CKAD Application Design and Build Practice Test 6 — 15 Questions

Question 1

A pod has two containers: a web server and a sidecar that scrapes logs. The sidecar container needs to read log files written by the web server. How should the logs be shared between the containers?

Accepted Answer

Use a shared emptyDir volume mounted into both containers at the same path. A shared volume, such as an emptyDir volume mounted into both containers, allows the sidecar to access the web server's log files.

Answer

Use a ConfigMap to store logs

Answer

Use a hostPath volume mounted in both containers

Answer

Use a PersistentVolumeClaim

Question 2

You need to run a one-time batch job that processes 10 work items in parallel, with a maximum of 3 pods running at the same time. Which Job YAML fields should you set?

Accepted Answer

spec.parallelism: 3 and spec.completions: 10. The .spec.parallelism field sets the maximum number of pods running concurrently, and .spec.completions sets the total number of successful completions required.

Answer

spec.template.spec.containers and spec.completions

Answer

spec.parallelism: 10 and spec.completions: 3

Answer

spec.backoffLimit: 3 and spec.completions: 10

Question 3

You have a CronJob that runs every 5 minutes. The job sometimes takes longer than 5 minutes to complete. You want to ensure that while a job is running, the next scheduled job is skipped (not started). Which concurrencyPolicy should you use?

Accepted Answer

Forbid. concurrencyPolicy: Forbid prevents new jobs from starting while the previous job is still running.

Answer

Skip

Answer

Allow

Answer

Replace

Question 4

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 run before the main containers in a pod and must complete successfully before the main containers start.

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 5

You want to create a Deployment that runs 5 replicas of a web application. Which kubectl command should you use?

Accepted Answer

kubectl create deployment webapp --image=nginx --replicas=5. The command 'kubectl create deployment' creates a Deployment with the specified number of replicas.

Answer

kubectl run webapp --image=nginx --replicas=5

Answer

kubectl create pod webapp --image=nginx --replicas=5

Answer

kubectl apply -f deployment.yaml

Question 6

You have a Job that should retry up to 3 times if it fails, and should be considered failed after 4 failures total (including retries). Which YAML fields should you set?

Accepted Answer

spec.backoffLimit: 3. The .spec.backoffLimit field sets the number of retries, and .spec.activeDeadlineSeconds sets a timeout for the job. However, the question asks for failures total. By default, the backoff limit is 6, but setting it to 3 means 4 total attempts (initial + 3 retries). The field that controls retries is backoffLimit, and activeDeadlineSeconds is optional. However, the most direct answer is to set backoffLimit: 4? Actually, the initial attempt is not a retry; backoffLimit defines the number of retries. So for 4 total attempts, set backoffLimit: 3. But the options need to be evaluated. Let's create plausible distractors.

Answer

spec.activeDeadlineSeconds: 4

Answer

spec.backoffLimit: 4

Answer

spec.restartPolicy: OnFailure and spec.backoffLimit: 3

Question 7

Which of the following is true about the CMD instruction in a Dockerfile?

Accepted Answer

CMD provides a default command that can be overridden at runtime. CMD sets the default command to run when the container starts, but it can be overridden by command-line arguments to docker run.

Answer

CMD is always executed during the image build process

Answer

CMD is used to expose ports

Answer

CMD cannot be used in conjunction with ENTRYPOINT

Question 8

You want to debug a running pod by starting a temporary container that has network access to the pod's containers. Which kubectl command should you use?

Accepted Answer

kubectl debug -it --image=debian --target=. The 'kubectl debug' command with the '-i' (interactive) and '--image' flags creates an ephemeral container for debugging.

Answer

kubectl attach <pod>

Answer

kubectl run debug --image=debian --restart=Never

Answer

kubectl exec -it <pod> -- /bin/bash

Question 9

Which Dockerfile instruction is used to define a mount point for a volume?

Accepted Answer

VOLUME. The VOLUME instruction creates a mount point for externally mounted volumes or other containers.

Answer

ADD

Answer

EXPOSE

Answer

MOUNT

Question 10

Which TWO of the following are valid patterns for sidecar containers in Kubernetes?

Accepted Answer

Ambassador. Sidecar, adapter, and ambassador are the three common sidecar patterns. The sidecar pattern adds functionality to the main container, the adapter pattern transforms interfaces, and the ambassador pattern proxies connections.

Answer

Singleton

Answer

DaemonSet

Question 11

Which THREE of the following are valid fields in a CronJob specification?

Accepted Answer

successfulJobsHistoryLimit. schedule, concurrencyPolicy, and successfulJobsHistoryLimit are fields in a CronJob spec. completions is a field in Job spec, not directly in CronJob.

Answer

completions

Answer

parallelism

Question 12

Which TWO of the following are true about .dockerignore files?

Accepted Answer

They are placed in the root of the build context. .dockerignore files exclude files from the build context, improving build performance and security by preventing unwanted files from being copied into the image.

Answer

They are optional and have no effect on the build

Answer

They can be used to ignore files only for specific build stages

Answer

They can include files that are in parent directories

Question 13

A pod in the 'production' namespace is in a CrashLoopBackOff state. The pod has been running successfully for several days. You run 'kubectl describe pod app-pod -n production' and see the message: 'OOMKilled'. What is the MOST appropriate action to resolve this issue?

Accepted Answer

Increase the memory limit in the pod's container resource specification. Option B is correct. OOMKilled means the container exceeded its memory limit and was killed by the kernel OOM killer. The solution is to increase the memory limit in the container's resource specification. Option A would not help — restarting the pod without addressing the root cause will result in the same failure. Option C addresses CPU, not memory. Option D (deleting the namespace) is destructive and unnecessary.

Answer

Increase the CPU request for the container

Answer

Delete the namespace and redeploy all workloads

Answer

Delete and recreate the pod to clear the crash loop

Question 14

Which of the following is the correct way to create a simple Pod named 'nginx' running the nginx:1.25 image using kubectl?

Accepted Answer

kubectl run nginx --image=nginx:1.25. Option C is correct. The 'kubectl run' command with the '--image' flag creates a pod. Option A is incorrect because 'kubectl create pod' is not a valid command; you would use 'kubectl create deployment' or 'kubectl run'. Option B is incorrect because 'kubectl apply' expects a YAML file, not an image argument directly. Option D is incorrect because 'kubectl create' expects a resource type (e.g., 'deployment'), not 'pod' directly.

Answer

kubectl create nginx --image=nginx:1.25

Answer

kubectl create pod nginx --image=nginx:1.25

Answer

kubectl apply nginx --image=nginx:1.25

Question 15

You have a Pod that runs a web server and you want to add a sidecar container that exposes a Prometheus metrics endpoint by scraping the web server's logs. Which sidecar pattern does this exemplify?

Accepted Answer

Adapter pattern. Option A is correct. The adapter pattern transforms the main container's output (e.g., logs) into a format expected by an external system (e.g., Prometheus metrics). The sidecar pattern adds functionality without modifying the main container; ambassador patterns proxy external connections; init containers run before the main containers start.

Answer

Sidecar pattern (generic)

Answer

Ambassador pattern

Answer

Init container pattern