KCNA Kubernetes Fundamentals Practice Test 3 — 15 Questions

Question 1

A user wants to view the logs from a container named 'app' inside a multi-container pod named 'web'. Which kubectl command should be used?

Accepted Answer

kubectl logs web -c app. 'kubectl logs web -c app' retrieves logs from the 'app' container inside the multi-container pod 'web'. The -c (or --container) flag selects the container. Option B and D reverse or misplace the arguments — kubectl logs takes the pod name first with the container specified via a flag, not positionally. Option C is invalid because 'kubectl get logs' is not a kubectl command; logs is a top-level kubectl verb, not a resource that can be retrieved with get.

Answer

kubectl logs app web

Answer

kubectl get logs web -c app

Answer

kubectl logs web app

Question 2

What is the smallest deployable unit in Kubernetes?

Accepted Answer

Pod. A Pod is the smallest and simplest unit in the Kubernetes object model. It represents a single instance of a running process in the cluster and encapsulates one or more containers with shared storage and network resources. Containers are not directly scheduled onto Nodes; instead, Kubernetes always schedules and manages Pods as the atomic unit of deployment.

Answer

Node

Answer

Deployment

Answer

Container

Question 3

A Pod has two containers. You need to see the logs of the second container named 'sidecar'. Which kubectl command should you use?

Accepted Answer

kubectl logs pod-name --container sidecar. The command `kubectl logs pod-name --container sidecar` (option A) explicitly specifies the sidecar container. While `-c sidecar` is also a valid shorthand, this question expects the command as listed in option A. Both forms achieve the same result, but in this single-choice format, option A is the designated correct answer.

Answer

kubectl logs sidecar pod-name

Answer

kubectl logs pod-name sidecar

Answer

kubectl logs pod-name -c sidecar

Question 4

You have a Deployment named 'web-app' running three replicas. You need to scale it to five replicas. Which kubectl command accomplishes this?

Accepted Answer

kubectl scale deployment web-app --replicas=5. The correct command to change the number of replicas in a Deployment is `kubectl scale deployment web-app --replicas=5`. This directly instructs the Kubernetes API to update the Deployment's `.spec.replicas` field, causing the ReplicaSet controller to adjust the number of Pods to match the desired count.

Answer

kubectl set deployment web-app replicas=5

Answer

kubectl patch deployment web-app -p '{"replicas":5}'

Answer

kubectl update deployment web-app --replicas=5

Question 5

What is the smallest deployable unit in Kubernetes that can be created and managed?

Accepted Answer

Pod. The Pod is the smallest and simplest unit in the Kubernetes object model, representing a single instance of a running process in the cluster. A Pod encapsulates one or more containers, shared storage, and a unique cluster IP, and it is the atomic unit of scheduling, scaling, and management. Deployments and Services are higher-level abstractions that manage Pods, not the smallest deployable unit themselves.

Answer

Deployment

Answer

Service

Answer

Container

Question 6

What is the smallest deployable unit in Kubernetes?

Accepted Answer

Pod. The Pod is the smallest and simplest unit in the Kubernetes object model. It represents a single instance of a running process in the cluster and encapsulates one or more containers with shared storage and network resources. Deployments manage ReplicaSets, which in turn manage Pods, but the Pod itself is the atomic deployable unit.

Answer

Deployment

Answer

Node

Answer

Container

Question 7

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` is the dedicated command for updating the container image of a running Deployment without modifying the entire manifest. It directly updates the Deployment's pod template spec, triggering a rolling update to replace pods with the new image.

Answer

kubectl replace -f deployment.yaml

Answer

kubectl edit deployment <name>

Answer

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

Question 8

Which TWO statements about Namespaces are correct?

Accepted Answer

Namespaces provide a way to divide cluster resources among multiple users. Option A is correct because Kubernetes Namespaces are explicitly designed to divide cluster resources among multiple users or teams, commonly via ResourceQuota and LimitRange objects scoped to a namespace, enabling multi-tenancy and resource partitioning. Option C is correct because Namespaces provide a logical grouping mechanism to organize cluster objects (e.g., pods, services, deployments) into distinct virtual clusters, making management and naming easier. Option B is incorrect because Namespaces are not a strong security boundary by default; they provide no network isolation or RBAC isolation unless NetworkPolicies and RBAC are explicitly configured, and cluster-scoped resources remain shared. Option D is incorrect because not every resource is namespaced — cluster-scoped resources such as Nodes, PersistentVolumes, StorageClasses, and ClusterRoles exist outside any namespace. Option E is incorrect because resources in different namespaces can communicate freely over the network by default (e.g., via ClusterIP services using the fully qualified domain name service.namespace.svc.cluster.local) unless NetworkPolicies restrict traffic.

