I’ve created GitHub Actions workflow that build and push docker images to Artifact Registry with docker/build-push-action and deploy to Cloud Run.
This is my Artifact Registry. The tagged package is deployed to Cloud Run.

Does anyone have a good idea to delete all unused or unreferred images in Artifact Registry in GitHub Actions?
I can delete them by hand on console or GCP web console, but I wanna automate it.

My idea was to list all images except those tagged “${GITHUB_SHA}”, sorted by updated and delete them after tagged image appear.

gcloud container images list-tags "${BASE_IMAGE}" 
  --filter="NOT tags:${GITHUB_SHA}" --format="table(digest, tags)" | 
  tail -n +2 | 
  while read row
  do
    arr=($row)
    if [ ${#arr[@]} -eq 2 ]; then
      start="true"
    fi

    if [[ -v start ]]; then
      digest=${arr[0]}
      gcloud container images delete -q --force-delete-tags "${BASE_IMAGE}@sha256:$digest"
    fi
  done

But I couldn’t list sorted by updated because all layer-cache images’ timestamp are UNIX epoch (1970/01/01 00:00:00).
Docker Image Timestamp Issue
So sometimes gcloud container images delete try to delete not-unreferred images and GitHub Actions workflow fails with this error.

Manifest is still referenced by one or more parent images: ocarry-api/manifests/sha256:93eec65fc56910c8c8012a385e7769fae87885f6459bc8e1613855730ef07007: None

this is my part of GitHub Actions yaml

      - name: Build and push
        id: docker-build
        uses: docker/build-push-action@v6
        with:
          platforms: linux/amd64
          context: .
          push: true
          tags: ${{ env.IMAGE }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
      - name: Deploy to Cloud Run
        id: deploy
        uses: google-github-actions/deploy-cloudrun@v2
        with:
          service: /* my service id */
          image: ${{ env.IMAGE }}
          region: ${{ env.GCP_REGION }}
      - name: Clean up Container images
        run: |
          gcloud container images list-tags "${BASE_IMAGE}" 
          /* the shell script above continues */