Why CRD definition is required

General Discussions
1

Hi

Sorry I may be asking a dump question.

Since resources are stored in etcd in serialized form (json or protobuf), and since serialization/de-serialization done by the client/scheme, what is the real use of this CRD definition inside apiserver?.

One use I can think of is discovery, it may be giving single endpoints for all resources of same kind.

other wise another use is code-generator(controller, client etc), which is not a runtime use.

What is the real use of CRD definition inside apiserver?, where it helps?

-Nobin

2

It allows schematic validation, so you don’t pass a string where it expects an int. And discovery. And openapi docs. And more and more metadata and logic, over time.

3

Another search, on schematic validation showed up one good link, little deep in code.