Use Helm and Kustomize to install cluster components
5 minutes
5 Questions
In the domain of Cluster Architecture, Installation, and Configuration for the CKA exam, efficiently managing Kubernetes manifests is critical. Helm and Kustomize are the primary tools used to install and manage cluster components.
Helm acts as the package manager for Kubernetes, analogous to yum …In the domain of Cluster Architecture, Installation, and Configuration for the CKA exam, efficiently managing Kubernetes manifests is critical. Helm and Kustomize are the primary tools used to install and manage cluster components.
Helm acts as the package manager for Kubernetes, analogous to yum or apt in Linux. It packages multiple Kubernetes resources into a single logical unit called a Chart. Helm utilizes a templating engine, allowing administrators to parameterize configuration via a values.yaml file. This is particularly useful for installing complex, third-party cluster components like Ingress Controllers, CNIs, or monitoring stacks (e.g., Prometheus). Instead of manually applying individual YAML files, an administrator runs 'helm install', ensuring version control and easy rollbacks.
Kustomize, integrated natively into kubectl (via 'kubectl apply -k'), takes a template-free approach. It focuses on traversing Kubernetes manifests to add, remove, or update configuration options without forking the original files. It uses a kustomization.yaml file to define a base configuration and applies overlays for specific environments (e.g., development vs. production). This allows for precise patching of resources, such as changing replica counts or namespace definitions, while keeping the base structure intact.
For the CKA, candidates are expected to understand how to utilize these tools to set up the cluster environment. You may need to fetch a specific Helm chart to deploy a service or use Kustomize to patch an existing deployment configuration. While Helm excels at packaging and distribution, Kustomize excels at configuration modification. Mastering both ensures you can install and configure essential cluster architecture components in a reproducible and scalable manner.
Using Helm and Kustomize to Install Cluster Components
Why it is Important In complex Kubernetes environments, managing raw YAML manifests manually is error-prone and difficult to scale. Helm and Kustomize are industry-standard tools that streamline this process. Helm acts as a package manager (like apt or yum) allowing for templating and versioning of applications, while Kustomize allows for configuration management via overlays, enabling you to patch manifests for different environments (dev, test, prod) without duplicating the base code.
What is it? Helm uses a packaging format called Charts. A Chart is a collection of files that describe a related set of Kubernetes resources. It separates configuration (values.yaml) from logic (templates). Kustomize is a tool built directly into kubectl that lets you customize raw, template-free YAML files for multiple purposes, leaving the original YAML untouched and usable as is.
How it Works Helm Workflow: 1. Repo: Add a chart repository using helm repo add. 2. Search: Find the package using helm search repo. 3. Install: Deploy the chart using helm install [release-name] [chart] [flags].
Kustomize Workflow: 1. Base: You have a directory with base YAMLs. 2. Kustomization: You create a kustomization.yaml file that references resources and defines patches (e.g., changing image tags or replica counts). 3. Apply: You deploy using kubectl apply -k [directory].
How to Answer Questions in the CKA Exam You may be asked to install a specific tool (like a monitoring agent or ingress controller) using Helm, or organize resources using Kustomize.
Example Helm Task: "Install the chart internal/apache with release name web-server in namespace web." Answer: 1. helm repo update (Good practice to ensure you see the chart). 2. helm install web-server internal/apache --namespace web --create-namespace.
Example Kustomize Task: "Apply the configuration located in /opt/manifests/app." Answer: 1. Verify the directory contains a kustomization.yaml file. 2. Run kubectl apply -k /opt/manifests/app.
Exam Tips: Answering Questions on Use Helm and Kustomize 1. Don't memorize URLs: The exam question will provide the specific Helm repository URL you need to add. Copy and paste it exactly. 2. Watch the Namespace: Helm v3 does not create namespaces by default. If the question asks to install into a specific namespace, verify if it exists. If not, append --create-namespace to your install command. 3. The -k Flag: Muscle memory often leads to typing kubectl apply -f. For Kustomize, you must use kubectl apply -k. 4. Idempotency:helm upgrade --install is a useful command if you aren't sure if a release already exists, though helm install is usually sufficient for a clean exam environment. 5. Verification: After running the helm or kustomize command, always run kubectl get pods -n [namespace] to ensure the components were actually created and are running.