JSON6902 patches should allow matching on group when version is not specified

[BenTheElder]

What would you like to be added:

the internal patch runtime should handle group / version matching so that GK can be specified without full GVK (Group, Version, Kind).

basically we want to allow not specfiying V (version) since versions are often largely the same but group and kind key totally different objects and we probably don't want patches applied to all objects.

Why is this needed:

To avoid surprising behavior when version is left unspecified in JSON6902 patches

/assign

[jiatongw]

Hi @BenTheElder, I have an idea.
Generally, a patch would be like this:

kubeadmConfigPatchesJson6902:
- group: kubeadm.k8s.io
  version: v1beta2
  kind: ClusterConfiguration

If the version field is empty, then we could get the kubeadm config file and read the version there. Then I could add the version field to the patch - I mean, programmatically. Then we could merge the patch to kubeadm config without any surprise. WDYT?

[jiatongw]

This is only for Kubeadm patch. For others, e.g. containerd patch, I have to dig more, or maybe this approach could also work

[BenTheElder]

We should not take this approach, because we also need to patch other component configs (kube-proxy, kubelet...)

We should fix how the match considers the group / version to be matching, the merge patches already support this correctly.

[BenTheElder]

"kubeadm config" is a bit of a misnomer and should probably get renamed, those patches patch the data that is supplied to kubeadm currently, which is more than just kubeadm's config object(s).

[jiatongw]

Your are right. I just focused on kubeadm configs. Let me do more research. Meanwhile, if you have better idea, please at me as well. I am happy to work on this

[BenTheElder]

re: renaming #2023