Managing Kubernetes

Chapter 13. Extending Kubernetes

Kubernetes has a rich API that provides much of the functionality that you might need to build and operate a distributed system. However, the API is purposefully generic, aimed at the 80% use cases. Taking advantage of the rich ecosystem of add-ons and extensions that exist for Kubernetes can add significant new functionality and enable new experiences for users of your cluster. You may even choose to implement your own custom add-ons and extensions that are suited to the particular needs of your company or environment.

Kubernetes Extension Points

There are a number of different ways to extend a Kubernetes cluster, and each offers a different set of capabilities and additional operational complexity. The following sections describe these various extension points in detail and provide insight into how they can extend the functionality of a cluster and into the additional operational requirements of these extensions.

The four types of extensibility are:

• Cluster daemons for automation

• Cluster assistants for extended functionality

• Extending the life cycle of the API server

• Adding more APIs

The truth, of course, about some of these classifications is that they are somewhat arbitrary, and there are different extensions that can combine multiple kinds of extensibility to provide additional functionality for a cluster. The categories described here are intended to help guide your discussion and planning for extending a Kubernetes cluster. They ...