Confusing doc on name of object of kind defined by CRD

[MikeSpreitzer]

This is a Bug Report

Problem:

I wondered what are the restrictions (if any) that Kubernetes imposes on the names of objects of a kind that gets defined by a CustomResourceDefinition. I am not talking about the name of the CRD itself. I tried to find this in the documentation, and couldn't. I asked on the sig-api-machinery channel on the Kubernetes Slack, and was referred to https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/#customresourcedefinitions . The text there says

The name of a CRD object must be a valid DNS subdomain name.

Since a CRD is itself an object, I thought this was clearly talking about the name of the CRD itself (I temporarily forgot that I know that the name of the CRD itself is constrained to be ${resouce}.${apiGroup}). But I was assured that this text is trying to talk about the objects whose kind is defined by the CRD.

Proposed Solution:

Update the cited doc to be clearer.

Page to Update:
https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources

[pranav-pandey0804]

/sig docs
/language en

[sftim]

/triage accepted
/wg api-expression

Since a CRD is itself an object, I thought this was clearly talking about the name of the CRD itself

Yes, that's right. Both I and @tengqm confirm this; I'm an emeritus tech lead for SIG Docs, and @tengqm is a current tech lead.

(I temporarily forgot that I know that the name of the CRD itself is constrained to be ${resouce}.${apiGroup}).

(sic)

Would be good to add that detail to the page.