KCNA Timed Practice Test 3 — 10 Questions

Question 1

Which kubectl command would you use to view the logs of a container named 'web' inside a Pod named 'app-12345'?

Accepted Answer

kubectl logs app-12345 -c web. Option A is correct because `kubectl logs app-12345 -c web` explicitly specifies the container name 'web' within the Pod 'app-12345' using the `-c` flag. This is the standard syntax for viewing logs of a specific container in a multi-container Pod, as the `kubectl logs` command defaults to the first container if `-c` is omitted.

Answer

kubectl logs -p web app-12345

Answer

kubectl logs app-12345 --container=web

Answer

kubectl logs web app-12345

Question 2

Which two of the following are valid ways to expose a Deployment externally to the internet? (Select TWO)

Accepted Answer

Create a Service of type LoadBalancer. Option C is correct because a Service of type LoadBalancer provisions an external load balancer (e.g., in cloud environments like AWS, GCP, or Azure) that assigns a public IP or DNS name, making the Deployment directly accessible from the internet. This is a standard method for exposing services externally in Kubernetes.

Answer

Create a Service of type ClusterIP

Answer

Create an Ingress resource

Answer

Create a Headless Service

Question 3

A Deployment is configured with 'replicas: 4' and 'strategy.type: RollingUpdate'. You update the container image. What behavior does the Deployment exhibit?

Accepted Answer

New Pods are created before old ones are terminated, one at a time. With a RollingUpdate strategy, the Deployment controller replaces old Pods with new ones incrementally to ensure zero downtime. By default, it creates new Pods before terminating old ones (maxSurge=25%, maxUnavailable=25%), so one new Pod is created first, then one old Pod is terminated, repeating until all 4 Pods run the new image.

Answer

The Deployment creates 8 Pods total, 4 old and 4 new

Answer

All 4 Pods are deleted immediately and then 4 new Pods are created

Answer

The update is paused until manually resumed

Question 4

Which component is responsible for running containers on a Kubernetes node?

Accepted Answer

kubelet. The kubelet is the primary node agent that runs on each Kubernetes node. It is responsible for ensuring that containers are running in a Pod as expected, by interacting with the container runtime (e.g., containerd or CRI-O) to start, stop, and monitor containers based on PodSpecs received from the API server.

Answer

kube-controller-manager

Answer

kube-proxy

Answer

kube-apiserver

Question 5

Which of the following is a benefit of using an orchestrator like Kubernetes?

Accepted Answer

Automatic scaling based on CPU utilization. Kubernetes, as a container orchestrator, provides built-in Horizontal Pod Autoscaling (HPA) that automatically adjusts the number of pod replicas based on observed CPU utilization (or custom metrics). This is a core benefit because it allows applications to handle varying load without manual intervention, improving resource efficiency and availability.

Answer

Direct access to the host kernel for performance tuning

Answer

Guaranteed zero downtime for all updates

Answer

Manual scaling based on traffic spikes

Question 6

What is the primary benefit of containers over virtual machines?

Accepted Answer

Containers are more portable and lightweight because they share the host OS kernel. Containers are more portable and lightweight than virtual machines because they share the host OS kernel, eliminating the need for a separate guest OS per instance. This shared kernel approach reduces resource overhead (CPU, memory, and disk) and enables faster startup times, as containers only package the application and its dependencies without duplicating the operating system.

Answer

Containers provide stronger isolation than VMs

Answer

Containers use more disk space than VMs

Answer

Containers require a hypervisor to run

Question 7

Which component of an API gateway pattern is responsible for routing requests to the appropriate microservice based on the request path?

Accepted Answer

API Gateway. The API gateway acts as a reverse proxy and routes requests to the correct backend service.

Answer

Load balancer

Answer

Service registry

Answer

Sidecar proxy

Question 8

A developer wants to run a container image locally for testing before deploying to a Kubernetes cluster. Which tool is most appropriate for this task?

Accepted Answer

Docker. Docker is a widely used tool for building and running containers locally. While Kubernetes can run containers, it is overkill for local testing of a single container.

Answer

Ansible

Answer

Kubernetes

Answer

Terraform

Question 9

Which of the following is true about Kubernetes Namespaces?

Accepted Answer

Namespaces allow you to divide cluster resources between multiple users. Namespaces provide a logical separation of resources within a cluster, allowing multiple teams or projects to coexist.

Answer

Objects in different namespaces cannot communicate with each other

Answer

Namespaces are global across all clusters

Answer

Namespaces provide network isolation by default

Question 10

You want to deploy a stateless web application that should maintain 5 running instances at all times. You need to support rolling updates and rollbacks. Which Kubernetes resource is most appropriate?

Accepted Answer

Deployment. A Deployment manages a ReplicaSet and provides declarative updates, rolling updates, and rollback capabilities, making it ideal for stateless applications.

Answer

DaemonSet

Answer

ReplicaSet

Answer

StatefulSet