CKAD Practice Test 12 — 15 Questions

Question 1

Which of the following best describes the purpose of an init container?

Accepted Answer

Init containers run to completion before the main containers start, and are used for setup tasks. Init containers are specialized containers that run and complete to exit before any pod's main containers start. They are ideal for performing setup tasks such as waiting for a service to be ready, populating configuration files, or running database migrations. This ensures the main application containers start in a fully prepared environment.

Answer

Init containers run in parallel with the main containers to provide auxiliary functionality

Answer

Init containers share the same lifecycle as the main containers

Answer

Init containers are restarted if they exit with a non-zero exit code

Question 2

Which command creates a generic secret named 'db-secret' with key 'password' and value 'p@ss'?

Accepted Answer

kubectl create secret generic db-secret --from-literal=password=p@ss. `kubectl create secret generic` with `--from-literal` allows you to specify key-value pairs directly on the command line. The syntax `--from-literal=password=p@ss` creates a generic secret with the key 'password' and the literal value 'p@ss', which matches the requirement exactly.

Answer

kubectl create secret generic db-secret --from-file=password=p@ss

Answer

kubectl create secret tls db-secret --from-literal=password=p@ss

Answer

kubectl create secret docker-registry db-secret --from-literal=password=p@ss

Question 3

You have a Dockerfile with a multi-stage build. The first stage is named 'builder' and uses 'golang:1.20' to compile a binary. The second stage uses 'alpine:3.18' and should copy the binary from the first stage. Which COPY instruction is correct?

Accepted Answer

COPY --from=builder /app/myapp /usr/local/bin/myapp. In a multi-stage Docker build, the `COPY --from=<name|index>` instruction copies files from a named previous stage. Option D correctly uses the stage name 'builder' to copy the compiled binary from the first stage into the final Alpine image. This is the standard and most readable approach for multi-stage builds.

Answer

ADD --from=builder /app/myapp /usr/local/bin/myapp

Answer

COPY /app/myapp /usr/local/bin/myapp

Answer

COPY --from=0 /app/myapp /usr/local/bin/myapp

Question 4

Which two statements about ConfigMaps and Secrets are correct? (Select TWO.)

Accepted Answer

Secrets store data in base64-encoded form, while ConfigMaps store plaintext. Secrets store data as base64-encoded strings, which is not encryption but a simple encoding that obscures the data. ConfigMaps store data in plaintext (UTF-8) without any encoding. This distinction is fundamental: base64 encoding is reversible and provides no security, while plaintext is human-readable.

Answer

ConfigMaps are immutable and cannot be updated after creation

Answer

ConfigMaps are suitable for storing sensitive data like passwords

Answer

Secrets are encrypted at rest by default in Kubernetes

Question 5

A pod is stuck in 'Pending' state. You run 'kubectl describe pod my-pod' and see the event: '0/3 nodes are available: 3 Insufficient cpu.' Which action should you take?

Accepted Answer

Reduce the CPU request of the pod and reapply the manifest.. The pod is stuck in 'Pending' because the scheduler cannot find a node with enough allocatable CPU to satisfy the pod's CPU request. Reducing the CPU request (the amount guaranteed to the container) makes the pod schedulable on existing nodes. Increasing limits would only worsen the problem, as limits are a cap on usage, not a scheduling constraint.

Answer

Increase the CPU limits on the pod to give it more resources.

Answer

Add another node to the cluster to increase overall CPU capacity.

Answer

Add a nodeSelector to the pod to target a specific node.

Question 6

You need to mount a Secret 'db-secret' as a volume in a pod, making its keys appear as individual files. Which volume definition is correct?

Accepted Answer

volumes: - name: secret-vol secret: secretName: db-secret. It defines a volume of type `secret` with the `secretName` field set to `db-secret`, which mounts the entire Secret as a volume. By default, each key in the Secret becomes a file named after the key, satisfying the requirement that keys appear as individual files.

Answer

volumes: - name: secret-vol emptyDir: medium: Secret

Answer

volumes: - name: secret-vol secret: secretName: db-secret items: - key: password path: credentials.txt

Answer

volumes: - name: secret-vol configMap: name: db-secret

Question 7

Which kubectl command creates a ConfigMap named 'app-config' from a file 'app.properties'?

Accepted Answer

kubectl create configmap app-config --from-file=app.properties. `kubectl create configmap app-config --from-file=app.properties` reads the file `app.properties` and creates a ConfigMap with a single key-value pair where the key is the filename (without extension) and the value is the entire file content. This is the standard way to create a ConfigMap from a file in Kubernetes.

