- Made `kubectl-convert` binary linking static (also affects the deb and rpm packages). ([#114228](https://github.com/kubernetes/kubernetes/pull/114228), [@saschagrunert](https://github.com/saschagrunert))
- Migrated controller helper functions to use contextual logging. ([#115049](https://github.com/kubernetes/kubernetes/pull/115049), [@fatsheep9146](https://github.com/fatsheep9146))

* Increase allowed lag for ssh key sync loop in tunneler to allow for one failure ([#60068](https://github.com/kubernetes/kubernetes/pull/60068), [@wojtek-t](https://github.com/wojtek-t))

### Other (Cleanup or Flake)

- Kube-apiserver: sets an upper-bound on the lifetime of idle keep-alive connections and time to read the headers of incoming requests ([#103958](https://github.com/kubernetes/kubernetes/pull/103958), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Node]

* Fix charms leaving services running after remove-unit ([#48446](https://github.com/kubernetes/kubernetes/pull/48446), [@Cynerva](https://github.com/Cynerva))
* Added helper funcs to schedulercache.Resource. ([#46926](https://github.com/kubernetes/kubernetes/pull/46926), [@k82cn](https://github.com/k82cn))

- Added new k8s.io/component-helpers repository providing shared helper code for (core) components. ([#92507](https://github.com/kubernetes/kubernetes/pull/92507), [@ingvagabund](https://github.com/ingvagabund)) [SIG Apps, Node, Release and Scheduling]

up flag handling in component-base/logs: that package no longer adds flags to the global flag sets. Commands which want the klog and `--log-flush-frequency` flags must explicitly call `logs.AddFlags`; the new `cli.Run` does that for commands. That helper function also covers flag normalization and printing of usage and errors in a consistent way (print usage text first if parsing failed, then the error). ([#105076](https://github.com/kubernetes/kubernetes/pull/105076), [@pohly](https://github.com/pohly))...

- Fix an issue with toleration merging & whitelist checking in the PodTolerationRestriction admission controller. ([#81732](https://github.com/kubernetes/kubernetes/pull/81732), [@tallclair](https://github.com/tallclair))
- Add a helper function to decode scheduler plugin args. ([#80696](https://github.com/kubernetes/kubernetes/pull/80696), [@hex108](https://github.com/hex108))

* The init-container (pod.beta.kubernetes.io/init-containers) annotations used to accept capitalized field names that could be accidentally generated by the k8s.io/kubernetes/pkg/api package. Using an upper case field name will now return an error and all users should use the versioned API types from `pkg/api/v1` when serializing from Golang.

## Action Required Before Upgrading

### Other (Cleanup or Flake)

- Kube-apiserver: sets an upper-bound on the lifetime of idle keep-alive connections and time to read the headers of incoming requests ([#103958](https://github.com/kubernetes/kubernetes/pull/103958), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Node]

- New feature gate, ServiceIPStaticSubrange, to enable the new strategy in the Service IP allocators, so the IP range is subdivided and dynamic allocated ClusterIP addresses for Services are allocated preferently from the upper range. ([#106792](https://github.com/kubernetes/kubernetes/pull/106792), [@aojea](https://github.com/aojea))