Moved client and kubeconfig related code to webhook/config;
Moved the rule matcher to webhook/rules;
Left TODOs saying we are going to move some other common utilities;
Other code is moved to webhook/validation.
Automatic merge from submit-queue (batch tested with PRs 54331, 54655, 54320, 54639, 54288). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Ability to do object count quota for all namespaced resources
**What this PR does / why we need it**:
- Defines syntax for generic object count quota `count/<resource>.<group>`
- Migrates existing objects to support new syntax with old syntax
- Adds support to quota all standard namespace resources
- Updates the controller to do discovery and replenishment on those resources
- Updates unit tests
- Tweaks admission configuration around quota
- Add e2e test for replicasets (demonstrate dynamic generic counting)
```
$ kubectl create quota test --hard=count/deployments.extensions=2,count/replicasets.extensions=4,count/pods=3,count/secrets=4
resourcequota "test" created
$ kubectl run nginx --image=nginx --replicas=2
$ kubectl describe quota
Name: test
Namespace: default
Resource Used Hard
-------- ---- ----
count/deployments.extensions 1 2
count/pods 2 3
count/replicasets.extensions 1 4
count/secrets 1 4
```
**Special notes for your reviewer**:
- simple object count quotas no longer require writing code
- deferring support for custom resources pending investigation about how to share caches with garbage collector. in addition, i would like to see how this integrates with downstream quota usage in openshift.
**Release note**:
```release-note
Object count quotas supported on all standard resources using `count/<resource>.<group>` syntax
```
Handle failure cases on startup gracefully to avoid causing cascading
errors and poor initialization in other components. Initial errors from
config load cause the initializer to pause and hold requests. Return
typed errors to better communicate failures to clients.
Add code to handle two specific cases - admin wants to bypass
initialization defaulting, and mirror pods (which want to bypass
initialization because the kubelet owns their lifecycle).
Dr. Stefan Schimanski