Use of Helm on Kubernetes with Charts

Configuring known apps using the Helm package manager.

Applications are complex collections of code and configuration that have a lot of nuance to how they are installed. Like all open source software, they can be installed from source code, but most of the time users want to install something simply and consistently. That’s why package managers exist in nearly every operating system, which manages the installation process.

Similarly, Kubernetes depends on package management to simplify the installation process. In this article, we’ll be using the Helm package manager and its concept of stable charts to create a small application.

What is Helm package manager?

Helm is a package manager for applications to be deployed to and run on Kubernetes. It is maintained by the Cloud Native Computing Foundation (CNCF) with collaboration with the largest companies using Kubernetes. Helm can be used as a command-line utility, which I cover how to use here.

What are Helm Charts?

We want to be able to repeatably install applications, but also to customize them to our environment. That’s where Helm Charts comes into play. Helm coordinates the deployment of applications using standardized templates called Charts. Charts are used to define, install, and upgrade your applications at any level of complexity.

A Chart is a Helm package. It contains all of the resource definitions necessary to run an application, tool, or service inside of a Kubernetes cluster. Think of it like the Kubernetes equivalent of a Homebrew formula, an Apt dpkg, or a Yum RPM file.

Using Helm

Charts are quick to create, and I find them straightforward to maintain. If you have one that is accessible from a public version control site, you can publish it to the stable repository to give it greater visibility. In order for a Chart to be added to stable, it must meet a number of technical requirements. In the end, if it is considered properly maintained by the Helm maintain, it can then be published to Helm Hub.

Helm is a powerful package manager that makes installing and uninstalling applications on top of Kubernetes as simple as a single command. Charts add to the experience by giving us curated and tested templates to install applications with our unique customizations.

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