Reset or delete existing clusters

Reset clusters with bmctl reset cluster

When a cluster fails to install correctly, you can try to return the nodes to a clean state by resetting the cluster. Resetting a cluster causes it to be deleted. Once deleted, you can re-install the cluster after making any needed configuration changes.

In the context of this document, resetting and deleting are used interchangeably.

Reset self-managed clusters

To reset a cluster that manages itself, such as an admin cluster, issue the following command:

bmctl reset --cluster CLUSTER_NAME

Replace CLUSTER_NAME with the name of the cluster you're resetting.

Reset user clusters

There are two ways to delete or reset user clusters, using bmctl or kubectl respectively. Using bmctl is the recommended way to reset user clusters.

Use bmctl to reset a user cluster

Run the following command to reset a user cluster with bmctl:

bmctl reset --cluster CLUSTER_NAME --admin-kubeconfig ADMIN_KUBECONFIG_PATH

Replace the following:

  • CLUSTER_NAME: the name of the user cluster you're resetting.

  • ADMIN_KUBECONFIG_PATH: the path to the associated admin cluster's kubeconfig file. bmctl supports the use of --kubeconfig as an alias for the--admin-kubeconfig flag.

Use kubectl to delete a user cluster

To use kubectl to delete a user cluster, you must first delete the cluster object, then its namespace. Otherwise, the jobs to reset machines can't be created, and the deletion process might be stuck indefinitely.

To delete a user cluster with kubectl:

  1. Run the following command to delete the cluster object:

    kubectl delete cluster CLUSTER_NAME -n CLUSTER_NAMESPACE \
    --kubeconfig ADMIN_KUBECONFIG_PATH

    Replace the following:

    • CLUSTER_NAME: the name of the user cluster you're deleting.

    • CLUSTER_NAMESPACE: the namespace for the cluster. By default, the cluster namespaces for GKE on Bare Metal are the name of the cluster prefaced with cluster-. For example, if you name your cluster test, the namespace has a name like cluster-test.

    • ADMIN_KUBECONFIG_PATH: the path to the associated admin cluster's kubeconfig file.

  2. After the cluster is deleted successfully, run the following command to delete the namespace:

    kubectl delete namespace CLUSTER_NAMESPACE --kubeconfig ADMIN_KUBECONFIG_PATH

Reset cluster details

Regardless of cluster type, the reset command applies to the entire cluster. There is no option to specify a subset of nodes in a cluster.

Output from the bmctl cluster reset command looks similar to this sample:

bmctl reset --cluster cluster1
Creating bootstrap cluster... OK
Deleting GKE Hub member admin in project my-gcp-project...
Successfully deleted GKE Hub member admin in project my-gcp-project
Loading images... OK
Starting reset jobs...
Resetting: 1    Completed: 0    Failed: 0
...
Resetting: 0    Completed: 1    Failed: 0
Flushing logs... OK

During the reset operation, bmctl first attempts to delete the GKE hub membership registration, and then cleans up the affected nodes. During the reset, storage mounts and data from the anthos-system StorageClass are also deleted.

For all nodes, bmctl runs kubeadm reset, removes the tunnel interfaces used for cluster networking, and deletes the following directories:

  • /etc/kubernetes
  • /etc/cni/net.d
  • /root/.kube
  • /var/lib/kubelet

For load balancer Nodes, bmctl also performs the following actions:

  • Disables keepalived and haproxy services.
  • Deletes the configuration files for keepalived and haproxy.

The bmctl reset command expects the cluster configuration file to be in the current working directory. By default, the path is like the following: bmctl-workspace/CLUSTER_NAME/CLUSTER_NAME.yaml

If you used the --workspacel-dir flag to specify a different directory during cluster creation, you must use the flag to specify the working directory during cluster reset.