- Kube-apiserver: Made the subresources `pods/exec`, `pods/attach`, and `pods/portforward` require `create` permission for both SPDY and Websocket API requests. Previously, SPDY requests required `create` permission, but Websocket requests only required `get` permission. This change is gated by the `AuthorizePodWebsocketUpgradeCreatePermission`...

- Enabled feature gates for PortForward (kubectl port-forward) over WebSockets by default (beta).
   - Server-side feature gate: PortForwardWebsocket
   - Client-side (kubectl) feature gate: PORT_FORWARD_WEBSOCKETS environment variable

- `kubectl run` can set a service account name in the generated pod
  spec with the `--serviceaccount` flag.

- `kubectl proxy` now correctly handles the `exec`, `attach`, and
  `portforward` commands.  You must pass `--disable-filter` to the command to allow these commands.

- Added `cronjobs.batch` to "all", so that `kubectl get all` returns them.

* The --long-running-request-regexp flag to kube-apiserver is deprecated and will be removed in a future release. Long-running requests are now detected based on specific verbs (watch, proxy) or subresources (proxy, portforward, log, exec, attach). ([#38119](https://github.com/kubernetes/kubernetes/pull/38119), [@liggitt](https://github.com/liggitt))

- Reverted the previous fix for portforward cleanup because it introduced a kubelet regression which can lead into segmentation faults. ([#102587](https://github.com/kubernetes/kubernetes/pull/102587), [@saschagrunert](https://github.com/saschagrunert)) [SIG API Machinery and Node]

## Changelog since v1.18.19

## Changes by Kind

### Bug or Regression

- Reverted the previous fix for portforward cleanup because it introduced a kubelet regression which can lead into segmentation faults. ([#102838](https://github.com/kubernetes/kubernetes/pull/102838), [@saschagrunert](https://github.com/saschagrunert)) [SIG API Machinery and Node]

- Fix: using NVMe AWS EBS volumes partitions. ([#100500](https://github.com/kubernetes/kubernetes/pull/100500), [@jsafrane](https://github.com/jsafrane))
- Fixed 'kubelet' runtime panic for timed-out portforward streams. ([#102489](https://github.com/kubernetes/kubernetes/pull/102489), [@saschagrunert](https://github.com/saschagrunert))

- Reverted the previous fix for portforward cleanup because it introduced a kubelet regression which can lead into segmentation faults. ([#102588](https://github.com/kubernetes/kubernetes/pull/102588), [@saschagrunert](https://github.com/saschagrunert)) [SIG API Machinery and Node]

* Exec and portforward actions over SPDY now properly handle redirects sent by the Kubelet ([#44451](https://github.com/kubernetes/kubernetes/pull/44451), [@ncdc](https://github.com/ncdc))

- Fixes a 1.30+ regression in connection stability for exec / attach / portforward requests initiated using a websocket client ([#130253](https://github.com/kubernetes/kubernetes/pull/130253), [@fuweid](https://github.com/fuweid)) [SIG API Machinery, CLI and Testing]