flag --port=0 to kube-controller-manager and kube-scheduler manifests to disable insecure serving. Without this flag the components by default serve (e.g. /metrics) insecurely on the default node interface (controlled by --address). Users that wish to override this behavior and enable insecure serving can pass a custom --port=X via kubeadm's "extraArgs" mechanic for these components. ([#92720](https://github.com/kubernetes/kubernetes/pull/92720), [@neolit123](https://github.com/neolit123)) [SIG Cluster...

flag --port=0 to kube-controller-manager and kube-scheduler manifests to disable insecure serving. Without this flag the components by default serve (e.g. /metrics) insecurely on the default node interface (controlled by --address). Users that wish to override this behavior and enable insecure serving can pass a custom --port=X via kubeadm's "extraArgs" mechanic for these components. ([#92720](https://github.com/kubernetes/kubernetes/pull/92720), [@neolit123](https://github.com/neolit123)) [SIG Cluster...

- Kubeadm: remove the `--port` flag from the manifest for the kube-scheduler since the flag has been a NO-OP since 1.23 and insecure serving was removed for the component. ([#105034](https://github.com/kubernetes/kubernetes/pull/105034), [@pacoxu](https://github.com/pacoxu))...

MUST read this before you upgrade)

- Stopped accepting component configuration for `kube-proxy` and `kubelet` during `kubeadm upgrade plan --config`. This was a legacy behavior that was not well supported for upgrades and could be used only at the plan stage to determine if the configuration for these components stored in the cluster needs manual version migration. In the future, `kubeadm` will attempt alternative component config migration approaches. ([#120788](https://github.com/kube...

- Kubeadm: Set the `seccompProfile` to `runtime/default` in the `PodSecurityContext` of the control-plane components that run as static Pods. ([#100234](https://github.com/kub...

- Component-base: make the validation logic about LeaderElectionConfiguration consistent between component-base and client-go ([#111758](https://github.com/kubernetes/kubernetes/pull/111758), [@SataQiu](https://github.com/SataQiu)) [SIG API Machinery and Scheduling]

### **Instrumentation**
#### Core Metrics API
* [alpha] Introduces a lightweight monitoring component for serving the core resource metrics API used by the Horizontal Pod Autoscaler and other components ([kubernetes/features#271](https://github.com/kubernetes/enhancements/issues/271))


### **Internationalization**

  It is possible that this will cause problems with some third-party components
  that improperly depended on those rules. If this affects you, you can run
  `kubelet` with `--feature-gates=IPTablesOwnershipCleanup=false`, but a bug should also be filed against the third-party component. ([#114472](https://github.com/kubernetes/kubernetes/pull/114472), [@danwinship](https://github.com/danwinship))

- Component owner can configure the allowlist of metric label with flag '--allow-metric-labels'. ([#99385](https://github.com/kubernetes/kubernetes/pull/99385), [@YoyinZyc](https://github.com/YoyinZyc)) [SIG API Machinery, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation and Release]

- Added to `MutableFeatureGate` the ability to override the default setting of feature gates, to allow default-enabling a feature on a component-by-component basis instead of for all affected components simultaneously. ([#122647](https://github.com/kubernetes/kubernetes/pull/122647), [@benluddy](https://github.com/benluddy))