How to Create Helm Charts

Helm Charts simplify the process of deploying and managing applications on Kubernetes. By packaging K8s YAML files into a single chart, developers can easily define, install, and upgrade applications.

Prerequisites

• Basic understanding of Kubernetes
• Helm installed on your machine – follow our guide on installing Helm (Official site)
• Access to a Kubernetes cluster

Step-by-Step Guide to Creating a Helm Chart

Step 1: Create a New Helm Chart

First, create a new Helm chart using the command:

helm create mychart

This command generates a basic directory structure for the chart within a new directory named mychart.

Step 2: Understand the Chart Structure

The newly created chart contains the following:

• Chart.yaml: The main configuration file for the chart.
• values.yaml: Default configuration values.
• templates/: Contains the Kubernetes YAML templates.

Step 3: Customize the Values File

Edit the values.yaml file to set default values for your configurations. This file allows users to input variable data without altering templates.

Step 4: Write Kubernetes YAML Manifests

Navigate to the templates/ directory and add or edit the YAML files to describe your Kubernetes resources, such as Deployments and Services.

Step 5: Use Templates Effectively

Helm uses Go templates to customize YAML files. For example, use:

replicas: {{ .Values.replicas }}

This snippet pulls the replicas count from the values file.

Step 6: Install the Chart

Deploy your application using the following command:

helm install myapp ./mychart

This command installs the Helm chart to your Kubernetes cluster.

Step 7: Update or Upgrade Your Chart

To update an existing release, modify the chart or values and execute:

helm upgrade myapp ./mychart

This command applies the updates to your deployment.

Troubleshooting

• Ensure your cluster context is set correctly using kubectl config use-context.
• If installations fail, check output logs for any configuration errors.

Summary Checklist

• Create and explore a Helm chart structure.
• Customize values.yaml.
• Edit Kubernetes manifests in templates/.
• Use Helm commands to install and upgrade applications.
• Troubleshoot using logs and Helm’s template debugging tools.