API Access

Kubernetes has a powerful REST-based API. The entire architecture is API-driven. Knowing where to find resource endpoints and understanding how the API changes between versions can be important to ongoing administrative tasks, as there is much ongoing change and growth. Starting with v1.16 deprecated objects are no longer honored by the API server.

As we learned in the Kubernetes Architecture chapter, the main agent for communication between cluster agents and from outside the cluster is the kube-apiserver. A curl query to the agent will expose the current API groups. Groups may have multiple versions, which evolve independently of other groups, and follow a domain-name format with several names reserved, such as single-word domains, the empty group, and any name ending in .k8s.io.