CKAD Application Design and Build Practice Test 4 — 15 Questions

Question 1

A CronJob is configured with concurrencyPolicy: Replace and a job execution takes 10 minutes. The schedule is */5 * * * *. Which statement is true about job executions?

Accepted Answer

Every 5 minutes, a new job is created, and if the previous job is still running, it is killed. With `concurrencyPolicy: Replace`, if a new job is triggered by the schedule (every 5 minutes) while the previous job is still running (it takes 10 minutes), the running job is terminated and replaced by the new one. This ensures only one job runs at a time, and the new job starts immediately, even if the previous one hasn't finished.

Answer

Jobs will never overlap because the schedule is too frequent

Answer

The job will be skipped if the previous one hasn't finished

Answer

Jobs will overlap, with up to two jobs running concurrently

Question 2

A DevOps engineer wants to deploy a logging sidecar container that reads log files from the main application container. Which volume type should be used to share files between the two containers?

Accepted Answer

emptyDir. An emptyDir volume is the correct choice because it provides a shared, ephemeral storage space that is created when a Pod is assigned to a node and exists as long as that Pod is running. Both the main application container and the sidecar container can mount the same emptyDir volume at different mount paths, allowing the sidecar to read log files written by the main container. This volume type is ideal for sharing files between containers in the same Pod without requiring persistent storage.

Answer

persistentVolumeClaim

Answer

configMap

Answer

hostPath

Question 3

A Pod has two containers: one with a liveness probe that fails after 30 seconds. The restartPolicy is 'Never'. What state will the Pod be in after the liveness probe fails?

Accepted Answer

Failed. When a liveness probe fails, Kubernetes terminates the container and, because the restartPolicy is 'Never', does not restart it. The Pod transitions to the 'Failed' phase, as the container has exited with a non-zero exit code and will not be recreated. This is the expected behavior for a Pod with a single container that fails its health check under a 'Never' restart policy.

Answer

Running

Answer

Unknown

Answer

CrashLoopBackOff

Question 4

Which command builds a Docker image from the current directory and tags it as 'myapp:v1'?

Accepted Answer

docker build -t myapp:v1 .. The `docker build` command with the `-t` flag (short for `--tag`) is the standard way to build an image from a Dockerfile in the current directory (`.`) and assign it a tag `myapp:v1`. The `-t` flag specifies the repository and tag in the format `name:tag`, and the `.` indicates the build context (the current directory).

Answer

docker image build --name myapp:v1 .

Answer

docker build myapp:v1 .

Answer

docker tag myapp:v1 .

Question 5

A developer wants to create a Job that runs exactly 3 pods in parallel. Which field should be set in the Job spec?

Accepted Answer

spec.parallelism: 3. `spec.parallelism` in a Kubernetes Job spec defines the desired number of Pods that should run concurrently. Setting `spec.parallelism: 3` tells the Job controller to run exactly 3 Pods in parallel, meeting the requirement of running 3 pods simultaneously.

Answer

spec.ttlSecondsAfterFinished: 3

Answer

spec.backoffLimit: 3

Answer

spec.completions: 3

Question 6

In a Dockerfile, what is the difference between CMD and ENTRYPOINT?

Accepted Answer

ENTRYPOINT defines the executable and CMD provides default arguments. C is correct because in a Dockerfile, ENTRYPOINT specifies the executable that will always run when the container starts, while CMD provides default arguments that can be overridden. When both are defined, CMD arguments are appended to the ENTRYPOINT command, allowing flexible default behavior that users can modify at runtime via the command line.

Answer

CMD always runs, ENTRYPOINT can be overridden

Answer

There is no difference; they are interchangeable

Answer

CMD is used for shell form, ENTRYPOINT for exec form

Question 7

A user runs: kubectl apply -f job.yaml. The Job spec has backoffLimit: 0. The pod fails immediately. What happens?

Accepted Answer

The Job enters a Failed state. When `backoffLimit: 0` is set in a Job spec and the pod fails immediately, the Job controller does not retry the pod because the backoff limit is zero. According to Kubernetes Job semantics, the Job is considered failed once the number of failures reaches the `backoffLimit` (0 in this case), so the Job transitions to a Failed state without any further pod creation or retries.

Answer

The Job is retried indefinitely

Answer

The pod is restarted until it succeeds

Answer

A new pod is created automatically

Question 8

An administrator creates a Pod with an ephemeral container using 'kubectl debug my-pod -it --image=busybox --target=my-container'. The ephemeral container shares the same process namespace as the target container. Which flag enables this?

