KCNA Base and Overlay Practice Question
Which TWO statements are true about Kustomize? (Choose 2)
⚠ Common exam trap
The trap here is that candidates might confuse Kustomize with Helm, thinking Kustomize uses Go templating or can package Helm charts, but Kustomize is template-free and focuses on overlays and patches.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
It supports patching Kubernetes resources via strategic merge patches or JSON patches.
Option A is correct because Kustomize natively supports customizing Kubernetes resources through patches, including strategic merge patches (which merge by resource keys) and JSON patches (RFC 6902 operations), applied via the patchesStrategicMerge and patchesJson6902 fields in kustomization.yaml. Option D is correct because Kustomize's core design is a base-and-overlay model, where a base holds common manifests and overlays reference the base to apply environment-specific customizations without duplicating YAML. Option B is not correct because canary traffic routing is handled by service meshes or progressive delivery tools like Argo Rollouts or Flagger, not Kustomize, which only renders manifests. Option C is not correct because Kustomize deliberately avoids Go templating; it uses declarative YAML overlays and patches, unlike Helm which uses Go templates. Option E is not correct because packaging and deploying Helm charts is the role of Helm itself, not Kustomize, although the two tools can be used together.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
It supports patching Kubernetes resources via strategic merge patches or JSON patches.
Why this is correct
Kustomize's patch transformers apply strategic merge patches, which use Kubernetes merge keys to combine list items by name, or JSON patches, which use RFC 6902 operations for precise edits. This satisfies the stem's requirement for a true statement, as both patch types are core, documented Kustomize features.
- ✗
It automatically handles canary traffic routing.
Why it's wrong here
Kustomize performs declarative YAML overlay and patch customisation; it has no traffic-splitting controller or ingress integration, so cannot shift request percentages between versions. It is tempting because overlays can vary replica counts or labels per environment, which teams sometimes mistake for progressive delivery. Canary routing requires a service mesh or ingress controller such as Flagger or Argo Rollouts.
- ✗
It relies on Go templating to generate Kubernetes manifests.
Why it's wrong here
Kustomize uses declarative overlays and strategic-merge patches on plain YAML; it does not process Go templates, which Helm uses. It is tempting because templating is common in manifest tooling, and Go templating would be correct when parameterised chart generation is required.
- ✓
It uses a base and overlay model to manage environment-specific configurations.
Why this is correct
Kustomize layers a base containing shared manifests with overlays that patch only environment-specific values, such as replicas or image tags. This satisfies the need to manage per-environment configuration without duplicating or templating the entire YAML set.
- ✗
It can be used to package and deploy Helm charts.
Why it's wrong here
Kustomize overlays and patches plain YAML; it neither packages nor deploys Helm charts, which Helm itself handles through charts and releases. It is tempting because both tools manage Kubernetes manifests, and Kustomize would be correct for layering environment-specific customisations without templating.
Go deeper
Related to this question
Learn chapter
Kubernetes Overview and Core Components
Key term
ReplicaSet and Replication
A ReplicaSet ensures a specified number of identical pod instances are running at all times in Kubernetes, using replication to maintain availability and stability.
Key term
Helm Charts
Helm Charts are packages of pre-configured Kubernetes resources that let you install, upgrade, and manage complex applications on a Kubernetes cluster with a single command.
About these practice questions
This KCNA question is part of Courseiva's 930-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CNCF exam blueprint
This KCNA practice question is part of Courseiva's free CNCF certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the KCNA exam.