Delete a Kubernetes cluster

Kubernetes cluster deletion unregisters the cluster from the Google Distributed Cloud (GDC) air-gapped instance and deletes the workloads, node pools, control plane nodes, and corresponding resources.

Before you begin

To get the permissions needed to delete a Kubernetes cluster, ask your Organization IAM Admin to grant you the User Cluster Admin role (user-cluster-admin). This role is not bound to a namespace.

Delete a Kubernetes cluster and its resources

Complete the following steps to delete a Kubernetes cluster and its resources:

Console

In the navigation menu, select Kubernetes Engine > Clusters.
In the cluster list, click the cluster that you want to delete.
Click delete Delete Cluster.
When prompted, type the given confirmation phrase and click Delete to delete the cluster.

`kubectl`

Pause the reconciliation for the Cluster custom resource of the Kubernetes cluster:

kubectl annotate clusters.cluster.gdc.goog/KUBERNETES_CLUSTER_NAME -n platform \
    cluster.gdc.goog/paused=true --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG

Trigger the deletion of the Cluster custom resource of the cluster:

kubectl delete clusters.cluster.gdc.goog/KUBERNETES_CLUSTER_NAME -n platform \
    --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG --wait=false

Trigger the deletion of all NodePoolClaim custom resources in the cluster:
```
kubectl delete --all nodepoolclaims -n NAMESPACE \
    --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG --wait=false
```
This command starts the background deletion of all node pool claims in the cluster.
Delete the Cluster custom resource of the cluster:
```
kubectl delete clusters KUBERNETES_CLUSTER_NAME \
    -n NAMESPACE --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG
```
This command might take several minutes based on the amount of node pools in the cluster to delete.

Delete the namespace custom resource:

kubectl --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG delete namespace NAMESPACE

Delete the Istio secret in the istio-system namespace:

kubectl delete secrets istio-remote-secret-KUBERNETES_CLUSTER_NAME -n istio-system \
    --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG

In some cases, your Istio secret might have a different name. To list your Istio secret and confirm the name, run the following command:

kubectl get secrets -n istio-system \
    --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG

Remove the address pool claims with the same name as the target Kubernetes cluster, but located in different namespaces:
```
for j in $(kubectl get addresspoolclaims -A -o custom-columns=:.metadata.namespace --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG);
do
kubectl delete addresspoolclaims KUBERNETES_CLUSTER_NAME -n $j --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG;
done
```
You can expect to see errors like the following after executing this command:
```
Error from server (NotFound): addresspoolclaims.system.private.gdc.goog "KUBERNETES_CLUSTER_NAME" not found
```
Ignore these errors. The command attempts to find all address pool claims with the specified cluster name in all namespaces. Some namespaces don't contain address pool claims with the name, resulting in an error.
Verify that you deleted the namespace of the Kubernetes cluster:
```
kubectl get namespaces NAMESPACE \
    --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG
```
If the namespace is deleted, the output displays an error indicating the namespace is not found. For example:
```
Error from server (NotFound): namespaces NAMESPACE not found
```

Unpause the reconciliation for the Cluster custom resource of the cluster:

kubectl annotate clusters.cluster.gdc.goog/KUBERNETES_CLUSTER_NAME -n platform \
    cluster.gdc.goog/paused- --kubeconfig=ORG_ADMIN_CLUSTER_KUBECONFIG

API

To delete a Kubernetes cluster, remove the Cluster custom resource from the GDC instance:
```
kubectl delete clusters.cluster.gdc.goog/KUBERNETES_CLUSTER_NAME -n platform \
    --kubeconfig ORG_ADMIN_CLUSTER_KUBECONFIG
```
Note: The deletion can take up to 20 minutes. If you want the deletion process to run in the background, append the --wait=false parameter to the command.

Replace the following:
- KUBERNETES_CLUSTER_NAME: The name of the cluster to delete.
- ORG_ADMIN_CLUSTER_KUBECONFIG: The org admin cluster's kubeconfig path.

Terraform

To delete a Kubernetes cluster using Terraform, run:

terraform destroy -target kubernetes_manifest.cluster-create