Preparing for the Certified Kubernetes Administrator (CKA) exam requires a solid understanding of Kubernetes concepts, practical hands-on experience, and familiarity with the Kubernetes command-line interface. In this post, we’ll provide a series of practice questions designed to help you prepare for the CKA exam by covering key topics such as cluster setup, resource management, troubleshooting, and networking.

CKA Practice Questions

1. Create a Pod

Create a pod named nginx-pod running the nginx container image in the default namespace.

kubectl run nginx-pod --image=nginx

2. Expose a Deployment as a Service

You have a deployment named webapp with 3 replicas. Expose it as a service on port 80.

kubectl expose deployment webapp --type=ClusterIP --port=80

3. Set a Resource Request and Limit

Create a pod named busybox with a container running the busybox image. Ensure it has a CPU request of 100m and a memory limit of 64Mi.

apiVersion: v1
kind: Pod
metadata:
  name: busybox
spec:
  containers:
  - name: busybox
    image: busybox
    resources:
      requests:
        cpu: "100m"
      limits:
        memory: "64Mi"

4. Get the Logs of a Pod

Retrieve the logs of a pod named frontend.

kubectl logs frontend

5. Create a Namespace

Create a namespace named dev.

kubectl create namespace dev

6. Troubleshoot a Failing Pod

A pod named mysql is failing to start. Check its status and identify the issue.

kubectl describe pod mysql
kubectl logs mysql

7. Scale a Deployment

Scale a deployment named api to 5 replicas.

kubectl scale deployment api --replicas=5

8. Create a ConfigMap

Create a ConfigMap named app-config with the key app-name set to my-app.

kubectl create configmap app-config --from-literal=app-name=my-app

9. Apply a Network Policy

Create a NetworkPolicy that allows traffic to a pod labeled app=frontend only from pods in the same namespace labeled app=backend.

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-backend
spec:
  podSelector:
    matchLabels:
      app: frontend
  policyTypes:
  - Ingress
  ingress:
  - from:
    - podSelector:
        matchLabels:
          app: backend

10. Backup and Restore ETCD

Back up the ETCD cluster data and restore it from a backup.

• Backup:

ETCDCTL_API=3 etcdctl snapshot save /path/to/backup.db \
  --endpoints=https://127.0.0.1:2379 \
  --cacert=/etc/kubernetes/pki/etcd/ca.crt \
  --cert=/etc/kubernetes/pki/etcd/server.crt \
  --key=/etc/kubernetes/pki/etcd/server.key

• Restore:

ETCDCTL_API=3 etcdctl snapshot restore /path/to/backup.db

11. Create a PersistentVolumeClaim

Create a PersistentVolumeClaim (PVC) named my-pvc that requests 1Gi of storage from the default storage class.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: my-pvc
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi

12. Set Cluster Autoscaling

Enable horizontal pod autoscaling for a deployment named backend based on CPU usage, setting the target CPU utilization to 75%.

kubectl autoscale deployment backend --cpu-percent=75 --min=1 --max=10

13. Upgrade a Cluster

Simulate upgrading a cluster’s control plane node. Drain the node, perform the upgrade, and mark the node as schedulable.

kubectl drain <node-name> --ignore-daemonsets
# Perform the upgrade
kubectl uncordon <node-name>

14. Debug a Failing Container

Debug a pod named debug-pod that’s stuck in a crash loop by starting a shell in the pod.

kubectl exec -it debug-pod -- /bin/sh

15. Check Node Resources

Get a detailed overview of CPU and memory usage for all nodes in the cluster.

kubectl top nodes

Final Thoughts

These CKA practice questions cover some of the essential tasks you’ll need to master to pass the CKA exam. Practicing these tasks in a real Kubernetes environment will help you gain the confidence and expertise needed to manage Kubernetes clusters effectively. Remember to focus on both understanding the theory behind Kubernetes and getting hands-on experience with cluster management.