name: Delete GCP resources

on:
  schedule:
    - cron: "0 0 1 * *"
  workflow_dispatch:

jobs:
  delete-resources:
    name: Delete old GCP resources
    runs-on: ubuntu-latest
    permissions:
      contents: 'read'
      id-token: 'write'
    steps:
      # Setup gcloud CLI
      - name: Authenticate to Google Cloud
        id: auth
        uses: google-github-actions/auth@v0.8.0
        with:
          retries: '3'
          workload_identity_provider: 'projects/143793276228/locations/global/workloadIdentityPools/github-actions/providers/github-oidc'
          service_account: 'github-service-account@zealous-zebra.iam.gserviceaccount.com'
          token_format: 'access_token'

      # Deletes all the instances template older than 30 days
      - name: Delete old instance templates
        run: |
          TEMPLATES=$(gcloud compute instance-templates list --sort-by=creationTimestamp  --filter="creationTimestamp < $(date --date='30 days ago' '+%Y%m%d')" --format='value(NAME)')

          for TEMPLATE in $TEMPLATES
          do
            gcloud compute instance-templates delete ${TEMPLATE} --quiet || continue
          done