Mark node as unschedulable.

 The scheduler stops placing new pods on a cordoned node. Pods that are already
running there are left alone; use "kubectl drain" to move them away as well.
"kubectl get nodes" shows SchedulingDisabled in the STATUS column.

Examples:
  # Stop new pods from landing on node01
  kubectl cordon node01

  # Cordon every node with a label
  kubectl cordon -l disktype=ssd

Options:
    -l, --selector='':
        Cordon the nodes that match this selector.

Usage:
  kubectl cordon NODE [options]
