Automatic merge from submit-queue. 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>.
Add stub device plugin for conformance e2e test
**What this PR does / why we need it**:
Add stub device plugin for conformance e2e test
- extend [device_plugin_stub](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/cm/deviceplugin/device_plugin_stub.go) to support e2e test
- add test suite with this device-plugin-stub
- simulate more use cases by deploying some pods to request these resources
**Which issue this PR fixes**:
fixes#52861
**Special notes for your reviewer**:
@vishh @jiayingz PTAL.
**Release note**:
```release-note
None
```
Automatic merge from submit-queue. 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>.
[Alpha: DynamicKubeletConfig] Double check before setKubeletConfiguration
**What this PR does / why we need it**:
Double check the `newCfg` is not equal to the `oldCfg` before we call `setKubeletConfiguration(newCfg)` in `tempSetCurrentKubeletConfig()`.
**Which issue(s) this PR fixes**:
Fixes https://github.com/kubernetes/kubernetes/issues/57701
**Special notes for your reviewer**:
/area kubelet
/sig node
/assign @mtaufen
/cc @vishh @jiayingz @derekwaynecarr @dchen1107 @liggitt
PTAL, Thanks!
**Release note**:
```release-note
NONE
```
Command line flag API remains the same. This allows ComponentConfig
structures (e.g. KubeletConfiguration) to express the map structure
behind feature gates in a natural way when written as JSON or YAML.
For example:
KubeletConfiguration Before:
```
apiVersion: kubeletconfig/v1alpha1
kind: KubeletConfiguration
featureGates: "DynamicKubeletConfig=true,Accelerators=true"
```
KubeletConfiguration After:
```
apiVersion: kubeletconfig/v1alpha1
kind: KubeletConfiguration
featureGates:
DynamicKubeletConfig: true
Accelerators: true
```
Rather than just changing the config once to see if dynamic kubelet
config at-least-sort-of-works, this extends the test to check that the
Kubelet reports the expected Node condition and the expected configuration
values after several possible state transitions.
Additionally, this adds a stress test that changes the configuration 100
times. It is possible for resource leaks across Kubelet restarts to
eventually prevent the Kubelet from restarting. For example, this test
revealed that cAdvisor's leaking journalctl processes (see:
https://github.com/google/cadvisor/issues/1725) could break dynamic
kubelet config. This test will help reveal these problems earlier.
This commit also makes better use of const strings and fixes a few bugs
that the new testing turned up.
Related issue: #50217
This reverts commit f4afdecef8, reversing
changes made to e633a1604f.
This also fixes a bug where Kubemark was still using the core api scheme
to manipulate the Kubelet's types, which was the cause of the initial
revert.
