Automatic merge from submit-queue (batch tested with PRs 40544, 44338, 45225)

Use ObjectGetter Interface instead of clientset.Interface for leaderelection pkg

**What this PR does / why we need it**:
We plan to reuse leaderelection pkg to add leader election function to federation controller manager, but the current implementation uses kubernetes clientset.Interface and federation clientset does not satisfy all the interface methods. It would be better if the leaderelection package use rest.Interface which is also supported by federation clientset.
This pr is to refactor leaderelection pkg to use rest.Interface instead of clientset.Interface

**Special notes for your reviewer**:
This is a sub-task of bigger work to add leader election to federation controller manager as documented in #44283

**Release note**:
```
NONE
```

Automatic merge from submit-queue

Fixes broken link in PodSpec

The PodSpec reference to NodeSelector misses
the `.md` extension in the file.



**What this PR does / why we need it**:

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #

**Special notes for your reviewer**:

**Release note**:

```release-note
```

Automatic merge from submit-queue (batch tested with PRs 45227, 43003, 45231)

kubeadm: move preflight kubelet check

**What this PR does / why we need it**: If you passed the `--skip-preflight-checks` to kubeadm, it would still try to start up the kubelet, which is part of preflight checks. This was causing issues for test-cmds. Now, passing `--skip-preflight-checks` will skip over the kubelet check. 

**Special notes for your reviewer**: /cc @luxas @deads2k 

**Release note**:
```release-note
NONE
```

Automatic merge from submit-queue (batch tested with PRs 45227, 43003, 45231)

separate discovery from the apiserver

This decouples the API discovery handlers from the core API server code.  It separates the code into a new package and clarifies interfaces with existing TPR code.

@kubernetes/sig-api-machinery-pr-reviews

Automatic merge from submit-queue

Fix hollow proxy to watch services and endpoints

Ref #34727

Automatic merge from submit-queue (batch tested with PRs 45100, 45152, 42513, 44796, 45222)

apiserver: split endpoint tests from client-go

Use the example apigroup and create its own scheme.

Fixes https://github.com/kubernetes/kubernetes/issues/45209.

Automatic merge from submit-queue (batch tested with PRs 45100, 45152, 42513, 44796, 45222)

add subresource support to kube auth can-i

Eg:
    kubectl auth can-i get pods --sub-resource=log

**Release note**:

```release-note
```

Automatic merge from submit-queue (batch tested with PRs 45100, 45152, 42513, 44796, 45222)

[Federation] Generate the secret name in kubefed join.

Addresses part of #42324. A follow-up PR will address annotating Federation resources.

```release-note
Remove the `--secret-name` flag from `kubefed join`, instead generating the secret name arbitrarily.
```

Automatic merge from submit-queue (batch tested with PRs 45100, 45152, 42513, 44796, 45222)

Added InterPodAffinity unit test case with Namespace.

**What this PR does / why we need it**:
Added InterPodAffinity unit test case with Namespace: unit test case for #45098

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes # N/A

**Release note**:

```release-note-none
```

Automatic merge from submit-queue (batch tested with PRs 45100, 45152, 42513, 44796, 45222)

node-controller: deflake TestUpdateNodeWithMultiplePods

Automatic merge from submit-queue

Removed duplicated 'default' in kubelet's help message

```release-note
None
```

 The PodSpec reference to NodeSelector misses
 the .md extension in the file.

Revert test_owners.csv after bad rebase

Use absolute time and increase grace duration to 500ms for tests under load.

Eg:
    kubectl auth can-i get pods --subresource=log

Automatic merge from submit-queue

Remove GetClientsetForCluster()

The newClusterClientset() has insteaded of GetClientsetForCluster(),
and GetClientsetForCluster() run wrong. Let's remove it.

Automatic merge from submit-queue

Use munged semantic version for side-loaded docker tag

**What this PR does / why we need it**: rather than using the md5sum of the dockerized binary for each side-loaded docker image, use the semantic version (with `+`s replaced with `_`s) for the side-loaded docker images.

The use of the md5sum for the docker tag dates to #6326 2 years ago. I'm not sure why that was chosen, short of it being fairly unique.

My main motivation for changing this is that it makes building the docker images using Bazel's docker rules easier, since the semantic version doesn't depend on the build output.

An added benefit is that the list of images on a running kubernetes cluster is also more straightfoward; rather than a list of opaque, meaningless hexadecimal strings, you get something that indicates the provenance of the image. It'd also be clearer that all of the images came from the same build.

I was able to start a cluster with this change on GCE using both `make quick-release` and `make bazel-release`.

Note that this change has no effect on the tag that's pushed to gcr.io during releases; that's still controlled via `KUBE_IMAGE_DOCKER_TAG`, though we may want to merge this functionality at some point.

