patch

$ kubectl patch (-f FILENAME | TYPE NAME) -p PATCH

$ kubectl get deployments

NAME    READY   UP-TO-DATE   AVAILABLE   AGE
nginx   2/2     2            2           24m

kubectl patch deployment nginx -p '{"spec":{"replicas":1}}'

deployment.apps/nginx patched

$ kubectl get deployments

NAME    READY   UP-TO-DATE   AVAILABLE   AGE
nginx   1/1     1            1           26m

# Partially update a node using a strategic merge patch. Specify the patch as JSON.
kubectl patch node k8s-node-1 -p '{"spec":{"unschedulable":true}}'

# Partially update a node using a strategic merge patch. Specify the patch as YAML.
kubectl patch node k8s-node-1 -p $'spec:\n unschedulable: true'

# Partially update a node identified by the type and name specified in "node.json" using strategic merge patch.
kubectl patch -f node.json -p '{"spec":{"unschedulable":true}}'

# Update a container's image; spec.containers[*].name is required because it's a merge key.
kubectl patch pod valid-pod -p '{"spec":{"containers":[{"name":"kubernetes-serve-hostname","image":"new image"}]}}'

# Update a container's image using a json patch with positional arrays.
kubectl patch pod valid-pod --type='json' -p='[{"op": "replace", "path": "/spec/containers/0/image", "value":"newimage"}]'

---