# check kubernetes API health endpoints
kubectl get --raw='/readyz?verbose'
# list node labels
kubectl get nodes --show-labels
# label a node
kubectl label nodes <my-node-name> disktype=ssd
# label a namespace
kubectl label namespace <my-namespace> istio-injection=enabled
kubectl label namespace <my-namespace> istio-injection=enabled --overwrite
# patch a persistentVolumeReclaimPolicy value on a PV from Delete to Retain
kubectl patch pv pvc-3e953bf9-25c4-499d-ae09-d23d0f9f6c44 -p '{"spec":{"persistentVolumeReclaimPolicy":"Retain"}}'
# to mark a Node unschedulable
kubectl cordon <my-node>
# to unmark a Node unschedulable
kubectl uncordon <my-node>