CKA Practice Test 39 — 15 Questions

Question 1

Which CronJob schedule expression runs a job every day at midnight (00:00)?

Accepted Answer

0 0 * * *. The CronJob schedule expression '0 0 * * *' specifies minute 0, hour 0 (midnight), every day of the month, every month, and every day of the week. This matches the requirement to run a job daily at 00:00.

Answer

0 * * * *

Answer

0 0 1 * *

Answer

* 0 * * *

Question 2

A Pod is stuck in Pending state. Running 'kubectl describe pod' shows '0/3 nodes are available: 1 node(s) had taint {node-role.kubernetes.io/control-plane: }, 2 node(s) had taint {node-role.kubernetes.io/master: }'. The Pod does not have tolerations. What is the most likely cause?

Accepted Answer

The Pod does not have tolerations for the control-plane or master taints.. The Pod is stuck in Pending state because it does not have tolerations for the taints present on the nodes. The error message explicitly states that 1 node has the control-plane taint and 2 nodes have the master taint. By default, Pods without matching tolerations cannot be scheduled onto tainted nodes. Since all available nodes are tainted, the scheduler has no eligible node to place the Pod, leaving it in Pending.

Answer

The scheduler is not running.

Answer

The Pod requests more CPU than any node can provide.

Answer

The Pod has a node selector that doesn't match any node.

Question 3

A pod is stuck in 'Pending' state. 'kubectl describe pod' shows '0/1 nodes are available: 1 node(s) had taint {node.kubernetes.io/unreachable: }, that the pod didn't tolerate'. What does this indicate?

Accepted Answer

The node is not reachable by the control plane. The error message indicates that the node has a taint of `node.kubernetes.io/unreachable`, which is automatically added by the node controller when the control plane cannot communicate with the node (e.g., due to network failure or kubelet being down). The pod remains in 'Pending' because no node is available that tolerates this taint, meaning the node is unreachable from the control plane. This matches option C.

Answer

The pod has been successfully scheduled to the node

Answer

The node has insufficient resources and is tainted

Answer

The node does not exist

Question 4

Your cluster has three control plane nodes. You suspect the etcd cluster has a leader election issue. Which TWO commands can help diagnose the etcd cluster health and membership? (Choose TWO.)

Accepted Answer

etcdctl endpoint health --cluster. `etcdctl endpoint health --cluster` queries the health status of all etcd endpoints in the cluster, which directly reveals if any node is unreachable or unhealthy—a common symptom of leader election issues. Option E is correct because `etcdctl member list` displays the current cluster membership, including each member's ID, name, peer URLs, and client URLs, allowing you to verify that all expected control plane nodes are properly joined and that no split-brain or quorum loss has occurred.

Answer

etcdctl cluster-status

Answer

etcdctl version

Answer

etcdctl snapshot save snapshot.db

Question 5

Which of the following creates a ConfigMap named 'my-config' from a file 'app.properties'?

Accepted Answer

kubectl create configmap my-config --from-file=app.properties. `kubectl create configmap my-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 (app.properties) 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 my-config --from-literal=app.properties

Answer

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

Answer

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

Question 6

Which command can be used to view resource usage of nodes in a cluster?

Accepted Answer

kubectl top nodes. The 'kubectl top nodes' command displays resource usage (CPU and memory) for nodes in the cluster. It requires the Metrics Server to be installed and running. This command provides a quick view of node utilization.

Answer

kubectl describe nodes

Answer

kubectl top pods

Answer

kubectl get pods --show-resources

Question 7

A new StorageClass 'fast' is created with volumeBindingMode: WaitForFirstConsumer. A PVC using this StorageClass is created but no pod consumes it. What is the state of the PVC immediately after creation?

Accepted Answer

Pending. When a StorageClass uses volumeBindingMode: WaitForFirstConsumer, the PVC will remain in a Pending state until a pod that uses it is scheduled. This is because the volume binding and provisioning are deferred until the first consumer (pod) is created, allowing the scheduler to consider the pod's node constraints when selecting the volume. Since no pod consumes the PVC immediately after creation, it stays Pending.

Answer

Bound

Answer

Lost

Answer

The PVC will not be created

Question 8

You are troubleshooting a connectivity issue between two pods in the same cluster. Pod A cannot reach Pod B's IP. Which command would you run from Pod A to test connectivity?

Accepted Answer

kubectl exec pod-a -- curl . `kubectl exec pod-a -- curl ` runs the `curl` command inside Pod A, directly testing Layer 3 connectivity to Pod B's IP address. This bypasses any service or DNS abstraction and verifies whether the pod network (e.g., CNI plugin like Calico or Flannel) is functioning correctly between the two pods.

Answer

kubectl top pod pod-b

Answer

kubectl logs pod-b

Answer

kubectl describe pod-b

Question 9

You have a Deployment with 3 replicas. You run 'kubectl rollout history deployment web-app' and see revision 2 is current. You want to roll back to revision 1. Which command should you use?

