Using Helm charts for Java application deployment on Kubernetes

02 Oct 2023

Kubernetes

In the world of containerization and orchestration, Kubernetes has gained immense popularity. It provides a platform for managing and scaling containerized applications. However, deploying complex applications can be time-consuming and error-prone. This is where Helm, the package manager for Kubernetes, comes into play.

Helm allows you to define, install, and manage applications in Kubernetes using “charts”. A Helm chart is a collection of files that describe the necessary resources and configuration for deploying an application. In this blog post, we will explore how to leverage Helm charts for deploying Java applications on Kubernetes.

Why use Helm for Java application deployment?

When it comes to deploying complex Java applications on Kubernetes, there are several benefits to using Helm:

Modularity and reusability: Helm charts provide a modular and reusable way to package and deploy Java applications on Kubernetes. You can create generic charts that can be customized for different environments and easily shared with others.
Configuration management: Helm allows you to separate your application code from its configuration using values files. This makes it easy to manage and update configurations for different environments without modifying the application code.
Versioning and rollbacks: With Helm, you can easily version your application deployments and roll back to a previous version if required. This makes it simple to manage multiple releases and handle potential issues during deployment.

Setting up Helm for Java application deployment

Before we dive into deploying Java applications using Helm, let’s set up Helm on our local machine and configure it to work with our Kubernetes cluster.

Install Helm: You can download and install Helm from the official Helm website. Choose the appropriate package for your operating system and follow the installation instructions.
Initialize Helm: Once Helm is installed, run the following command to initialize Helm and install Tiller, the server-side component of Helm, into your Kubernetes cluster:
```
helm init
```
This command will create a new namespace called “kube-system” and deploy Tiller into it. Tiller will manage the installation and deployment of Helm charts in your Kubernetes cluster.
Verify Helm installation: To verify that Helm and Tiller are correctly installed, run the following command:
```
helm version
```
This should display the version information for both the client-side and server-side components of Helm.

Deploying a Java application using a Helm chart

Now that we have Helm set up and configured, let’s deploy a Java application using a Helm chart. We assume that you have a basic Java application that you want to deploy on Kubernetes.

Create a Helm chart: Navigate to the root directory of your Java application and run the following command to create a new Helm chart:
```
helm create my-java-app
```
This will generate a basic Helm chart structure with various files and directories.
Update the chart files: Update the generated chart files according to your Java application’s requirements. Modify the values.yaml file to set the necessary configuration options such as image name, port, environment variables, etc. You can add additional Kubernetes resource definitions in the templates directory.
Package the chart: Once you have made the necessary changes to your Helm chart, run the following command to package it:
```
helm package my-java-app
```
This will create a gzipped tar archive of your Helm chart.
Deploy the chart: To deploy the chart to your Kubernetes cluster, use the following command:
```
helm install my-java-app my-java-app-1.0.0.tgz
```
Replace my-java-app-1.0.0.tgz with the actual name of your chart package.

And that’s it! Your Java application should now be deployed on your Kubernetes cluster using the Helm chart.

Conclusion

Helm charts provide a powerful and flexible way to deploy Java applications on Kubernetes. They enable modularity, reusability, configuration management, versioning, and rollbacks. By following the steps outlined in this blog post, you can easily leverage Helm charts to simplify the deployment of your Java applications on Kubernetes.

#Java #Kubernetes