@kubernetes/sig-node-pr-reviews is there any reason to stick with using the md5sum strategy? @dchen1107 do you remember why we went with md5sums originally?
cc @spxtr @mikedanese 

**Release note**:

```release-note
```

Automatic merge from submit-queue (batch tested with PRs 45077, 45180, 34727, 45079, 45177)

Allow specifying cluster signing ca/key

**What this PR does / why we need it**:

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #

**Special notes for your reviewer**:

**Release note**:

```release-note
```

Automatic merge from submit-queue (batch tested with PRs 45077, 45180, 34727, 45079, 45177)

Move federated ingress e2e tests that don't pass to serial suite to avoid running it in presubmits.

This is due to a bug described here: https://github.com/kubernetes/ingress/issues/645. 

Federated Ingress e2es fail when there is a high load which is pretty common in the presubmit environment when the PR activity is high. So we are disabling these tests to unblock federation presubmits.

**Release note**:
```release-note
NONE
```

/assign @csbell 

cc @kubernetes/sig-federation-pr-reviews @nicksardo

Automatic merge from submit-queue (batch tested with PRs 45077, 45180, 34727, 45079, 45177)

Refactor kube-proxy configuration

This is a proof of concept refactoring of the configuration and startup of kube-proxy. Most flags have been removed and replaced by a single config file, specified by `--config`. This is in regards to the component configuration improvement suggestions listed in #32215.

Also during this effort, I discovered that Hyperkube is roughly reimplementing portions of cobra, and that the current cobra command definitions are solely used to generated docs and man pages. I would like to move the individual commands as well as Hyperkube to using cobra, but that is a separate issue and discussion.

cc @mikedanese @liggitt @deads2k @eparis @sttts @smarterclayton @dgoodwin @timothysc

Automatic merge from submit-queue (batch tested with PRs 45077, 45180, 34727, 45079, 45177)

Move k8s.io/metrics to staging/

This is to break the cyclic dependency in our code base: kubernetes depends on k8s.io/metrics, which depends on kubernetes/staging/client-go.

@DirectXMan12 i actually moved it to staging because we will need the flexibility to update metrics code directly to do many planned refactors, so the copy of metrics in kubernetes has to be the source of truth.

client-gen is not enabled for the code yet, we can enable it after you port your changes to client-gen.

`make generated_files` is enabled for metrics.

Automatic merge from submit-queue

examples/guestbook: remove not useful/inaccurate comments

The comments removed in this patch are either inaccurate or
does not serve any purpose as they're already applies as uncommented
in the tutorial and explained in the walkthrough text.

```release-note
NONE
```
Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

Automatic merge from submit-queue

Add e2e network policy tests.

**What this PR does / why we need it**:
Add set of e2e tests for Network Policy. This has succesfully run againast a deployment using Calico as the network policy provider.

Specifically, adds a new e2e test file (/test/e2e/network_policy.go) which tests TCP connectivity between pods with isolation.

See #25638 for PR that added NetworkPolicy resource.

This PR is a replacement for #27447 .

Automatic merge from submit-queue

Restructure unit tests for more cert/keys.

Just changing the unit tests so there is multiple cert/key pairs to be used.
No functional change, no new tests. Follow on PRs will make more use
of the multiple cert/key pairs.

Makes it useful in testing some scenarios with automatically
signing certificates

Automatic merge from submit-queue (batch tested with PRs 43884, 44712, 45124, 43883)

Node e2e: Remove CRI/non-CRI configs

This depends on https://github.com/kubernetes/test-infra/pull/2363

Automatic merge from submit-queue (batch tested with PRs 43884, 44712, 45124, 43883)

Increase pv test ns deletion timeout to the framework's default.

**What this PR does / why we need it**:
Namespace deletion occasionally exceeds the test's timeout of 3 minutes.  The test framework uses a default timeout of 5 minutes, so just making it match here.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #44790

**Special notes for your reviewer**:

**Release note**:

NONE

Automatic merge from submit-queue (batch tested with PRs 43884, 44712, 45124, 43883)

Increase Dashboard memory limits

**What this PR does / why we need it**: Increases memory requests and limits for Dashboard.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes https://github.com/kubernetes/dashboard/issues/1431

**Special notes for your reviewer**: Dashboard crashes on large clusters, this change should fix that problem.

**Release note**:

```release-note
Increase Dashboard's memory requests and limits
```

Automatic merge from submit-queue

Remove DockerManager from kubelet

This commit deletes code in dockertools that is only used by
DockerManager. A follow-up change will rename and clean up the rest of
the files in this package.

The commit also sets EnableCRI to true if the container runtime is not
rkt. A follow-up change will remove the flag/field and all references to
it.

Add support for configuring kube-proxy via a config file instead of
command line flags.

Automatic merge from submit-queue

adds Ubuntu node e2e test

**What this PR does / why we need it**:

Add node e2e test for Ubuntu image.

**Special notes for your reviewer**:

**Release note**:

```NONE```

Automatic merge from submit-queue (batch tested with PRs 44062, 45165)

Run SSH e2e test only if SSH keys are present

**What this PR does / why we need it**:

Not all CI systems support ssh keys to be present on the node. This
supports the case where "local" provider is being used when running
e2e test, but the environment does not have a SSH key.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```