CKAD Certified Kubernetes Application Developer (CKAD) Program Questions and Answers

Solution:

ssh ckad00023

You need two outcomes in moose:

At most 10 Pods total (across both Deployments).

About 20% of chipmunk-service traffic goes to canary-chipmunk-deployment.

In Kubernetes Services, traffic distribution is (roughly) proportional to the number of ready endpoints behind the Service. So the standard canary trick is:

total endpoints = 10

canary endpoints = 2

current endpoints = 8That gives ~20% to canary.

1) Inspect what exists

kubectl -n moose get deploy

kubectl -n moose get svc chipmunk-service -o wide

kubectl -n moose describe svc chipmunk-service

Get the Service selector (important):

kubectl -n moose get svc chipmunk-service -o jsonpath='{.spec.selector}{"\n"}'

Check current replicas:

kubectl -n moose get deploy current-chipmunk-deployment -o jsonpath='{.spec.replicas}{"\n"}'

kubectl -n moose get deploy canary-chipmunk-deployment -o jsonpath='{.spec.replicas}{"\n"}'

List pods + labels (to confirm both Deployments’ pods match the Service selector):

kubectl -n moose get pods --show-labels

2) Ensure both Deployments are behind the Service

This is the key: the pods from BOTH deployments must match the Service selector.

If the Service selector is something like app=chipmunk, then both Deployments’ pod templates must include app: chipmunk.

If one Deployment doesn’t match, patch its pod template labels to match the selector.

2A) Example: selector is app=chipmunk

(Only do this if you see the Service selector contains app=chipmunk and one of the deployments is missing it.)

kubectl -n moose patch deploy current-chipmunk-deployment \

-p '{"spec":{"template":{"metadata":{"labels":{"app":"chipmunk"}}}}}'

kubectl -n moose patch deploy canary-chipmunk-deployment \

-p '{"spec":{"template":{"metadata":{"labels":{"app":"chipmunk"}}}}}'

Wait for rollouts if patches triggered new ReplicaSets:

kubectl -n moose rollout status deploy current-chipmunk-deployment

kubectl -n moose rollout status deploy canary-chipmunk-deployment

Verify endpoints now include pods from both deployments:

kubectl -n moose get endpoints chipmunk-service -o wide

3) Set replicas to enforce “max 10 pods” and “20% canary”

Set:

current = 8

canary = 2Total = 10.

kubectl -n moose scale deploy current-chipmunk-deployment --replicas=8

kubectl -n moose scale deploy canary-chipmunk-deployment --replicas=2

Wait until ready:

kubectl -n moose rollout status deploy current-chipmunk-deployment

kubectl -n moose rollout status deploy canary-chipmunk-deployment

Confirm total pods is 10 (or less) and all are Running/Ready:

kubectl -n moose get pods

kubectl -n moose get pods | tail -n +2 | wc -l

Confirm endpoints count matches 10:

kubectl -n moose get endpoints chipmunk-service -o jsonpath='{.subsets[*].addresses[*].ip}' | wc -w

4) Test load balancing via NodePort 30000

Run several times:

for i in $(seq 1 30); do curl -s http://localhost:30000/; echo; done

You should see canary responses appear roughly ~20% of the time (not exact every run).

If you want a clearer signal, check which pods are endpoints and ensure 2 belong to canary and 8 to current:

kubectl -n moose get pods -l app=chipmunk -o wide

kubectl -n moose get endpoints chipmunk-service -o wide

Solution:

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 > /opt/KDOB0020l/log_Output.txt

Replace with the name of the pod.

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

kubectl logs -f > /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 -c > /opt/KDOB0020l/log_Output.txt

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

ssh ckad00026

Your job is to edit /home/candidate/credible-mite/web.yaml so it uses APIs supported on Kubernetes 1.29+, then deploy it into namespace garfish.

Because I can’t see your file from here, the most reliable exam approach is:

run a server-side dry-run to reveal the exact deprecated/removed APIs and schema errors

edit the manifest to the modern API versions/fields

re-run dry-run until it passes

apply for real and verify rollout

1) Go to the manifest and run a server-side dry-run

cd /home/candidate/credible-mite

ls -l

sed -n '1,200p' web.yaml

Make sure the namespace exists:

kubectl get ns garfish || kubectl create ns garfish

Now run a server-side dry-run (this catches removed APIs on the cluster):

kubectl apply -n garfish -f web.yaml --dry-run=server

Whatever errors you get here tell you exactly what to fix.

2) Fix the common v1.15 → v1.29 API deprecations

Edit the file:

vi web.yaml

Below are the most common objects from older manifests and how to update them for 1.29+.

A) Deployments / DaemonSets / StatefulSets

Old (v1.15 often used):

extensions/v1beta1 or apps/v1beta1 or apps/v1beta2

New:

apiVersion: apps/v1

Also in apps/v1, .spec.selector is required and must match the pod template labels.