Answer

kubectl create configmap app-config --from-literal=app.properties

Answer

kubectl create configmap app-config --from-env-file=app.properties

Answer

kubectl create configmap app-config --file=app.properties

Question 8

Which command correctly creates a Role named 'pod-reader' that allows get, list, and watch on pods?

Accepted Answer

kubectl create role pod-reader --verb=get,list,watch --resource=pods. The `kubectl create role` command uses the `--verb` flag (singular) with comma-separated values and the `--resource` flag (singular) with the lowercase plural resource name 'pods'. This matches the Kubernetes API convention where resources are specified as lowercase plurals (e.g., 'pods', 'deployments') and verbs are comma-separated.

Answer

kubectl create role pod-reader --verb=get --verb=list --verb=watch --resource=pods

Answer

kubectl create role pod-reader --verb=get,list,watch --resource=Pod

Answer

kubectl create role pod-reader --verbs=get,list,watch --resources=pods

Question 9

You want to perform a canary deployment. You have a Deployment 'app-v1' with 10 replicas. You create a new Deployment 'app-v2' with 1 replica. Both have the label 'app: myapp'. The Service 'myapp-svc' uses selector 'app: myapp'. How do you gradually increase traffic to v2?

Accepted Answer

Gradually increase the replicas of app-v2 and decrease those of app-v1.. By increasing the number of replicas in the v2 Deployment, more pods will be available to receive traffic from the Service, as both versions share the same label.

Answer

Create a second Service for v2 and use DNS weighting.

Answer

Update the Service selector to include version labels.

Answer

Use 'kubectl set image' on the existing Deployment.

Question 10

You are implementing a blue-green deployment using Kubernetes Deployments and Services. The 'blue' Deployment runs version 1.0, and the 'green' Deployment runs version 2.0. What is the key mechanism to switch traffic from blue to green?

Accepted Answer

Update the Service's label selector to match the green Deployment's pod labels. By updating the Service's label selector to match the green Deployment's pod labels, the Service routes traffic to the new version.

Answer

Scale down the blue Deployment to 0 replicas

Answer

Delete the blue Deployment

Answer

Change the Service type from ClusterIP to NodePort

Question 11

Which kubectl command sets the number of replicas for a deployment named 'nginx' to 5?

Accepted Answer

kubectl scale deployment nginx --replicas=5. kubectl scale is the correct command to change the replica count of a deployment.

Answer

kubectl update deployment nginx --replicas=5

Answer

kubectl set scale deployment nginx --replicas=5

Answer

kubectl resize deployment nginx --replicas=5

Question 12

During a rolling update of a Deployment with 10 replicas, you set maxSurge to 3 and maxUnavailable to 2. What is the maximum number of pods that can be unavailable during the update?

Accepted Answer

2. maxUnavailable: 2 means at most 2 pods can be unavailable. Option C is correct.

Answer

5

Answer

3

Answer

10

Question 13

During a rolling update of a Deployment, you notice that new pods are failing readiness probes. The rollout is stalled. Which command would you use to abort the rollout and revert to the previous revision?

Accepted Answer

kubectl rollout undo deployment . 'kubectl rollout undo deployment ' reverts the rollout to the previous revision. Option A is correct.

Answer

kubectl rollout pause deployment <name>

Answer

kubectl rollout resume deployment <name>

Answer

kubectl delete deployment <name> --cascade=false

Question 14

A HorizontalPodAutoscaler (HPA) is configured to scale a Deployment based on CPU utilization. The target CPU utilization percentage is set to 80%. The current CPU utilization is 90%. What will the HPA do?

Accepted Answer

Scale up the number of replicas. The HPA will increase the number of replicas to bring CPU utilization down towards 80%. The exact new replicas depends on the metric, but generally it scales up.

Answer

Delete the pod with the highest CPU usage

Answer

Do nothing because 90% is within acceptable range

Answer

Scale down the number of replicas

Question 15

Which kubectl command is used to view the rollout status of a Deployment?

Accepted Answer

kubectl rollout status deployment mydeployment. The 'kubectl rollout status' command is specifically designed to show the status of a rollout for a Deployment, DaemonSet, or StatefulSet.

Answer

kubectl status deployment mydeployment

Answer

kubectl get rollout deployment mydeployment

Answer

kubectl describe rollout mydeployment