In this chapter, we covered three major topics: working with the Kubernetes API, extending the Kubernetes API, and writing Kubernetes plugins. The Kubernetes API supports the OpenAPI spec and is a great example of REST API design that follows all current best practices. It is very consistent, well organized, and well documented, yet it is a big API and is not easy to understand. You can access the API directly via REST over HTTP, using client libraries including the official Python client, and even by invoking Kubectl.

Extending the Kubernetes API involves defining your own custom resources and optionally extending the API server itself via API aggregation. Custom resources are most effective when you combine them with additional custom plugins or controllers when you query and update them externally.

Plugins and webhooks are the foundation of Kubernetes design. Kubernetes...