Chart values and customization in Kubernetes - Mini Project: Build & Apply

Chart values and customization

📖 Scenario: You are deploying a simple web application using Helm charts on Kubernetes. You want to customize the deployment by changing the number of replicas and the container image version using the chart's values.yaml file.

🎯 Goal: Learn how to set up a values.yaml file with specific values and customize a Helm chart deployment by overriding default values.

📋 What You'll Learn

Create a values.yaml file with specific values

Add a variable for the number of replicas

Use the variable in the deployment template

Print the final rendered Kubernetes deployment manifest

💡 Why This Matters

🌍 Real World

Helm charts are widely used to package and deploy applications on Kubernetes clusters. Customizing chart values allows teams to deploy the same application with different settings easily.

💼 Career

Understanding how to customize Helm charts is essential for Kubernetes administrators and DevOps engineers to manage scalable and configurable deployments.

1

Create the initial values.yaml file

Create a values.yaml file with the following exact content:
replicaCount: 2
image:
repository: nginx
tag: 1.19.0

Kubernetes

# Create a values.yaml file with replicaCount 2 and image repository nginx with tag 1.19.0
# Your code here

Need a hint?

The values.yaml file defines default values for your Helm chart. Use proper indentation for nested keys.

2

Add a variable for replicas in the deployment template

In the deployment template file deployment.yaml, add the line replicas: {{ .Values.replicaCount }} under the spec: section to use the replicaCount value from values.yaml.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  # Add replicas line here
  template:
    spec:
      containers:
      - name: nginx
        image: nginx:1.19.0
# Your code here

Need a hint?

Use Helm template syntax {{ .Values.replicaCount }} to access the value from values.yaml.

3

Use image repository and tag variables in the container spec

Modify the container image line in deployment.yaml to use the repository and tag from values.yaml with this exact syntax:
image: {{ .Values.image.repository }}:{{ .Values.image.tag }}

Kubernetes

replicaCount: 2
image:
  repository: nginx
  tag: 1.19.0
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: {{ .Values.replicaCount }}
  template:
    spec:
      containers:
      - name: nginx
        # Update image line here
# Your code here

Need a hint?

Use Helm template variables to dynamically set the container image from values.yaml.

4

Render and print the final Kubernetes deployment manifest

Run the Helm template command to render the deployment manifest using the values.yaml file and print the output exactly as shown:
helm template my-nginx . -f values.yaml

Kubernetes

# Run the Helm template command below
# Your code here

Need a hint?

Use the helm template command with the -f values.yaml option to apply your custom values and see the final manifest.