Example conversion:

apiVersion: apps/v1

kind: Deployment

metadata:

name: web

spec:

replicas: 2

selector:

matchLabels:

app: web

template:

metadata:

labels:

app: web

spec:

containers:

- name: web

image: nginx

Key rule:

spec.selector.matchLabels must exactly match spec.template.metadata.labels (at least for the keys you select on).

B) Ingress

Old:

apiVersion: extensions/v1beta1 (or networking.k8s.io/v1beta1)

New:

apiVersion: networking.k8s.io/v1

Required changes:

spec.rules.http.paths[].pathType is required (usually Prefix)

backend format changes from serviceName/servicePort to service.name/service.port.number (or .name for named ports)

Old backend:

backend:

serviceName: web

servicePort: 80

New backend:

backend:

service:

name: web

port:

number: 80

Full path example:

apiVersion: networking.k8s.io/v1

kind: Ingress

metadata:

name: web

spec:

rules:

- host: example.local

http:

paths:

- path: /

pathType: Prefix

backend:

service:

name: web

port:

number: 80

C) CronJob

Old:

apiVersion: batch/v1beta1

New:

apiVersion: batch/v1

Most fields stay the same; just update apiVersion.

D) PodDisruptionBudget

Old:

policy/v1beta1

New:

policy/v1

spec.selector/minAvailable/maxUnavailable remain, but apiVersion changes.

E) RBAC

Usually already:

rbac.authorization.k8s.io/v1 (this is fine)

F) Removed APIs you must delete/replace

If you see these in a v1.15-era manifest, they are removed in modern clusters:

PodSecurityPolicy (policy/v1beta1) is removed. You cannot deploy it on 1.29+. Remove it from the manifest (or replace with whatever your environment uses, but for CKAD tasks you usually delete PSP sections from the file).

Some old admission/alpha resources also removed.

If dry-run complains “no matches for kind … in version …”, that’s your cue.

3) Re-run dry-run until it succeeds

After you edit:

kubectl apply -n garfish -f web.yaml --dry-run=server

Keep iterating until there are no errors.

4) Deploy for real

kubectl apply -n garfish -f /home/candidate/credible-mite/web.yaml

5) Verify everything in namespace garfish

List what was created:

kubectl -n garfish get all

kubectl -n garfish get ingress 2>/dev/null || true

If there is a Deployment, verify rollout:

kubectl -n garfish get deploy

kubectl -n garfish rollout status deploy --all

Check pods/events if something fails:

kubectl -n garfish get pods -o wide

kubectl -n garfish describe pod

kubectl -n garfish get events --sort-by=.lastTimestamp | tail -n 30

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:

Solution:

ssh ckad00029

You must modify the existing Deployment store-deployment in namespace grubworm so that its containers:

run as user ID 10000

have Linux capability NET_BIND_SERVICE added

And you’re told to use the manifest file at:

/home/candidate/daring-moccasin/store-deplovment.vaml (note: the filename looks misspelled; follow it exactly on the host)

1) Inspect the current Deployment and locate the manifest file

kubectl -n grubworm get deploy store-deployment

ls -l /home/candidate/daring-moccasin/

Open the manifest:

sed -n '1,200p' "/home/candidate/daring-moccasin/store-deplovment.vaml"

2) Edit the manifest to add SecurityContext

Edit the file:

vi "/home/candidate/daring-moccasin/store-deplovment.vaml"

2.1 Set Pod-level runAsUser = 10000

Under:

spec.template.spec add:

securityContext:

runAsUser: 10000

2.2 Add NET_BIND_SERVICE capability at container-level

Under the container spec (for each container in containers:), add:

securityContext:

capabilities:

add: ["NET_BIND_SERVICE"]

A complete example of what it should look like (mind indentation):

apiVersion: apps/v1

kind: Deployment

metadata:

name: store-deployment

namespace: grubworm

spec:

template:

spec:

securityContext:

runAsUser: 10000

containers:

- name: store

image: someimage

securityContext:

capabilities:

add: ["NET_BIND_SERVICE"]

Important notes:

runAsUser can be set at Pod level (applies to all containers) or per-container. Pod-level is cleanest if all containers should run as 10000.

Capabilities must be set per-container (that’s where Kubernetes supports it).

Save and exit.

3) Apply the updated manifest

kubectl apply -f "/home/candidate/daring-moccasin/store-deplovment.vaml"

4) Ensure the Deployment rolls out

kubectl -n grubworm rollout status deploy store-deployment

5) Verify the settings are in effect

Check the rendered pod template:

kubectl -n grubworm get deploy store-deployment -o jsonpath='{.spec.template.spec.securityContext}{"\n"}'

kubectl -n grubworm get deploy store-deployment -o jsonpath='{.spec.template.spec.containers[0].securityContext}{"\n"}'

Verify on a running pod:

kubectl -n grubworm get pods

kubectl -n grubworm describe pod | sed -n '/Security Context:/,/Containers:/p'

kubectl -n grubworm describe pod | sed -n '/Containers:/,/Conditions:/p'

If there are multiple containers

Repeat the container-level securityContext.capabilities.add block for each container under spec.template.spec.containers.

Solution: