- Fixed a race condition in kube-controller-manager and the scheduler, caused by
  a bug in the transforming informer during the Resync operation, 
  by making the transforming function idempotent. ([#124352](https://github.com/kubernetes/kubernetes/pull/124352), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery and Scheduling]

### SIG Auth

Work this cycle focused on graduating existing functions, and on making security functions more understandable for users.

	response, err = s.client.Do(request)
	c.Assert(err, nil)
	// assert the status code of the response.
	c.Assert(response.StatusCode, http.StatusOK)

	// constructing http request to delete the bucket.
	// making an attempt to delete an non-empty bucket.
	// expected to fail.
	request, err = newTestSignedRequest(http.MethodDelete, getDeleteBucketURL(s.endPoint, bucketName),
		0, nil, s.accessKey, s.secretKey, s.signer)

- Renames the timeout field for the DelegatingAuthenticationOptions to TokenRequestTimeout and set the timeout only for the token review client. Previously the timeout was also applied to watches making them reconnecting every 10 seconds. ([#101103](https://github.com/kubernetes/kubernetes/pull/101103), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery, Auth and Cloud Provider]

  startup/readiness/liveness probe capabilities. Lifecycle handlers configured
  with `scheme: HTTPS` that encounter errors indicating the endpoint is actually
  using HTTP fall back to making the request over HTTP for compatibility with
  previous releases. When this happens, a `LifecycleHTTPFallback` event is recorded
  in the namespace of the pod and a `kubelet_lifecycle_handler_http_fallbacks_total`

- Fixed a bug which the scheduler didn't correctly tell plugins Node deletion.

- Kubeadm: remove the `--port` flag from the manifest for the `kube-controller-manager` since the flag has...

With CSI the Kubernetes volume layer becomes truly extensible, allowing third party storage developers to write drivers making their storage systems available in Kubernetes without having to touch the core code.

CSI was first introduction as alpha in Kubernetes v1.9 and moved to beta in Kubernetes v1.10.

 $breakpoints: $grid-breakpoints) {\n  $max: map-get($breakpoints, $name);\n  @return if($max and $max > 0, $max - .02, null);\n}\n\n// Returns a blank string if smallest breakpoint, otherwise returns the name with a dash in front.\n// Useful for making responsive utilities.\n//\n//    >> breakpoint-infix(xs, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px, xxl: 1400px))\n//    \"\"  (Returns a blank string)\n//    >> breakpoint-infix(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px, xxl:...

* Fix for Pod stuck in ContainerCreating with error "Volume is not yet attached according to node". ([#50806](https://github.com/kubernetes/kubernetes/pull/50806), [@verult](https://github.com/verult))
* Fixed controller manager crash by making it tolerant to discovery errors.([#49767](https://github.com/kubernetes/kubernetes/pull/49767), [@deads2k](https://github.com/deads2k))