You can import an existing Kubernetes cluster and then manage it using Rancher.

Prerequisites:

  • If your existing Kubernetes cluster already has a cluster-admin role defined, you must have this cluster-admin privilege to import the cluster into Rancher. In order to apply the privilege, you need to run kubectl create clusterrolebinding cluster-admin-binding --clusterrole cluster-admin --user [USER_ACCOUNT] before running the kubectl command to import the cluster.
  • By default, GKE users are not given this privilege, so you will need to run the command before importing GKE clusters. To learn more about GKE RBAC, please click here.
  1. From the Clusters page, click Add Cluster.

  2. Choose Import.

  3. Enter a Cluster Name.

  4. Use Member Roles to configure user authorization for the cluster.

    • Click Add Member to add users that can access the cluster.
    • Use the Role drop-down to set permissions for each user.

  5. Click Create.

  6. Copy the first command displayed to your clipboard.

  7. Log into one of your cluster nodes using your preferred shell, such as PuTTy or a remote Terminal connection. Run the command copied to your clipboard.

  8. If you receive a message of certificate signed by unknown authority, copy the second command displayed in Rancher to your clipboard. Then run the command on your cluster node.

  9. When you finish running the command(s) on your Linux host(s), click Done.

Result:

  • Your cluster is created and assigned a state of Provisioning. Rancher is standing up your cluster.
  • You can access your cluster after its state is updated to Active.
  • Active clusters are assigned a Project and Namespace, both of which are named Default.

Note: You can not re-import a cluster that is currently active in a Rancher setup.