After you install the Kubernetes master, you can use the Kubernetes command-line interface, kubectl, to control the Kubernetes cluster. For example, kubectl get cs returns the status of each component. Also, kubectl get nodes returns a list of Kubernetes nodes:

//see the Component Statuses
# kubectl get cs
NAME                 STATUS    MESSAGE              ERROR
controller-manager   Healthy   ok                   nil
scheduler            Healthy   ok                   nil
etcd-0               Healthy   {"health": "true"}   nil


//see the nodes
# kubectl get nodes
NAME          LABELS                           STATUS    AGE
kub-node1   kubernetes.io/hostname=kub-node1   Ready     26d
kub-node2   kubernetes.io/hostname=kub-node2   Ready     26d