echo Latest SHA:   ${LATESTSHA}
          if [[ $ARCHIVEDSHA == $LATESTSHA ]]; then 
            NEWCOMMIT=false       
          else
            NEWCOMMIT=true
          fi

          echo "NEWCOMMIT=$NEWCOMMIT" >> $GITHUB_OUTPUT
          echo "NEWCOMMIT=$NEWCOMMIT"
        env:
          ARCHIVEDSHA: ${{ vars.DOCKER_LIBRARY_SHA }}
          LATESTSHA: ${{ steps.get-latest-sha.outputs.result }}

  trigger-build:
    if: needs.get-latest-commit.outputs.new-commit == 'true' || startsWith(github.event.head_commit.message, 'FORCE_BUILD=TRUE')
    needs: get-latest-commit
    name: Store docker-library commit SHA    
    uses: ./.github/workflows/build.yml
    secrets: inherit