KCNA Practice Test 2 — 10 Questions

Question 1

What does the 'kubectl logs' command retrieve?

Accepted Answer

Container logs. The 'kubectl logs' command retrieves the standard output (stdout) and standard error (stderr) streams from a container running in a pod. It directly accesses the container's log files on the node (e.g., /var/log/pods/...) or streams them from the container runtime. This is the primary way to debug application issues in Kubernetes.

Answer

Audit logs

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Cluster events

Answer

Node logs

Question 2

What is the primary purpose of a liveness probe in a container?

Accepted Answer

To check if the container is still alive; restart if not. The primary purpose of a liveness probe is to determine whether a container is still running and healthy. If the probe fails, the kubelet kills the container and restarts it according to the pod's restart policy, ensuring self-healing. This is distinct from readiness probes, which control traffic routing, and resource checks, which are handled by metrics servers or cAdvisor.

Answer

To check resource usage like CPU and memory

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To check if the container is ready to serve traffic

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To check if the pod is scheduled on the correct node

Question 3

Which TWO of the following are required fields when defining a container in a Kubernetes Pod spec? (Choose 2)

Accepted Answer

image. In a Kubernetes Pod spec, the `name` and `image` fields are mandatory for each container definition. The `name` field uniquely identifies the container within the Pod, and the `image` field specifies the container image to run (e.g., `nginx:1.25`). Without these two fields, the Pod creation will fail with a validation error from the Kubernetes API server.

Answer

env

Answer

resources

Answer

ports

Question 4

A Deployment named 'myapp' is managing a ReplicaSet. You need to update the application image to version 2.0. What is the recommended approach?

Accepted Answer

Update the Deployment's pod template image to version 2.0. The recommended approach to update a Deployment's application image is to modify the pod template in the Deployment specification. The Deployment controller then automatically performs a rolling update, creating a new ReplicaSet with the updated image and gradually scaling down the old ReplicaSet, ensuring zero-downtime updates and maintaining desired replica count.

Answer

Scale down the Deployment to 0 replicas, then scale up with the new image

Answer

Delete the existing ReplicaSet and create a new one with the updated image

Answer

Directly update the pods in the ReplicaSet by using 'kubectl edit pod'

Question 5

A team wants to use feature flags to control the rollout of a new feature in a Kubernetes-deployed microservice. Which tool is specifically designed for managing feature flags in cloud-native applications?

Accepted Answer

LaunchDarkly. LaunchDarkly is a feature management platform specifically designed for managing feature flags in cloud-native applications. It allows for controlled rollouts and A/B testing. Argo Rollouts focuses on progressive delivery (canary, blue-green deployments), not feature flags. Helm is a package manager for Kubernetes. Kustomize is for configuration management. Therefore, option B (LaunchDarkly) is correct.

Answer

Helm

Answer

Kustomize

Answer

Argo Rollouts

Question 6

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. The error 'PodInitializing' indicates that the pod's init containers are still running or the main container is waiting for init containers to complete. During this phase, the container has not started, so logs are not yet available. Option D correctly identifies that the pod is initializing and logs cannot be retrieved until the container enters the 'Running' state.

Answer

The container is running but producing no output

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The container runtime is failing to start the container

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The container has crashed and is restarting

Question 7

Which resource in Kubernetes is used to expose a set of pods as a network service?

Accepted Answer

Service. A Service in Kubernetes provides a stable network endpoint (IP address and DNS name) to expose a set of pods, which are ephemeral and can be replaced. Services use selectors to identify target pods and load-balance traffic across them, enabling reliable communication within or outside the cluster.

Answer

Pod

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Deployment

Answer

Ingress

Question 8

A company is adopting a GitOps workflow for their Kubernetes deployments. They want to ensure that the cluster state always matches the desired state defined in a Git repository. Which tool is specifically designed for this purpose?

Accepted Answer

Argo CD. Argo CD is a declarative, GitOps continuous delivery tool specifically designed for Kubernetes that automatically synchronizes the live cluster state with the desired state defined in a Git repository. It continuously monitors the cluster and Git, applying any drift to ensure the cluster matches the repository, which is the core requirement of a GitOps workflow.

Answer

Helm

Answer

Kustomize

Answer

Prometheus

Question 9

Which TWO of the following are core principles of cloud native architecture? (Choose two.)

Accepted Answer

Containerization. Containerization (Option D) is a core principle of cloud native architecture because it packages applications and their dependencies into isolated, lightweight containers, enabling consistent deployment across environments and efficient resource utilization. This aligns with the cloud native goal of portability and scalability, as containers can be orchestrated by platforms like Kubernetes to manage dynamic workloads.

Answer

Manual infrastructure provisioning

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Monolithic application design

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Tight coupling between services

Question 10

Which Kubernetes resource is best suited for running a batch processing job that must complete successfully exactly once?

Accepted Answer

Job. A Kubernetes Job is designed specifically for batch processing tasks that need to run to completion exactly once. It creates one or more Pods and ensures that a specified number of them successfully terminate, making it ideal for workloads like data processing or backups that must finish without retries or restarts.

Answer

DaemonSet

Answer

Deployment

Answer

CronJob