KCNA Kubernetes Fundamentals Practice Test 14 — 15 Questions

Question 1

You create a Deployment with 'replicas: 3' and update the pod template without changing the selector. After the update, you notice that only the new Pods are running, but old Pods have been terminated. What is the default update strategy?

Accepted Answer

RollingUpdate. The default strategy for Deployments is RollingUpdate, which gradually replaces old Pods with new ones without downtime, and by default it keeps no old Pods running after the update completes.

Answer

OnDelete

Answer

BlueGreen

Answer

Recreate

Question 2

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

Accepted Answer

kube-apiserver. The kube-apiserver is the front-end of the Kubernetes control plane, exposing the Kubernetes API for all cluster operations. The kube-scheduler is responsible for assigning newly created pods to nodes based on resource availability and policy constraints. Both are essential control plane components that manage cluster state and scheduling decisions.

Answer

kube-proxy

Answer

kubelet

Answer

container runtime

Question 3

Which THREE of the following are valid ways to expose a Service to external traffic? (Select exactly three.)

Accepted Answer

Ingress. NodePort, LoadBalancer, and Ingress are methods to expose services externally. ClusterIP is internal only. ExternalName maps to an external DNS name but does not expose via external IP.

Answer

ExternalName

Answer

ClusterIP

Question 4

Which TWO of the following are correct about the 'kubectl apply' command compared to 'kubectl create'? (Select exactly two.)

Accepted Answer

kubectl apply can accept a directory of YAML files with -f. kubectl apply uses declarative object management; it creates the object if it doesn't exist, but also updates existing objects by applying the configuration. The -f flag can be a file or directory.

Answer

kubectl apply requires the --save-config flag to record the last-applied-configuration annotation

Answer

kubectl apply cannot be used on resources that already exist

Answer

kubectl apply can create objects but not update them

Question 5

Which Kubernetes component is the primary entry point for all administrative tasks and API requests?

Accepted Answer

kube-apiserver. The kube-apiserver is the front-end of the Kubernetes control plane and the sole entry point for all administrative tasks and API requests. It validates and processes RESTful API calls (using JSON/YAML over HTTP/HTTPS) before persisting state to etcd or delegating work to other controllers. Without the API server, no kubectl command, automation script, or internal component can interact with the cluster.

Answer

kube-controller-manager

Answer

etcd

Answer

kube-scheduler

Question 6

What is the smallest deployable unit in Kubernetes?

Accepted Answer

Pod. A Pod is the smallest and simplest Kubernetes object. It represents a single instance of a running process.

Answer

Deployment

Answer

Node

Answer

Container

Question 7

Which command is used to view detailed information about a specific pod?

Accepted Answer

kubectl describe pod. kubectl describe pod provides detailed information including events, status, and configuration.

Answer

kubectl exec pod -- /bin/sh

Answer

kubectl logs pod

Answer

kubectl get pod

Question 8

A Deployment manages ReplicaSets. What is the primary benefit of using a Deployment over directly managing ReplicaSets?

Accepted Answer

Deployments support rolling updates and rollbacks. The primary benefit of using a Deployment over directly managing ReplicaSets is that Deployments provide declarative updates for Pods and ReplicaSets, including built-in support for rolling updates and rollbacks. This allows you to update the desired state (e.g., a new container image version) and have the Deployment controller automatically orchestrate the transition, while also enabling you to revert to a previous revision if the update fails. Directly managing ReplicaSets would require manual steps to scale down old ReplicaSets and scale up new ones, and it lacks the automated revision history and rollback capabilities that Deployments offer.

Answer

Deployments can expose services externally

Answer

Deployments automatically configure DNS

Answer

Deployments provide persistent storage

Question 9

You have a Pod with a container that needs to read sensitive data such as a database password. Which Kubernetes resource should you use to store this data?

Accepted Answer

Secret. Secrets are designed to store sensitive information like passwords, tokens, or keys.

Answer

PersistentVolume

Answer

ServiceAccount

Answer

ConfigMap

Question 10

A Pod is stuck in Pending state. Which of the following is the MOST likely cause?

Accepted Answer

No node has enough resources to run the Pod. Pending usually indicates that the scheduler cannot find a suitable node, often due to insufficient resources.

Answer

The Pod's container is crashing

Answer

The container image has a typo

Answer

The Pod's liveness probe is failing

Question 11

Which component on a worker node is responsible for enforcing the network rules and implementing Service abstractions?

Accepted Answer

kube-proxy. kube-proxy runs on each node and handles network proxying and load balancing for Services.

Answer

kubelet

Answer

container runtime

Answer

kube-scheduler

Question 12

You need to update a running Deployment to use a new container image. Which kubectl command should you use?

Accepted Answer

kubectl set image deployment/ =. kubectl set image updates the image of a container in a Deployment.

Answer

kubectl replace -f deployment.yaml

Answer

kubectl edit deployment <name>

Answer

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

Question 13

A Service of type ClusterIP is created. What is the default behavior of this Service?

Accepted Answer

It exposes the Service on a cluster-internal IP. Option D is correct because a ClusterIP Service is the default Kubernetes Service type, which assigns a virtual IP address reachable only within the cluster. Traffic sent to this IP is load-balanced across the Pods selected by the Service's label selector, using iptables or IPVS rules. No external access is provided unless an Ingress or other mechanism is explicitly configured.

Answer

It exposes the Service externally via a cloud load balancer

Answer

It exposes the Service on a static port on each node

Answer

It routes traffic to Pods based on external DNS names

Question 14

You have a Deployment that manages 3 replicas. You want to perform a rolling update with a maximum of 2 Pods unavailable during the update. Which field should you set in the Deployment spec?

Accepted Answer

spec.strategy.rollingUpdate.maxUnavailable. maxUnavailable in the rolling update strategy controls how many Pods can be unavailable during the update.

Answer

spec.minReadySeconds

Answer

spec.strategy.rollingUpdate.maxSurge

Answer

spec.replicas

Question 15

You run 'kubectl logs my-pod' and see: "Error from server (BadRequest): container "my-container" in pod "my-pod" is waiting to start: PodInitializing". What does this mean?

Accepted Answer

The Pod is in the process of initializing and logs are not yet available. PodInitializing indicates that the Pod is still initializing, e.g., pulling images or running init containers. Logs are not available until the container starts.

Answer

The container is running but producing no output

Answer

The container runtime is failing to start the container

Answer

The container has crashed and is restarting