CKA Certified Kubernetes Administrator (CKA) Program Questions and Answers

Task Overview

You're restoring a MariaDB deployment in the mariadb namespace with persistent data.

✅ Tasks:

SSH into cka000047

Create a PVC named mariadb:

Namespace: mariadb

Access mode: ReadWriteOnce

Storage: 250Mi

Use the existing retained PV (there’s only one)

Edit ~/mariadb-deployment.yaml to use the PVC

Apply the deployment

Verify MariaDB is running and stable

Step-by-Step Solution

1️⃣ SSH into the correct host

ssh cka000047

⚠️ Required — skipping = zero score

2️⃣ Inspect the existing PersistentVolume

kubectl get pv

✅ Identify the only existing PV, e.g.:

NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS

mariadb-pv 250Mi RWO Retain Available manual

Ensure the status is Available, and it is not already bound to a claim.

3️⃣ Create the PVC to bind the retained PV

Create a file mariadb-pvc.yaml:

cat < mariadb-pvc.yaml

apiVersion: v1

kind: PersistentVolumeClaim

metadata:

name: mariadb

namespace: mariadb

spec:

accessModes:

- ReadWriteOnce

resources:

requests:

storage: 250Mi

volumeName: mariadb-pv # Match the PV name exactly

EOF

Apply the PVC:

kubectl apply -f mariadb-pvc.yaml

✅ This binds the PVC to the retained PV.

4️⃣ Edit the MariaDB Deployment YAML

Open the file:

nano ~/mariadb-deployment.yaml

Look under the spec.template.spec.containers.volumeMounts and spec.template.spec.volumes sections and update them like so:

Add this under the container:

yaml

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volumeMounts:

- name: mariadb-storage

mountPath: /var/lib/mysql

And under the pod spec:

volumes:

- name: mariadb-storage

persistentVolumeClaim:

claimName: mariadb

✅ These lines mount the PVC at the MariaDB data directory.

5️⃣ Apply the updated Deployment

kubectl apply -f ~/mariadb-deployment.yaml

6️⃣ Verify the Deployment is running and stable

kubectl get pods -n mariadb

kubectl describe pod -n mariadb

✅ Ensure the pod is in Running state and volume is mounted.

???? Final Command Summary

ssh cka000047

kubectl get pv # Find the retained PV

# Create PVC

cat < mariadb-pvc.yaml

apiVersion: v1

kind: PersistentVolumeClaim

metadata:

name: mariadb

namespace: mariadb

spec:

accessModes:

- ReadWriteOnce

resources:

requests:

storage: 250Mi

volumeName: mariadb-pv

EOF

kubectl apply -f mariadb-pvc.yaml

# Edit Deployment

nano ~/mariadb-deployment.yaml

# Add volumeMount and volume to use the PVC as described

kubectl apply -f ~/mariadb-deployment.yaml

kubectl get pods -n mariadb

kubect1 get pods--sort-by=.metadata.creationTimestamp

solution

F:\Work\Data Entry Work\Data Entry\20200827\CKA\18 C.JPG

Kubectl logs frontend | grep -i “started” > /opt/error-logs

kubectl get po -o=custom-columns="POD_NAME:.metadata.name,

POD_STATUS:.status.containerStatuses[].state"

Solution:

solution

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F:\Work\Data Entry Work\Data Entry\20200827\CKA\21 E.JPG

F:\Work\Data Entry Work\Data Entry\20200827\CKA\21 F.JPG

F:\Work\Data Entry Work\Data Entry\20200827\CKA\21 G.JPG

Solution:

kubectl top -l name=cpu-user -A

echo 'pod name' >> /opt/KUT00401/KUT00401.txt

solution

You must use the kubeadm configuration file located at /etc/kubeadm.conf when initializing

your cluster.

You may use any CNI plugin to complete this task, but if you don't have your favourite CNI plugin's manifest URL at hand, Calico is one popular option: https://docs.projectcalico.org/v3.14/manifests/calico.yaml

Docker is already installed on both nodes and apt has been configured so that you can install the required tools.

Task Summary

SSH into the correct node: cka000037

Modify existing deployment synergy-leverager

Add a sidecar container:

Name: sidecar

Image: busybox:stable

Command:

/bin/sh -c "tail -n+1 -f /var/log/synergy-leverager.log"

Use a shared volume mounted at /var/log

Don't touch existing container config except adding volume mount

Step-by-Step Solution

1️⃣ SSH into the correct node

ssh cka000037

⚠️ Skipping this will result in a zero score.

2️⃣ Edit the deployment

kubectl edit deployment synergy-leverager

This opens the deployment YAML in your default editor (vi or similar).

3️⃣ Modify the spec as follows

???? Inside the spec.template.spec, do these 3 things:

✅ A. Define a shared volume

Add under volumes: (at the same level as containers):

volumes:

- name: log-volume

emptyDir: {}

✅ B. Add volume mount to the existing container

Locate the existing container under containers: and add this:

volumeMounts:

- name: log-volume

mountPath: /var/log

???? Do not change any other configuration for this container.

