CKA Quick Review Notes

Deployment with Startup Delay

When a Pod must wait before the main application starts, use an initContainer.

spec:
  initContainers:
  - name: init-deploy
    image: busybox
    command:
    - sleep
    - "30"

  containers:
  - name: nginx
    image: nginx

Persistent Volume (HostPath)

CKA Mental Model:

PersistentVolume
├─ capacity
├─ accessModes
└─ hostPath

Example:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: lab154
spec:
  capacity:
    storage: 2Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: /lab154

spec:
  volumes:

spec:
  hostPath:
    path: /lab154

NodePort Service

Task Example:

Create a deployment running nginx that can be accessed externally on port 32567 on every cluster node.

Creation workflow:

kubectl create deployment lab155deploy --image=nginx
kubectl scale deployment lab155deploy --replicas=3

Create Service:

kubectl expose deployment lab155deploy \
  --type=NodePort \
  --port=80

Edit service YAML and specify:

spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 80
    nodePort: 32567

Useful Exam Commands

kubectl explain pv.spec

kubectl explain deployment.spec.template.spec

kubectl explain deployment.spec.template.spec.initContainers

kubectl get pv

kubectl get svc

kubectl describe pv lab154

kubectl describe svc lab155deploy

Exam Strategy

• Do not memorize full YAML manifests.
• Memorize resource structure.
• Use kubectl explain when stuck.
• Verify with kubectl get and kubectl describe.
• The cluster is the final judge.