Answer

Namespaces act as a strong security boundary by default

Answer

Every resource must be created in a namespace

Answer

Resources in different namespaces cannot communicate with each other

Question 9

What is the smallest deployable unit in Kubernetes that can be created, scheduled, and managed?

Accepted Answer

Pod. A Pod is the smallest and simplest unit in the Kubernetes object model. It represents a single instance of a running process in the cluster and encapsulates one or more containers with shared storage and network resources. Pods are the atomic unit of scheduling, meaning the Kubernetes scheduler places entire Pods onto Nodes, not individual containers.

Answer

Node

Answer

Deployment

Answer

Container

Question 10

You want to create a new Namespace called 'staging' and apply a ResourceQuota to it. Which of the following YAML snippets correctly defines a ResourceQuota that limits total memory to 10Gi and total CPU to 5 cores in namespace 'staging'?

Accepted Answer

apiVersion: v1
kind: ResourceQuota
metadata:
  name: staging-quota
  namespace: staging
spec:
  hard:
    limits.cpu: "5"
    limits.memory: 10Gi. It defines a ResourceQuota with `limits.cpu` and `limits.memory` under `spec.hard`, which restricts the total CPU and memory that all pods in the namespace can consume. The values are specified as strings ("5" for CPU and 10Gi for memory), which is the correct format for ResourceQuota resources in Kubernetes.

Answer

apiVersion: v1
kind: ResourceQuota
metadata:
  name: staging-quota
  namespace: staging
spec:
  hard:
    requests.cpu: "5"
    requests.memory: 10Gi

Answer

apiVersion: v1
kind: LimitRange
metadata:
  name: staging-limits
  namespace: staging
spec:
  limits:
  - default:
      cpu: 5
      memory: 10Gi
    defaultRequest:
      cpu: 1
      memory: 1Gi

Answer

apiVersion: v1
kind: ResourceQuota
metadata:
  name: staging-quota
spec:
  hard:
    cpu: 5
    memory: 10Gi

Question 11

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

Accepted Answer

kube-apiserver. The Kubernetes control plane is the set of components that make global cluster decisions and store cluster state, and it includes the kube-apiserver (A) and etcd (E). The kube-apiserver (A) is the front end of the control plane: it exposes the Kubernetes API, validates and processes REST requests, and is the only component that talks directly to etcd. etcd (E) is the consistent, highly available key-value store that persists all cluster data, including object definitions and state, making it a core control-plane component. The other options are node-level components, not control-plane components: the container runtime (B) and kubelet (D) run on each worker node to execute and manage pods, and kube-proxy (C) runs on each node to implement Service networking via iptables/IPVS rules.

Answer

container runtime

Answer

kube-proxy

Answer

kubelet

Question 12

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 OOMKilled status indicates the container was terminated because it 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 of the CrashLoopBackOff.

Answer

Delete the namespace and redeploy all workloads

Answer

Delete and recreate the pod to clear the crash loop

Answer

Increase the CPU request for the container

Question 13

Which component of the Kubernetes control plane is responsible for storing the cluster state?

Accepted Answer

etcd. etcd is the distributed key-value store that serves as Kubernetes' single source of truth for cluster state. It stores all cluster data, including configuration, desired state, and current state of objects like Pods, Services, and Deployments. The kube-apiserver is the only component that directly communicates with etcd, ensuring consistency and transactional integrity.

Answer

kube-scheduler

Answer

kube-controller-manager

Answer

kube-apiserver

Question 14

Which of the following is true about Kubernetes Namespaces?

Accepted Answer

Namespaces can help organize and manage resources in a cluster. Namespaces in Kubernetes provide a mechanism for isolating groups of resources within a single cluster. They allow you to organize resources like Pods, Services, and Deployments into logical groups, which is especially useful in multi-tenant environments or when managing different environments (e.g., dev, staging, prod) within the same cluster. This makes option A correct.

Answer

Resource names must be unique across all namespaces

Answer

Namespaces provide network isolation between resources

Answer

You must create a namespace before creating any resources

Question 15

You want to update a Deployment's container image from 'nginx:1.20' to 'nginx:1.21' and record the change. Which kubectl command should you use?

Accepted Answer

kubectl set image deployment/nginx nginx=nginx:1.21 --record. The `kubectl set image` command directly updates the container image of a specified deployment, and the `--record` flag annotates the change in the rollout history, allowing you to track the change for auditing or rollback purposes. This is the most efficient way to update the image and record the change without editing the full deployment manifest or reapplying a file.

Answer

kubectl edit deployment nginx

Answer

kubectl apply -f deployment.yaml

Answer

kubectl set image deployment/nginx nginx=nginx:1.21