GkeCluster contains information specific to GKE clusters.
If cluster_missing is set then it denotes that the GKE cluster no longer exists in the GKE Control Plane.
Immutable. Self-link of the GCP resource for the GKE cluster. For example: //container.googleapis.com/projects/my-project/locations/us-west1-a/clusters/my-cluster Zonal clusters are also supported.