Chart templates and values.yaml in Kubernetes - Mini Project: Build & Apply

Create a Helm Chart with Templates and values.yaml

📖 Scenario: You are working as a DevOps engineer. Your team wants to deploy a simple web application using Helm charts on Kubernetes. You need to create the basic Helm chart files: a values.yaml file to hold configuration values and a template file to use those values.

🎯 Goal: Build a Helm chart with a values.yaml file containing application settings and a template file that uses these values to generate a Kubernetes Deployment manifest.

📋 What You'll Learn

Create a values.yaml file with specific keys and values

Create a template file deployment.yaml that uses values from values.yaml

Use Helm template syntax to insert values

Output the final rendered Deployment manifest

💡 Why This Matters

🌍 Real World

Helm charts are widely used to package, configure, and deploy applications on Kubernetes clusters in a repeatable way.

💼 Career

Understanding Helm charts and how to use <code>values.yaml</code> and templates is essential for DevOps engineers working with Kubernetes deployments.

1

Create the values.yaml file

Create a values.yaml file with these exact entries:
appName: myapp
replicaCount: 3
image:
repository: nginx
tag: stable

Kubernetes

# Create the values.yaml content below
# Your code here

Need a hint?

The values.yaml file holds configuration values in YAML format. Use indentation for nested keys like image.repository.

2

Create the deployment.yaml template

Create a Helm template file named deployment.yaml that starts with apiVersion: apps/v1 and kind: Deployment. Use the value .Values.appName for metadata.name and spec.replicas. Use .Values.image.repository and .Values.image.tag for the container image.

Kubernetes

appName: myapp
replicaCount: 3
image:
  repository: nginx
  tag: stable

# Create deployment.yaml template below
# Your code here

Need a hint?

Use double curly braces {{ }} to insert values from values.yaml in the template.

3

Render the Helm template

Write a command to render the Helm template using helm template with the current directory as the chart location.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .Values.appName }}
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      app: {{ .Values.appName }}
  template:
    metadata:
      labels:
        app: {{ .Values.appName }}
    spec:
      containers:
      - name: {{ .Values.appName }}
        image: {{ .Values.image.repository }}:{{ .Values.image.tag }}

# Write the helm template command below
# Your code here

Need a hint?

The helm template . command renders the templates in the current directory without installing them.

4

Display the rendered Deployment manifest

Run the helm template . command and print the output to show the rendered Kubernetes Deployment manifest.

Kubernetes

# Run the helm template command and print the output below
# Your code here

Need a hint?

Use Python's subprocess module to run the helm template . command and print the output.