KCNA Kubernetes Fundamentals Practice Test 4 — 15 Questions

Question 1

Which field in a Deployment YAML specifies the number of pod replicas?

Accepted Answer

spec.replicas. In a Kubernetes Deployment YAML, the `spec.replicas` field directly defines the desired number of pod replicas that the Deployment controller should maintain. This is a top-level field under the Deployment spec, not nested under `template.spec`, because the replica count is a property of the Deployment itself, not of the Pod template.

Answer

spec.template.spec.replicas

Answer

spec.replicaCount

Answer

spec.selector.matchLabels

Question 2

What is the primary purpose of Kubernetes?

Accepted Answer

To automate deployment, scaling, and management of containerized applications. Kubernetes is an open-source container orchestration platform designed to automate the deployment, scaling, and management of containerized applications. It abstracts the underlying infrastructure, allowing users to define desired states (e.g., number of replicas, resource limits) and then continuously reconciles the actual state with that desired state. This core functionality is what makes Kubernetes the industry standard for running production-grade container workloads.

Answer

To provide a graphical user interface for managing containers

Answer

To replace Docker as a container runtime

Answer

To compile source code into container images

Question 3

Which component of the control plane is responsible for persisting the entire cluster state?

Accepted Answer

etcd. etcd is the distributed key-value store that serves as the single source of truth for the entire cluster state, including all objects (Pods, Services, ConfigMaps, etc.), their specifications, and their current status. It is the only component that persists data to disk, ensuring that the cluster can recover its full state after a restart or failure. The kube-apiserver reads from and writes to etcd, but etcd itself is the storage backend.

Answer

kube-scheduler

Answer

kube-controller-manager

Answer

kube-apiserver

Question 4

You have a pod that is scheduled on a node with insufficient memory. The pod's manifest does not have a memory limit, but the node is under memory pressure. What is likely to happen to the pod?

Accepted Answer

The pod will be terminated with a 'OOMKilled' status. When a pod has no memory limit, its container can use memory up to the node's capacity. If the node experiences memory pressure, the kernel's Out-Of-Memory (OOM) killer may terminate the container to free memory, resulting in an 'OOMKilled' status. This is different from kubelet eviction, which typically affects pods with resource limits when they exceed their requests.

Answer

The pod will continue running normally because it has no limit

Answer

The pod will be evicted and rescheduled on a different node

Answer

The pod will be terminated with a 'CrashLoopBackOff' status

Question 5

Which kubectl command is used to view detailed information about a Kubernetes resource?

Accepted Answer

kubectl describe. The `kubectl describe` command retrieves detailed, multi-section information about a specific Kubernetes resource, including events, status conditions, and configuration details. Unlike `kubectl get`, which shows a summary, `kubectl describe` provides a deep dive into the resource's current state, making it the correct choice for viewing detailed information.

Answer

kubectl get

Answer

kubectl exec

Answer

kubectl logs

Question 6

Which component on each worker node is responsible for ensuring that containers are running as specified in the Pod manifest?

Accepted Answer

kubelet. The kubelet is the primary node agent that runs on each worker node. It receives Pod manifests (via the API server or a file) and ensures the containers described in those manifests are running and healthy. It interacts with the container runtime (e.g., containerd) to create, start, and stop containers as needed, continuously reconciling the actual state with the desired state defined in the Pod spec.

Answer

kube-scheduler

Answer

container runtime

Answer

kube-proxy

Question 7

Which two components are part of the Kubernetes control plane? (Select two.)

Accepted Answer

etcd. etcd is a distributed key-value store that serves as the cluster's source of truth, storing all configuration data, state, and metadata. The kube-apiserver is the front-end of the control plane, exposing the Kubernetes API and handling all RESTful requests for cluster operations. Both are essential control plane components that manage and orchestrate the cluster's overall state.

Answer

kube-proxy

Answer

kubelet

Answer

container runtime

Question 8

Which three of the following are true about Services in Kubernetes? (Select three.)

Accepted Answer

A Service provides a stable IP address for a set of pods. A Kubernetes Service provides a stable virtual IP (ClusterIP) that remains constant even as pods are created or destroyed. This decouples clients from the ephemeral nature of pod IPs, ensuring reliable network access to the pod group.

Answer

A Service can store configuration data for applications

Answer

A Service can replace an Ingress for HTTP routing

Question 9

Which two of the following are valid ways to expose a Pod's container port to other resources? (Select two.)

