KCNA Cloud Native Application Delivery Practice Test 4 — 15 Questions

Question 1

A team uses Flux with the Source Controller and Kustomize Controller. They update a YAML file in Git to change a Deployment's replica count. What describes the synchronization flow?

Accepted Answer

The Kustomize Controller fetches the source and applies the rendered manifests. Flux Source Controller fetches changes from Git; Kustomize Controller reconciles the kustomization and applies to the cluster.

Answer

The Source Controller directly applies the manifest to the cluster

Answer

Flux uses HelmReleases to apply changes

Answer

Flux requires a manual kubectl apply to sync

Question 2

What is Helm's role in Kubernetes?

Accepted Answer

A package manager for Kubernetes applications. Helm is a package manager that simplifies deploying and managing Kubernetes applications using charts.

Answer

A CI/CD server

Answer

A security scanner for container images

Answer

A monitoring and logging tool

Question 3

During a canary deployment using Argo Rollouts, how does the tool determine the success of the canary before promoting it?

Accepted Answer

By analyzing predefined metrics (e.g., error rate) via an AnalysisTemplate. Argo Rollouts uses metrics from a service mesh or monitoring to analyze the canary's health and decide whether to proceed.

Answer

By checking the rollout's status field in the YAML

Answer

By requiring manual approval via a webhook

Answer

By comparing the ReplicaSet's age to a threshold

Question 4

A developer runs 'helm upgrade --install myapp ./mychart' and sees the release status is 'failed'. What is the most likely cause?

Accepted Answer

The chart contains invalid Kubernetes manifests. A failed Helm upgrade usually means the Kubernetes API rejected the manifests (e.g., invalid YAML, resource conflict).

Answer

The Tiller pod is not running

Answer

The Helm binary is outdated

Answer

The namespace does not exist

Question 5

When using Kustomize, how do you apply a common label to all resources in the base?

Accepted Answer

By setting 'commonLabels' in the kustomization.yaml. Kustomize's commonLabels field adds labels to all resources, including selectors.

Answer

By editing each YAML file individually

Answer

By using the 'patches' field to add labels

Answer

By using a Helm chart instead of Kustomize

Question 6

Which deployment strategy updates pods incrementally, replacing old pods with new ones while ensuring availability?

Accepted Answer

Rolling update. The Rolling update strategy is the correct answer because it incrementally replaces old pods with new ones while maintaining application availability. In Kubernetes, a rolling update updates pods one by one (or in small batches), ensuring that a specified number of pods remain available throughout the process. This is achieved by gradually scaling down the old ReplicaSet and scaling up the new one, controlled by parameters like `maxSurge` and `maxUnavailable` in the Deployment spec.

Answer

Canary deployment

Answer

Blue-green deployment

Answer

Recreate

Question 7

A container image is being pushed to a private registry. What is the correct workflow?

Accepted Answer

Build, tag, push. The standard workflow is: build image, tag it with registry URL, then push to registry.

Answer

Push first, then build

Answer

Push, tag, build

Answer

Tag after push

Question 8

In a CI pipeline, image scanning is integrated to detect vulnerabilities. What is the best practice when a critical vulnerability is found in a base image?

Accepted Answer

Fail the pipeline and notify the team to fix the base image. The pipeline should fail so that the vulnerability is addressed before deployment, preventing insecure images from reaching production.

Answer

Deploy to production and patch later

Answer

Automatically patch the image in the pipeline

Answer

Ignore the vulnerability and proceed with deployment

Question 9

Which DORA metric measures how quickly code changes are deployed to production?

Accepted Answer

Lead time for changes. Lead time for changes measures the time from code commit to running in production.

Answer

Mean time to recovery (MTTR)

Answer

Change failure rate

Answer

Deployment frequency

Question 10

What is the purpose of values.yaml in a Helm chart?

Accepted Answer

To store default configuration values for the chart. values.yaml provides default configuration values that can be overridden at install/upgrade time.

Answer

To specify the chart metadata

Answer

To define the Kubernetes resources to create

Answer

To define the release name

Question 11

Which TWO statements are true about ArgoCD's health status?

Accepted Answer

ArgoCD can be configured to perform automatic rollback on health degradation. ArgoCD assesses health based on Kubernetes resource status and can take actions when health degrades.

Answer

ArgoCD only supports health checks for Deployments

Answer

Health status is only determined by the application's YAML definition

Answer

A healthy application always means the sync status is 'Synced'

Question 12

Which THREE are common features of progressive delivery?

Accepted Answer

Feature flags to enable/disable features. Progressive delivery uses gradual rollout, feature flags, and analysis to reduce risk.

Answer

All-at-once deployment

Answer

Manual verification for every change

Question 13

Which TWO actions can improve the DORA metric 'Mean Time to Recovery (MTTR)'?

Accepted Answer

Using feature flags to disable faulty code quickly. Reducing MTTR involves quick detection and rollback or fix of failures.

Answer

Increasing deployment frequency

Answer

Slowing down the release cycle

Answer

Adding more manual approval steps

Question 14

What is the primary purpose of a container registry in a CI/CD pipeline?

Accepted Answer

To host container images for deployment. A container registry stores and distributes container images. After building and scanning, images are pushed to a registry so that deployment tools can pull them to run containers.

Answer

To manage Kubernetes secrets

Answer

To store source code and trigger builds

Answer

To run CI/CD pipelines

Question 15

In GitOps with ArgoCD, what does 'self-healing' refer to?

Accepted Answer

Automatically reverting manual changes to match the Git repository. Self-healing automatically reverts any manual changes made to the live cluster state back to the desired state defined in Git, ensuring configuration drift is corrected.

Answer

Automatically scaling applications based on metrics

Answer

Automatically restarting failed pods

Answer

Automatically updating the Git repository when changes are made in the cluster