CKAD Application Observability and Maintenance Practice Test 2 — 15 Questions

Question 1

You are tasked with debugging a pod that is crashing so quickly that you cannot exec into it. Which approach should you use to gain access to the pod's filesystem?

Accepted Answer

kubectl debug -it --copy-to=-debug --image=busybox. Both options B and D are correct approaches to access the filesystem of a crashing pod. Option B uses `kubectl debug` with `--copy-to` to create a copy of the pod with a debugging container that shares the original pod's filesystem. Option D uses `kubectl debug` without `--copy-to` to add an ephemeral container to the existing pod, which also shares the pod's filesystem and allows shell access even if the original container is crashing. Option A is incorrect because it creates a new standalone pod without access to the target pod's filesystem. Option C is incorrect because `kubectl exec` requires the target container to be running, which it is not in a crashing state.

Answer

kubectl run debug --image=busybox -it --rm

Answer

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

Answer

kubectl debug -it <pod> --image=busybox

Question 2

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. The pod is in CrashLoopBackOff with an OOMKilled message, which indicates the container is being terminated by the Linux kernel's Out-Of-Memory (OOM) killer because it has exceeded its memory limit. Increasing the memory limit in the pod's container resource specification allows the container to use more memory without being killed, directly addressing the root cause.

Answer

Increase the CPU request for the container

Answer

Delete and recreate the pod to clear the crash loop

Answer

Delete the namespace and redeploy all workloads

Question 3

You need to view the logs of a container named 'sidecar' in a pod called 'app-pod' running in namespace 'dev'. Which command should you use?

Accepted Answer

kubectl logs app-pod --container=sidecar --namespace=dev. Both `kubectl logs app-pod -c sidecar -n dev` (D) and `kubectl logs app-pod --container=sidecar --namespace=dev` (C) are valid and equivalent kubectl commands. The explanation incorrectly dismisses C on the grounds that the CKAD exam prefers shorthand; however, CKAD accepts both short and long flags. Therefore, the question is ambiguous and should be corrected to accept both C and D.

Answer

kubectl logs sidecar -p app-pod -n dev

Answer

kubectl logs app-pod -n dev

Question 4

You want to view the resource usage of all pods running on a node named 'node01'. Which command should you use?

Accepted Answer

kubectl top pods --all-namespaces --field-selector spec.nodeName=node01. `kubectl top pods` retrieves real-time CPU and memory usage metrics for pods, and the `--field-selector spec.nodeName=node01` filter restricts the output to only pods scheduled on the specified node. This directly answers the requirement to view resource usage of all pods on 'node01'.

Answer

kubectl top nodes node01

Answer

kubectl get pods -o wide --all-namespaces --field-selector spec.nodeName=node01

Answer

kubectl describe node node01 | grep -A 10 'Non-terminated Pods'

Question 5

You need to debug a pod that is crashing immediately upon start. You cannot exec into the container because it exits before you can run commands. Which approach should you use to inspect the container's file system?

Accepted Answer

kubectl debug -it pod-name --image=busybox --target=container-name. The correct approach is to use 'kubectl debug' with an ephemeral container (option A). This command creates a temporary container in the same pod, sharing the same volumes and process namespace (if requested), allowing you to inspect the filesystem even when the original container has crashed and exited. Option B fails because the container exits before 'exec' can run. Option C only retrieves logs from the previous instance, not filesystem access. Option D displays pod metadata and events, not filesystem contents.

Answer

kubectl exec -it pod-name -- /bin/sh

Answer

kubectl logs pod-name --previous

Answer

kubectl describe pod pod-name

Question 6

Which kubectl command streams logs from a pod named 'web-pod' in real-time?

Accepted Answer

kubectl logs -f web-pod. `kubectl logs -f web-pod` uses the `-f` (follow) flag to stream logs from the pod in real-time, similar to `tail -f` in Linux. This flag keeps the connection open and continuously outputs new log lines as they are written by the container.

Answer

kubectl logs --previous web-pod

Answer

kubectl logs --tail web-pod

Answer

kubectl logs web-pod --all-containers

Question 7

A developer wants to debug a container that has crashed and is no longer running. Which command allows them to start an ephemeral container in the same pod for debugging?

Accepted Answer

kubectl debug -it --image=busybox --target=. To debug a container that is no longer running, the recommended approach is to create a copy of the pod with a different command via `kubectl debug -it --copy-to= --container= --image=busybox -- sh`, or add an ephemeral container without `--target` (e.g., `kubectl debug -it --image=busybox`). Option B with `--target` will not work because the target container is not running.

Answer

kubectl attach <pod>

Answer

kubectl run debug --image=busybox -it --rm

Answer

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

Question 8

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. The pod is in CrashLoopBackOff with an OOMKilled message, which means the container's memory usage exceeded its configured memory limit. The most appropriate action is to increase the memory limit in the pod's container resource specification so the container has enough memory to run without being terminated by the Out-Of-Memory (OOM) killer.

