The Certified Kubernetes Application Developer (CKAD) Program (CKAD)

Solution:

To deploy the counter pod to the cluster using the provided YAML spec file, you can use the kubectl apply command. The apply command creates and updates resources in a cluster.

kubectl apply -f /opt/KDOB00201/counter.yaml

This command will create the pod in the cluster. You can use the kubectl get pods command to check the status of the pod and ensure that it is running.

kubectl get pods

To retrieve all currently available application logs from the running pod and store them in the file /opt/KDOB0020l/log_Output.txt, you can use the kubectl logs command. The logs command retrieves logs from a container in a pod.

kubectl logs -f < pod-name > > /opt/KDOB0020l/log_Output.txt

Replace < pod-name > with the name of the pod.

You can also use -f option to stream the logs.

kubectl logs -f < pod-name > > /opt/KDOB0020l/log_Output.txt &

This command will retrieve the logs from the pod and write them to the /opt/KDOB0020l/log_Output.txt file.

Please note that the above command will retrieve all logs from the pod, including previous logs. If you want to retrieve only the new logs that are generated after running the command, you can add the --since flag to the kubectl logs command and specify a duration, for example --since=24h for logs generated in the last 24 hours.

Also, please note that, if the pod has multiple containers, you need to specify the container name using -c option.

kubectl logs -f < pod-name > -c < container-name > > /opt/KDOB0020l/log_Output.txt

The above command will redirect the logs of the specified container to the file.

Solution:

Solution:

Solution:

Solution:

Do this on ckad00027 and edit the given manifest file (that’s what the task expects).

0) Connect to correct host

ssh ckad00027

1) Open the manifest and identify the container + port

cd /home/candidate/spicy-pikachu

ls -l

sed -n ' 1,200p ' app-deployment.yaml

Confirm the container port is 8081 in the YAML (usually under ports:).

2) Edit the YAML to add a readinessProbe

Edit the file:

vi app-deployment.yaml

Inside the Deployment, locate:

spec:

template:

spec:

containers:

- name: ...

image: ...

Add this under the container (same indentation level as image, ports, etc.):

readinessProbe:

httpGet:

path: /healthz

port: 8081

initialDelaySeconds: 6

periodSeconds: 3

Notes:

Use port: 8081 (because the app runs on 8081).

Ensure indentation is correct (2 spaces per level commonly).

Save and exit.

3) Apply the updated manifest

kubectl apply -f /home/candidate/spicy-pikachu/app-deployment.yaml

4) Ensure the Deployment rolls out successfully

kubectl -n prod rollout status deploy app-deployment

5) Verify the readiness probe is set

Check the probe from the live object:

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

And confirm pods are becoming Ready:

kubectl -n prod get pods -l app=app-deployment

If the label selector differs, just:

kubectl -n prod get pods

kubectl -n prod describe pod < pod-name > | sed -n ' /Readiness:/,/Conditions:/p '

That completes the task: readiness probe on /healthz , initialDelaySeconds: 6, periodSeconds: 3.

Solution:

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

Solution:

To update the nginxsvc service to serve on port 5050, you will need to edit the service ' s definition yaml file. You can use the kubectl edit command to edit the service in place.

kubectl edit svc nginxsvc

This will open the service definition yaml file in your default editor. Change the targetPort of the service to 5050 and save the file.

To add an HAproxy container named haproxy bound to port 90 to the poller pod, you will need to edit the pod ' s definition yaml file located at /opt/KDMC00101/poller.yaml.

You can add a new container to the pod ' s definition yaml file, with the following configuration:

containers:

- name: haproxy

image: haproxy

ports:

- containerPort: 90

volumeMounts:

- name: haproxy-config

mountPath: /usr/local/etc/haproxy/haproxy.cfg

subPath: haproxy.cfg

args: [ " haproxy " , " -f " , " /usr/local/etc/haproxy/haproxy.cfg " ]

This will add the HAproxy container to the pod and configure it to listen on port 90. It will also mount the ConfigMap haproxy-config to the container, so that haproxy.cfg is available at /usr/local/etc/haproxy/haproxy.cfg.

To inject the configuration located at /opt/KDMC00101/haproxy.cfg to the container, you will need to create a ConfigMap using the following command:

kubectl create configmap haproxy-config --from-file=/opt/KDMC00101/haproxy.cfg

You will also need to update the args of the poller container so that it connects to localhost instead of nginxsvc. You can do this by editing the pod ' s definition yaml file and changing the args field to args: [ " poller " , " --host=localhost " ] .

Once you have made these changes, you can deploy the updated pod to the cluster by running the following command:

kubectl apply -f /opt/KDMC00101/poller.yaml

This will deploy the enhanced pod with the HAproxy container to the cluster. The HAproxy container will listen on port 90 and proxy connections to the nginxsvc service on port 5050. The poller container will connect to localhost instead of nginxsvc, so that the connection is correctly proxied to the new service endpoint.

Please note that, this is a basic example and you may need to tweak the haproxy.cfg file and the args based on your use case.