Accepted Answer

kubectl rollout undo deployment/web-app --to-revision=1. `kubectl rollout undo deployment/web-app --to-revision=1` explicitly rolls back the Deployment to revision 1, which is the desired state. The `--to-revision` flag targets a specific revision from the rollout history, ensuring the Deployment's Pod template is reverted to the exact configuration of revision 1.

Answer

kubectl set image deployment/web-app web-app=image:v1

Answer

kubectl rollout history deployment/web-app --revision=1

Answer

kubectl rollout undo deployment/web-app

Question 10

A StatefulSet named 'web' with spec.replicas=3 uses the default pod management policy (OrderedReady). The StatefulSet has persistent volume claims. You run 'kubectl scale statefulset web --replicas=5'. Which statement is TRUE about the new pods?

Accepted Answer

Pods web-3 and web-4 are created sequentially, each with its own PVC. A StatefulSet with the default OrderedReady pod management policy creates pods sequentially, strictly in order from the lowest ordinal index to the highest. When scaling from 3 to 5 replicas, pods web-3 and web-4 are created one after another, each with its own dedicated PersistentVolumeClaim (PVC) as defined in the StatefulSet's volumeClaimTemplates.

Answer

Pods web-3 and web-4 are created in parallel, both sharing the same PVC

Answer

The existing pods are recreated with new PVCs

Answer

Only web-3 is created because the StatefulSet cannot exceed 4 replicas

Question 11

A Job named 'pi' runs a container that computes pi to 2000 digits. The Job's spec has completions=3 and parallelism=2. After some time, you observe that two pods completed successfully, and the third pod is still running. What is the expected behavior when the third pod completes?

Accepted Answer

The Job will be marked as Complete. A Job with `completions=3` and `parallelism=2` is considered complete when the required number of successful pod completions (3) is reached. Since two pods have already completed and the third is still running, once it finishes successfully, the total successful completions will equal the `completions` value, and the Job controller will mark the Job as Complete. The Job does not require all pods to run concurrently or finish simultaneously.

Answer

The Job will restart the completed pods

Answer

The Job will continue to run new pods indefinitely

Answer

The Job will be marked as Failed because parallelism is not fully utilized

Question 12

Which of the following is the default DNS name for a Service named 'api' in namespace 'production'?

Accepted Answer

api.production.svc.cluster.local. In Kubernetes, the default DNS name for a Service follows the pattern `..svc.cluster.local`. For a Service named 'api' in namespace 'production', this resolves to `api.production.svc.cluster.local`. The `svc` subdomain is a fixed component that distinguishes Service DNS records from Pod DNS records, and `cluster.local` is the default cluster domain.

Answer

api.production.cluster.local

Answer

production.api.svc.cluster.local

Answer

api.svc.production.cluster.local

Question 13

A developer reports that a Pod named 'web-pod' in namespace 'frontend' is crashing repeatedly. You run 'kubectl logs web-pod -n frontend' but see no output. Which command should you run next to see the logs from the previous, crashed container instance?

Accepted Answer

kubectl logs web-pod -n frontend --previous. The `kubectl logs --previous` flag retrieves logs from the previous instance of a container in a Pod, which is exactly what you need when the current container has crashed and restarted, leaving no logs from the current instance. Since `kubectl logs web-pod -n frontend` returned no output, the current container likely started fresh after a crash, and the logs from the crashed container are stored in the terminated container's log file. This flag accesses those logs without needing to specify a container name explicitly when there is only one container in the Pod.

Answer

kubectl get events -n frontend --sort-by=.metadata.creationTimestamp

Answer

kubectl logs web-pod -n frontend -c web-pod

Answer

kubectl exec -it web-pod -n frontend -- sh

Question 14

A cluster administrator needs to create a PersistentVolume that can be mounted as a block device (not a filesystem) by a Pod. Which field in the PersistentVolume spec must be set to enable this?

Accepted Answer

volumeMode: Block. Setting `volumeMode: Block` in the PersistentVolume spec specifies that the volume is to be presented as a raw block device, without a filesystem. This allows a Pod to mount the volume as a block device (e.g., `/dev/sdb`) rather than a mounted directory, which is required for applications that need direct access to the underlying storage, such as databases or custom storage engines.

Answer

persistentVolumeReclaimPolicy: Retain

Answer

volumeMode: Filesystem

Answer

accessModes: ReadWriteOnce

Question 15

You create a PriorityClass named 'high-priority' with value 1000000 (one million). A pod uses this PriorityClass. The cluster has limited resources. What scheduling behavior is most likely?

Accepted Answer

The pod may preempt lower-priority pods to be scheduled. PriorityClass with value 1000000 is extremely high (the default max is 1 billion). When a pod with this PriorityClass is submitted and the cluster has limited resources, the Kubernetes scheduler may preempt (evict) lower-priority pods to free resources and schedule this high-priority pod. This is the core behavior of PriorityClass and preemption in Kubernetes.

Answer

The pod will never be preempted by other pods

Answer

The pod will be scheduled only after all lower-priority pods have been scheduled

Answer

The pod will be assigned a higher CPU priority in the kernel