CKAD field manual

k8s Namespace YAML example

Almost every exam question is in a namespace. Set it once, then stop forgetting -n.

Create and switch

kubectl create ns app
kubectl config set-context --current --namespace=app
kubectl config view --minify | grep namespace

YAML

apiVersion: v1
kind: Namespace
metadata:
  name: app
  labels:
    env: exam

Inspect

kubectl get ns
kubectl get all -n app
kubectl api-resources --namespaced=true
kubectl api-resources --namespaced=false

Fields

kubectl create ns: Creates the Namespace. It does not switch you into it.
kubectl config set-context: --current --namespace=app. After this, bare kubectl get po is that ns.
kubectl get ns: Namespaces are cluster-scoped. There is no -n on this command.

create ns does not change your context. Default is still default until set-context.
Nodes, PV, Namespace, ClusterRole are cluster-scoped. -n is ignored or rejected.
Deleting a Namespace deletes everything in it. There is no undo.

Official docs Namespaces