Kubernetes Application Developer CKAD Full Course Free

Below is an exam-style, step-by-step solution (commands + verification). Follow exactly on host ckad000.

0) Connect to the right host

ssh ckad000

(Optional but good sanity check)

kubectl config current-context

kubectl get ns

1) Inspect the existing Deployment (to know its labels/ports)

kubectl -n prod get deploy nginx-deployment

kubectl -n prod get deploy nginx-deployment -o wide

Check what labels the Pod template already has (important for the Service selector):

kubectl -n prod get deploy nginx-deployment -o jsonpath='{.spec.template.metadata.labels}{"\n"}'

Check container ports (so we expose the correct targetPort):

kubectl -n prod get deploy nginx-deployment -o jsonpath='{.spec.template.spec.containers[0].ports}{"\n"}'

If ports output is empty, it’s still often nginx on 80, but the safest is to confirm by describing a pod later.

2) Update Deployment to 2 replicas

Fastest:

kubectl -n prod scale deploy nginx-deployment --replicas=2

Verify:

kubectl -n prod get deploy nginx-deployment

3) Add label role=webFrontEnd to the Pod (Pod template label)

You must add it under:

spec.template.metadata.labels

Use a patch (quick + safe):

kubectl -n prod patch deploy nginx-deployment \

-p '{"spec":{"template":{"metadata":{"labels":{"role":"webFrontEnd"}}}}}'

Verify the Deployment template now includes it:

kubectl -n prod get deploy nginx-deployment -o jsonpath='{.spec.template.metadata.labels}{"\n"}'

Now verify the running Pods have the label (important!):

kubectl -n prod get pods --show-labels

If the label doesn’t show on pods immediately, wait for rollout:

kubectl -n prod rollout status deploy nginx-deployment

kubectl -n prod get pods --show-labels

4) Create a NodePort Service rover exposing the Deployment’s Pods

4.1 Get a reliable target port

Try to read containerPort:

kubectl -n prod get deploy nginx-deployment -o jsonpath='{.spec.template.spec.containers[0].ports[0].containerPort}{"\n"}'

If this prints a number (commonly 80), use it as --target-port.

If it prints nothing/empty, check a pod:

POD=$(kubectl -n prod get pod -l role=webFrontEnd -o jsonpath='{.items[0].metadata.name}')

kubectl -n prod describe pod "$POD" | sed -n '/Containers:/,/Conditions:/p' | sed -n '/Ports:/,/Environment:/p'

Assuming nginx is on 80 (most common), create the service:

kubectl -n prod expose deploy nginx-deployment \

--name=rover \

--type=NodePort \

--port=80 \

--target-port=80

If your nginx container port is different (e.g., 8080), change --target-port=8080 accordingly.

5) Verify Service + endpoints (critical)

kubectl -n prod get svc rover -o wide

kubectl -n prod describe svc rover

kubectl -n prod get endpoints rover -o wide

You should see 2 endpoints (matching 2 pods).

Also confirm the pods are Ready:

kubectl -n prod get pods -l role=webFrontEnd -o wide

Quick “CKAD checkpoints”

Deployment in prod has replicas=2

Pod template has label role=webFrontEnd

Service rover in prod is NodePort

Service endpoints point to the nginx pods

To find the broken pod and store its name and namespace to /opt/KDOB00401/broken.txt, you can use the kubectl get pods command and filter the output by the status of the pod.

kubectl get pods --field-selector=status.phase=Failed -o jsonpath='{.items[*].metadata.namespace}/{.items[*].metadata.name}' > /opt/KDOB00401/broken.txt

This command will list all pods with a status of Failed and output their names and namespaces in the format /. The output is then written to the /opt/KDOB00401/broken.txt file.

To store the associated error events to a file /opt/KDOB00401/error.txt, you can use the kubectl describe command to retrieve detailed information about the pod, and the grep command to filter the output for error events.

kubectl describe pods --namespace | grep -i error -B5 -A5 > /opt/KDOB00401/error.txt

Replace and with the name and namespace of the broken pod you found in the previous step.

This command will output detailed information about the pod, including error events. The grep command filters the output for lines containing "error" and also prints 5 lines before and after the match.

To fix the issue, you need to analyze the error events and find the root cause of the issue.

It could be that the application inside the pod is not running, the container image is not available, the pod has not enough resources, or the liveness probe configuration is incorrect.

Once you have identified the cause, you can take appropriate action, such as restarting the application, updating the container image, increasing the resources, or modifying the liveness probe configuration.

After fixing the issue, you can use the kubectl get pods command to check the status of the pod and ensure