- The `--leader-elect*` CLI args are now honored in scheduler. ([#105915](https://github.com/kubernetes/kubernetes/pull/105915), [@Huang-Wei](https://github.com/Huang-Wei))

- Added a path `/header?key=` to `agnhost netexec` allowing one to view what the header value is of the incoming request.

  Ex:
  ```
  $ curl -H "X-Forwarded-For: something" 172.17.0.2:8080/header?key=X-Forwarded-For
  something
  ```

* Fixes CVE-2019-11250: client-go header logging (at verbosity levels >= 7) now masks `Authorization` header contents ([#81330](https://github.com/kubernetes/kubernetes/pull/81330), [@tedyu](https://github.com/tedyu))

* Reduce time needed to attach Azure disks ([#40066](https://github.com/kubernetes/kubernetes/pull/40066), [@codablock](https://github.com/codablock))
* Fixes request header authenticator by presenting the request header client CA so that the front proxy will authenticate using its client certificate. ([#40301](https://github.com/kubernetes/kubernetes/pull/40301), [@deads2k](https://github.com/deads2k))

- Changed: default "Accept-Encoding" header removed from HTTP probes. See https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/#http-probes ([#96127](https://github.com/kubernetes/kubernetes/pull/96127), [@fonsecas72](https://github.com/fonsecas72)) [SIG Network and Node]

- Support more than 100 disk mounts on Windows (#105673, @andyzhangx) [SIG Storage and Windows]
- The --leader-elect* CLI args are now honored correctly in scheduler. (#106130, @Huang-Wei) [SIG Scheduling]
- The kube-proxy sync_proxy_rules_iptables_total metric now gives
  the correct number of rules, rather than being off by one.
  

### Other (Cleanup or Flake)

- Client-go header logging (at verbosity levels >= 9) now masks `Authorization` header contents ([#95316](https://github.com/kubernetes/kubernetes/pull/95316), [@sfowl](https://github.com/sfowl)) [SIG API Machinery]

## Dependencies

### Added
_Nothing has changed._

### Bug or Regression

- Client-go: fixes potential data races retrying requests using a custom io.Reader body; with this fix, only requests with no body or with string / []byte / runtime.Object bodies can be retried ([#113933](https://github.com/kubernetes/kubernetes/pull/113933), [@liggitt](https://github.com/liggitt)) [SIG API Machinery]

- Client-go: Optimized leaders renewing leases by updating leader lock optimistically without getting the record from the API server first. Also, a new metric `leader_election_slowpath_total` was added to allow users to monitor how many leader elections are updated non-optimistically.

* Add "deploy" abbrev for deployments to kubectl ([#24087](https://github.com/kubernetes/kubernetes/pull/24087), [@Frostman](https://github.com/Frostman))
* --no-header available now for custom-column ([#26696](https://github.com/kubernetes/kubernetes/pull/26696), [@gitfred](https://github.com/gitfred))



# v1.4.0-alpha.1