Unregistering a cluster

This page describes how to manually unregister a cluster from a Google Cloud fleet. When you manually unregister a cluster, its connection to the fleet is removed but the cluster remains. Deleting a registered GKE cluster on Google Cloud using either the Google Cloud console or gcloud CLI also deletes the cluster's fleet membership.

You can unregister GKE clusters on Google Cloud and attached third-party clusters only. Other cluster types can't be unregistered.

Note that moving registered clusters between fleets (unregistering then reregistering) is not recommended, as it can result in unexpected or unwanted behavior: for example, your workloads' fleet Workload Identity will change, potentially resulting in blocked requests and outages. The recommended approach is to create a new cluster in the fleet in which you want your workloads to reside, then move your workloads from your old cluster to the new cluster.

Unregister a cluster

gcloud

Unregister a GKE cluster

This command can only be used to unregister GKE clusters registered using gcloud container clusters update or gcloud container clusters create.

Run the following command:

gcloud container clusters update CLUSTER_NAME --clear-fleet-project

Replace CLUSTER_NAME with the cluster's name you want to delete.

Unregister a GKE cluster (legacy command)

If you registered a cluster using the older register command, run either of the following commands to unregister it:

gcloud container fleet memberships unregister [MEMBERSHIP_NAME] \
   --project=[PROJECT_ID] \
   --gke-uri=[GKE_URI]

gcloud container fleet memberships unregister [MEMBERSHIP_NAME] \
   --project=[PROJECT_ID] \
   --gke-cluster=[GKE_CLUSTER]

where:

[PROJECT_ID] is your Google Cloud project ID. Learn how to find this value.
[MEMBERSHIP_NAME] is the membership name that corresponds to your cluster. To list all the memberships on the Hub, run: gcloud container fleet memberships list.
[GKE_URI] is the URI of the GKE cluster, for example: 'https://container.googleapis.com/projects/my-project/locations/us-central1-a/clusters/my-cluster'. You can obtain the URI by running gcloud container clusters list --uri. The provided URI will be validated to confirm that it maps to the valid GKE cluster.
[GKE_CLUSTER] is the location/name of the GKE cluster. The location can be a zone or a region for example: us-central1-a/my-cluster.

Unregister an attached cluster

These instructions apply to clusters registered using the latest version of our attached clusters feature. Clusters attached using the deprecated previous generation of this feature should use the legacy command in the next section.

Unregister an attached cluster (legacy command)

If you registered a cluster using the previous generation of attached clusters, run the following command to unregister it:

gcloud container fleet memberships unregister [MEMBERSHIP_NAME] \
   --project=[PROJECT_ID] \
   --context=[KUBECONFIG_CONTEXT] \
   --kubeconfig=[KUBECONFIG_PATH]

where:

[PROJECT_ID] is your Google Cloud project ID. Learn how to find this value.
[MEMBERSHIP_NAME] is the membership name that corresponds to your cluster. To get list of all the memberships on the Hub, run: gcloud container fleet memberships list.
[KUBECONFIG_PATH] is the local path where your kubeconfig containing an entry for the cluster file is stored. This defaults to $KUBECONFIG if that environment variable is set, otherwise this defaults to $HOME/.kube/config.
[KUBECONFIG_CONTEXT] is the cluster's context as it appears in the kubeconfig file. You can get this value from the command line by running kubectl config current-context.

Console

Unregister a GKE cluster on Google Cloud

To unregister a GKE cluster:

Go to the GKE Clusters page. This page shows all your clusters.

Go to the GKE Clusters page
Click Actions next to the cluster in the list that you want to unregister.
In the Actions menu, select Unregister.
In the dialog that displays, type the name of the cluster and click Unregister to confirm the action.

Unregister an attached third-party cluster

To unregister an attached cluster:

In the Google Cloud console, go to the Google Kubernetes Engine clusters overview page.

Go to GKE clusters
Select the Google Cloud project that the cluster is in.
Click the name of the cluster you want to detach, and then select View more details in the side panel.
Near the top of the window, click Delete.
When prompted to confirm, enter the name of the cluster and click Confirm.

Terraform

To unregister a GKE cluster that you registered using Terraform:

Delete the following block from the google_container_cluster resource configuration of the cluster:

fleet {
      project = "FLEET_HOST_PROJECT""
    }

FLEET_HOST_PROJECT is the Google Cloud project ID your cluster is registered to.

Manage the Connect Agent

The following steps apply only to unregistering attached clusters, where the Connect Agent is installed on the cluster as part of registration.

Optional: Verify that the Connect Agent namespace is deleted

After you unregister a cluster, you can verify that the namespace used by the Connect Agent has been deleted. This applies to registrations that install the Connect Agent only. To do so, run:

kubectl get ns -l hub.gke.io/project

If this command returns no output, the namespace has already been deleted.

Delete the Connect Agent Service Account

If you created a service account for the Connect Agent, you can delete it as follows:

gcloud iam service-accounts delete [SERVICE_ACCOUNT_NAME]

Unregister an unavailable cluster

If you want to unregister a cluster that you can no longer access, perform the following steps:

List the clusters (a.k.a memberships) that are currently registered:
```
gcloud container fleet memberships list
```
In the command output, the Name column lists the membership names of registered clusters, and the EXTERNAL_ID column lists the clusters' UIDs of the kube-system namespace.
To unregister an unavailable cluster, run the following command:
```
gcloud container fleet memberships delete [MEMBERSHIP_NAME]
```
where [MEMBERSHIP_NAME] is the membership name that corresponds to your cluster.