Introduction to Kubernetes Helm Charts

In this post we are going to discuss a tool used with Kubernetes called Helm. Part of our multi-part Kubernetes Guide, this article will:

• Explore Helm charts
• Determine when and why to use Helm and Helm Charts
• Provide instructions for getting started

To explore other K8s topics, use the navigation menu on the right-hand side.

(This article is part of our Kubernetes Guide. Use the right-hand menu to navigate.)

What is Helm?

In simple terms, Helm is a package manager for Kubernetes. Helm is the K8s equivalent of yum or apt. Helm deploys charts, which you can think of as a packaged application. It is a collection of all your versioned, pre-configured application resources which can be deployed as one unit. You can then deploy another version of the chart with a different set of configuration.

Helm helps in three key ways:

• Improves productivity
• Reduces the complexity of deployments of microservices
• Enables the adaptation of cloud native applications

Why use Helm?

Writing and maintaining Kubernetes YAML manifests for all the required Kubernetes objects can be a time consuming and tedious task. For the simplest of deployments, you would need at least 3 YAML manifests with duplicated and hardcoded values. Helm simplifies this process and creates a single package that can be advertised to your cluster.

Helm is a client/server application and, until recently, has relied on Tiller (the helm server) to be deployed in your cluster. This gets installed when installing/initializing helm on your client machine. Tiller simply receives requests from the client and installs the package into your cluster. Helm can be easily compared to RPM of DEB packages in Linux, providing a convenient way for developers to package and ship an application to their end users to install.

Once you have Helm installed and configured (details below), you are able to install production-ready applications from software vendors, such as MongoDB, MySQL and others, into your Kubernetes cluster with one very simple helm install command. Additionally, removing installed applications in your cluster is as easy as installing them.