✅ C. Add the sidecar container

Still inside containers:, add the new container definition after the first one:

- name: sidecar

image: busybox:stable

command:

- /bin/sh

- -c

- "tail -n+1 -f /var/log/synergy-leverager.log"

volumeMounts:

- name: log-volume

mountPath: /var/log

spec:

containers:

- name: main-container

image: your-existing-image

volumeMounts:

- name: log-volume

mountPath: /var/log

- name: sidecar

image: busybox:stable

command:

- /bin/sh

- -c

- "tail -n+1 -f /var/log/synergy-leverager.log"

volumeMounts:

- name: log-volume

mountPath: /var/log

volumes:

- name: log-volume

emptyDir: {}

Save and exit

If using vi or vim, type:

bash

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wq

5️⃣ Verify

Check the updated pods:

kubectl get pods -l app=synergy-leverager

Pick a pod name and describe it:

kubectl describe pod

Confirm:

2 containers running (main-container + sidecar)

Volume mounted at /var/log

ssh cka000037

kubectl edit deployment synergy-leverager

# Modify as explained above

kubectl get pods -l app=synergy-leverager

kubectl describe pod

image=nginx, image=redis, image=consul

Name nginx container as “nginx-container”

Name redis container as “redis-container”

Name consul container as “consul-container”

Create a pod manifest file for a container and append container

section for rest of the images

kubectl run multi-container --generator=run-pod/v1 --image=nginx --

dry-run -o yaml > multi-container.yaml

# then

vim multi-container.yaml

apiVersion: v1

kind: Pod

metadata:

labels:

run: multi-container

name: multi-container

spec:

containers:

- image: nginx

name: nginx-container

- image: redis

name: redis-container

- image: consul

name: consul-container

restartPolicy: Always

kubectl run nginx --image=nginx --restart=Never --env=var1=value1

# then

kubectl exec -it nginx -- env

# or

kubectl exec -it nginx -- sh -c 'echo $var1'

# or

kubectl describe po nginx | grep value1

solution

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Solution:

kubectl get deploy front-end

kubectl edit deploy front-end -o yaml

#port specification named http

#service.yaml

apiVersion: v1

kind: Service

metadata:

name: front-end-svc

labels:

app: nginx

spec:

ports:

- port: 80

protocol: tcp

name: http

selector:

app: nginx

type: NodePort

# kubectl create -f service.yaml

# kubectl get svc

# port specification named http

kubectl expose deployment front-end --name=front-end-svc --port=80 --tarport=80 --type=NodePort

kubect1 get pods -o=jsonpath='{range

items[*]}{.metadata.name}{"\t"}{.status.podIP}{"\n"}{end}'

Solution:

sudo -i

systemctl status kubelet

systemctl start kubelet

systemctl enable kubelet

solution

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F:\Work\Data Entry Work\Data Entry\20200827\CKA\7 C.JPG

F:\Work\Data Entry Work\Data Entry\20200827\CKA\7 D.JPG

Solution:

kubectl logs bar | grep 'unable-to-access-website' > /opt/KUTR00101/bar

cat /opt/KUTR00101/bar

Solution:

kubectl get deployment

kubectl scale deployment.apps/presentation --replicas=6

Task Summary

You are given a host to prepare for Kubernetes:

Use dpkg to install cri-dockerd

Enable and start the cri-docker service

Set net.bridge.bridge-nf-call-iptables to 1 via sysctl

Step-by-Step Instructions

1️⃣ SSH into the correct node

bash

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ssh cka000051

⚠️ Required — failure to connect to the correct host = zero score.

2️⃣ Install cri-dockerd

You are told the .deb file is already located at:

bash

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~/cri-dockerd_0.3.9.3-0.ubuntu-jammy_amd64.deb

Install it with dpkg:

bash

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sudo dpkg -i ~/cri-dockerd_0.3.9.3-0.ubuntu-jammy_amd64.deb

???? If any dependencies are missing (e.g., golang or containerd), you might need:

bash

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sudo apt-get install -f -y

But usually, the exam system provides a pre-validated .deb environment.

3️⃣ Enable and start cri-docker service

Start and enable both services:

bash

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sudo systemctl enable cri-docker.service

sudo systemctl enable --now cri-docker.socket

sudo systemctl start cri-docker.service

Check status (optional but smart):

bash

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sudo systemctl status cri-docker.service

You should see it active (running).

4️⃣ Configure the sysctl parameter

Set net.bridge.bridge-nf-call-iptables=1 immediately and persistently.

Step A: Apply immediately:

sudo sysctl net.bridge.bridge-nf-call-iptables=1

Step B: Persist it in /etc/sysctl.d:

Create or modify a file:

echo "net.bridge.bridge-nf-call-iptables = 1" | sudo tee /etc/sysctl.d/k8s.conf

Reload sysctl:

sudo sysctl --system

Verify:

sysctl net.bridge.bridge-nf-call-iptables

Should return:

net.bridge.bridge-nf-call-iptables = 1

✅ Now the system is ready for kubeadm with Docker (via cri-dockerd)!

ssh cka000051

sudo dpkg -i ~/cri-dockerd_0.3.9.3-0.ubuntu-jammy_amd64.deb

sudo systemctl enable cri-docker.service

sudo systemctl enable --now cri-docker.socket

sudo systemctl start cri-docker.service

sudo sysctl net.bridge.bridge-nf-call-iptables=1

echo "net.bridge.bridge-nf-call-iptables = 1" | sudo tee /etc/sysctl.d/k8s.conf

sudo sysctl --system

kubectl run busybox --image=busybox -it --rm --restart=Never --

/bin/sh -c 'echo hello world'

kubectl get po # You shouldn't see pod with the name "busybox"