Accepted Answer

--target. The `--target` flag in `kubectl debug` specifies the target container within the Pod for the ephemeral container. When used, the ephemeral container shares the same process namespace as the target container, allowing tools like `ps` to see processes from the target container. This is essential for debugging scenarios where you need to inspect or interact with the target container's processes.

Answer

--container

Answer

--namespace

Answer

--share-process-namespace

Question 9

Which Kubernetes API version is used for creating a CronJob?

Accepted Answer

batch/v1. CronJob is a Kubernetes resource that was promoted to a stable API version in Kubernetes 1.21. The correct API version for creating a CronJob is batch/v1, as it is the current stable version. The batch/v1beta1 version is deprecated and removed in Kubernetes 1.25, so batch/v1 is the correct choice for CKAD exam scenarios.

Answer

batch/v1beta1

Answer

cron/v1

Answer

apps/v1

Question 10

Which TWO statements about Init Containers are correct? (Select exactly 2.)

Accepted Answer

Init containers run to completion sequentially before any app containers start. Option B is correct because Kubernetes executes init containers one at a time, in the order defined in the pod spec, and each must run to completion successfully before the next init container or any app container starts. Option C is correct because each init container is defined with its own image field in the pod spec, so it can use a completely different container image (and different tooling) than the app containers. Option A is wrong because init containers run sequentially, not in parallel, which is the opposite of what the statement claims. Option D is wrong because if an init container fails, Kubernetes restarts it according to the pod's restartPolicy (Always, OnFailure, or Never), not unconditionally regardless of restartPolicy. Option E is wrong because init containers do not support liveness, readiness, or startup probes; they are only expected to run to completion.

Answer

Init containers run in parallel to reduce startup time

Answer

If an init container fails, Kubernetes restarts it until it succeeds regardless of restartPolicy

Answer

Init containers can have liveness and readiness probes

Question 11

A team wants to deploy a multi-container Pod with a sidecar pattern. Which THREE statements are true about sidecar containers? (Select exactly 3.)

Accepted Answer

Sidecar containers are used for tasks like log collection, service mesh proxies, or data synchronization. Sidecar containers are auxiliary containers that enhance or extend the functionality of the main application container. Common use cases include log collection (e.g., Fluentd), service mesh proxies (e.g., Envoy), and data synchronization (e.g., rsync or a Git sync sidecar). These tasks support the primary workload without altering its code.

Answer

Sidecar containers are always started before the main container

Answer

Sidecar containers can be updated independently without restarting the main container

Question 12

Which Dockerfile instruction is used to specify the base image for a container image?

Accepted Answer

FROM. The FROM instruction initializes a new build stage and sets the base image for subsequent instructions. It must be the first non-comment instruction in a Dockerfile, pulling a specified image from a registry (e.g., Docker Hub) to provide the filesystem and runtime environment for the container.

Answer

COPY

Answer

CMD

Answer

RUN

Question 13

A developer is writing a Dockerfile and wants to ensure that the container runs a Python script named 'app.py' as its main process. Which instruction should be used?

Accepted Answer

ENTRYPOINT ["python", "app.py"]. ENTRYPOINT defines the executable that runs as the main process in the container. When combined with CMD (or used alone in exec form), it ensures that 'python app.py' is the primary process with PID 1, which is essential for proper signal handling and container lifecycle management.

Answer

EXPOSE 8080

Answer

CMD ["python", "app.py"]

Answer

RUN ["python", "app.py"]

Question 14

You have a multi-stage Docker build. The first stage compiles a binary, and the second stage copies the binary from the first stage. What is the correct COPY syntax to copy a file named 'app' from the first stage named 'builder'?

Accepted Answer

COPY --from=builder app /app/. The `--from=builder` flag in the COPY instruction allows you to copy files from a specific build stage (named 'builder') in a multi-stage Docker build. This syntax is essential for multi-stage builds, where the first stage compiles artifacts and the second stage copies only the necessary binaries, reducing final image size.

Answer

COPY app /app/

Answer

COPY --stage=builder app /app/

Answer

COPY source=builder app /app/

Question 15

What is the purpose of the '.dockerignore' file?

Accepted Answer

To exclude files from the build context. The `.dockerignore` file is used to exclude files and directories from the build context sent to the Docker daemon during a `docker build` operation. By specifying patterns in this file, you prevent unnecessary or sensitive files (like local development artifacts, `.git` directories, or node_modules) from being included, which speeds up the build and reduces the image size. Option C correctly identifies this purpose.

Answer

To specify which files to include in the image

Answer

To ignore files during docker push

Answer

To list environment variables to ignore