Accepted Answer

Create a Service of type ClusterIP pointing to the Pod's port. A ClusterIP Service provides a stable virtual IP and DNS name that routes traffic to the Pod's container port. This is the standard Kubernetes abstraction for exposing a Pod to other resources within the cluster, as the Service selects the Pod via labels and forwards traffic to the specified targetPort.

Answer

Add a containerPort field in the Pod spec

Answer

Set the pod's hostNetwork to true

Answer

Use kubectl port-forward

Question 10

A Deployment named 'app-deploy' is configured with strategy type: RollingUpdate. You want to update the container image to a new version. What kubectl command should you use?

Accepted Answer

kubectl set image deployment/app-deploy app=new:tag. `kubectl set image` is the dedicated command for updating the container image of an existing deployment without modifying other fields. It directly modifies the deployment's pod template spec to use the new image, triggering a rolling update as defined by the deployment's strategy type.

Answer

kubectl apply -f updated-deployment.yaml

Answer

kubectl edit deployment app-deploy

Answer

kubectl patch deployment app-deploy -p '{"spec":{"template":{"spec":{"containers":[{"name":"app","image":"new:tag"}]}}}}'

Question 11

A user creates a Pod with a PersistentVolumeClaim (PVC) that requests 5Gi of storage. The cluster has two PersistentVolumes (PVs): PV1 (3Gi, AccessModes: ReadWriteOnce) and PV2 (10Gi, AccessModes: ReadOnlyMany). The PVC specifies storageClassName: "" and AccessModes: ReadWriteOnce. Which PV will bind to the PVC?

Accepted Answer

Neither PV will bind; the PVC will remain pending.. The PVC specifies storageClassName: "", which means it requires a PV with the same empty storage class (i.e., a statically provisioned PV without a StorageClass). PV1 has 3Gi capacity, which is less than the requested 5Gi, so it fails capacity matching. PV2 has ReadOnlyMany access mode, which does not match the PVC's ReadWriteOnce. Since neither PV satisfies all binding criteria (capacity, access modes, and storage class), the PVC remains Pending.

Answer

PV2 will bind because it has sufficient capacity.

Answer

PV1 will bind because it has matching AccessModes.

Answer

Both PVs will bind to satisfy the request.

Question 12

You have a Deployment that must run exactly one replica on each node in the cluster for logging purposes. Which Kubernetes resource should you use?

Accepted Answer

DaemonSet. A DaemonSet ensures that exactly one replica of a Pod runs on every node in the cluster, including when nodes are added or removed. This makes it the ideal resource for cluster-wide logging, monitoring, or other node-level agents that must be present on each node.

Answer

Job

Answer

Deployment

Answer

StatefulSet

Question 13

Which two components are part of the Kubernetes worker node? (Select TWO)

Accepted Answer

kubelet. The kubelet is the primary node agent that runs on every worker node. It registers the node with the Kubernetes control plane, receives Pod specifications from the API server via the kube-apiserver, and ensures that the containers described in those PodSpecs are running and healthy. It also reports node and Pod status back to the control plane using the Kubernetes API.

Answer

kube-controller-manager

Answer

etcd

Answer

kube-scheduler

Question 14

You want to view the logs of a running pod named 'my-pod'. Which kubectl command should you use?

Accepted Answer

kubectl logs my-pod. The `kubectl logs my-pod` command is the correct way to retrieve the standard output and standard error logs from a running pod in Kubernetes. It directly fetches the container logs from the kubelet, which are stored on the node and rotated by the container runtime (e.g., containerd or CRI-O). This is the dedicated command for log inspection, as defined in the Kubernetes CLI documentation.

Answer

kubectl exec my-pod -- cat /var/log/container.log

Answer

kubectl get pod my-pod -o yaml

Answer

kubectl describe pod my-pod

Question 15

What is the primary purpose of Kubernetes?

Accepted Answer

To automate deployment, scaling, and operations of application containers across clusters. Kubernetes is an open-source container orchestration platform designed to automate the deployment, scaling, and management of containerized applications across clusters of hosts. Its primary purpose is to abstract the underlying infrastructure and provide declarative configuration, self-healing, load balancing, and rolling updates, which directly aligns with option C.

Answer

To replace Docker as a container runtime

Answer

To provide a graphical user interface for managing containers

Answer

To provide a virtual machine management platform