cross-posted from: https://lemmy.run/post/10206

Creating a Helm Chart for Kubernetes

In this tutorial, we will learn how to create a Helm chart for deploying applications on Kubernetes. Helm is a package manager for Kubernetes that simplifies the deployment and management of applications. By using Helm charts, you can define and version your application deployments as reusable templates.

Prerequisites

Before we begin, make sure you have the following prerequisites installed:

• Helm: Follow the official Helm documentation for installation instructions.

Step 1: Initialize a Helm Chart

To start creating a Helm chart, open a terminal and navigate to the directory where you want to create your chart. Then, run the following command:

helm create my-chart

This will create a new directory named my-chart with the basic structure of a Helm chart.

Step 2: Customize the Chart

Inside the my-chart directory, you will find several files and directories. The most important ones are:

• Chart.yaml: This file contains metadata about the chart, such as its name, version, and dependencies.
• values.yaml: This file defines the default values for the configuration options used in the chart.
• templates/: This directory contains the template files for deploying Kubernetes resources.

You can customize the chart by modifying these files and adding new ones as needed. For example, you can update the Chart.yaml file with your desired metadata and edit the values.yaml file to set default configuration values.

Step 3: Define Kubernetes Resources

To deploy your application on Kubernetes, you need to define the necessary Kubernetes resources in the templates/ directory. Helm uses the Go template language to generate Kubernetes manifests from these templates.

For example, you can create a deployment.yaml template to define a Kubernetes Deployment:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .Release.Name }}-deployment
spec:
  replicas: {{ .Values.replicaCount }}
  template:
    metadata:
      labels:
        app: {{ .Release.Name }}
    spec:
      containers:
        - name: {{ .Release.Name }}
          image: {{ .Values.image.repository }}:{{ .Values.image.tag }}
          ports:
            - containerPort: {{ .Values.containerPort }}

This template uses the values defined in values.yaml to customize the Deployment's name, replica count, image, and container port.

Step 4: Package and Install the Chart

Once you have defined your Helm chart and customized the templates, you can package and install it on a Kubernetes cluster. To package the chart, run the following command:

helm package my-chart

This will create a .tgz file containing the packaged chart.

To install the chart on a Kubernetes cluster, use the following command:

helm install my-release my-chart-0.1.0.tgz

Replace my-release with the desired release name and my-chart-0.1.0.tgz with the name of your packaged chart.

Conclusion

Congratulations! You have learned how to create a Helm chart for deploying applications on Kubernetes. By leveraging Helm's package management capabilities, you can simplify the deployment and management of your Kubernetes-based applications.

Feel free to explore the Helm documentation for more advanced features and best practices.

Happy charting!