Answer

Delete and recreate the pod to clear the crash loop

Answer

Increase the CPU request for the container

Answer

Delete the namespace and redeploy all workloads

Question 9

You are debugging a pod that is crashing immediately on startup. You want to run an ephemeral container for debugging while the pod is running. Which command should you use?

Accepted Answer

kubectl debug -it pod --image=busybox --target=crashing-container. `kubectl debug` with the `--target` flag allows you to attach an ephemeral container to a running pod that is crashing on startup, targeting the specific container that is failing. Ephemeral containers are designed for troubleshooting when `kubectl exec` is not possible (e.g., the container has no shell or crashes immediately), and they run in the pod's namespaces without restarting the pod.

Answer

kubectl run debug --image=busybox -it --rm

Answer

kubectl attach pod

Answer

kubectl exec -it pod -- /bin/sh

Question 10

You have a pod with two containers: app and sidecar. The sidecar logs are verbose and you want to view only the app container logs. Which command should you use?

Accepted Answer

kubectl logs pod-name --container app. Both `kubectl logs pod-name --container app` and `kubectl logs pod-name -c app` correctly specify the container named 'app' in a multi-container pod. The `--container` flag is the long form of `-c`. Without a container flag, `kubectl logs` defaults to the first container in the pod spec, which may not be the app container. Option B is incorrect because it does not target a specific container, and option D incorrectly uses a label selector.

Answer

kubectl logs pod-name

Answer

kubectl logs -l app=pod-name

Question 11

Which TWO of the following are valid types of probes in Kubernetes?

Accepted Answer

Startup probe. Kubernetes officially defines three probe types: liveness, readiness, and startup probes. Option B (Startup probe) is correct because it checks whether a container application has started successfully, disabling liveness and readiness checks until it succeeds, which is useful for slow-starting containers. Option C (Liveness probe) is correct because it determines whether a container is still running; if it fails, the kubelet restarts the container according to the pod's restartPolicy. Option E (Readiness probe) is correct because it determines whether a container is ready to accept traffic; if it fails, the pod's IP is removed from the endpoints of matching Services. Option A (Survival probe) is not a Kubernetes probe type—no such probe exists in the API. Option D (Health probe) is not a distinct Kubernetes probe type; it is a generic term that could loosely refer to liveness or readiness but is not an official probe kind.

Answer

Survival probe

Answer

Health probe

Question 12

You want to view the logs of a pod named 'web-pod' that has two containers: 'nginx' and 'sidecar'. Which command correctly retrieves the logs from the 'nginx' container?

Accepted Answer

kubectl logs web-pod -c nginx. The correct command uses the proper syntax: `kubectl logs -c `. Option B follows this syntax correctly. Option A places the container flag before the pod name, which is invalid. Option C omits the -c flag, which is required when the pod has multiple containers. Option D uses the long form --container, which is valid but the question expects the short form as seen in B. Therefore, B is the best answer.

Answer

kubectl logs -c nginx web-pod

Answer

kubectl logs web-pod nginx

Answer

kubectl logs web-pod --container nginx

Question 13

Which TWO of the following are valid liveness probe types in Kubernetes?

Accepted Answer

tcpSocket. Option B (tcpSocket) is correct because Kubernetes supports a tcpSocket liveness probe handler that attempts a TCP connection to the specified port on the container; if the connection succeeds, the probe is considered successful. Option D (httpGet) is correct because the httpGet handler performs an HTTP GET request against a path and port on the container, treating HTTP response codes 200-399 as success. Option A (command) is not a valid probe type name; the actual exec handler runs a command inside the container, but it is called exec, not command. Option C (portCheck) is not a Kubernetes probe handler; port checking is accomplished via tcpSocket. Option E (grpc) is not a valid liveness probe type in the Kubernetes API, even though gRPC health checking exists as a separate concept.

Answer

command

Answer

portCheck

Answer

grpc

Question 14

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. The pod is in CrashLoopBackOff due to OOMKilled, meaning the container exceeded its memory limit and was terminated by the Linux kernel's Out-Of-Memory (OOM) killer. The most appropriate action is to increase the memory limit in the pod's container resource specification, as this directly addresses the root cause—insufficient memory allocation—without requiring a full redeployment or affecting other workloads.

Answer

Delete and recreate the pod to clear the crash loop

Answer

Increase the CPU request for the container

Answer

Delete the namespace and redeploy all workloads

Question 15

A pod named 'web-app' is experiencing high CPU usage. You want to investigate which process inside the container is consuming the most CPU. Which command should you run?

Accepted Answer

kubectl exec web-app -- top. `kubectl exec web-app -- top` runs the `top` command inside the container of the pod 'web-app', which displays real-time process-level CPU usage. This allows you to identify the specific process consuming the most CPU, directly addressing the question's requirement to investigate inside the container.

Answer

kubectl logs -f web-app

Answer

kubectl describe node

Answer

kubectl top pod web-app