How to set image spec in template when creating google_cloud_run_service

I am trying to create a google_cloud_run_service through Terraform for an image hosted in Artifact repository. While I am planning to use Terraform for the initial creation, then I am planning to use the cloudbuild.yaml file in the app repo for future builds. I am using the following yaml code in my Terraform file:

resource "google_cloud_run_service" "default" {
  name     = "default-srv"
  location = "us-west2"

  metadata {
    namespace = var.projectId
    annotations = {
      "" = "terraform"

  template {
    spec {
      containers {
        image = ""

This is failing since the service cannot find the image without a tag and I am not sure how to get the newest image from Artifact Repository. I guess I can use the “latest” tag on the image but then I need to keep tag each auto build with latest too is that correct?

Any help/guidance would be appreciated on best practices regarding this.