- From now on, the HPA controller will return an error for the container resource metrics when the feature gate `HPAContainerMetrics` is disabled. As a result, HPA with a container resource metric performs no scale-down and performs only. ([#116043](https://github.com/kubernetes/kubernetes/pull/116043), [@sanposhiho](https://github.com/sanposhiho))

join` only did the discovery part and exited successfully without checking that the kubelet actually started properly and performed the TLS bootstrap correctly. Now, as kubeadm runs some post-join steps (for example, annotating the Node API object with the CRISocket), `kubeadm join` is now waiting for the kubelet to perform the TLS Bootstrap, and then uses that credential to perform further actions. This also improves the UX, as `kubeadm` will exit with a non-zero code if the kubelet isn't in a functional...

#### Go Client
* Add support for client-side spam filtering of events([#47367](https://github.com/kubernetes/kubernetes/pull/47367))

- Kubeadm: during join when a check is performed that a Node with the same name already exists in the cluster, make sure the NodeReady condition is properly validated ([#89602](https://github.com/kubernetes/kubernetes/pull/89602), [@kvaps](https://github.com/kvaps)) [SIG Cluster Lifecycle]

* Fix container hostPid settings when CRI is enabled. ([#44116](https://github.com/kubernetes/kubernetes/pull/44116), [@feiskyer](https://github.com/feiskyer))
* RBAC role and rolebinding auto-reconciliation is now performed only when the RBAC authorization mode is enabled. ([#43813](https://github.com/kubernetes/kubernetes/pull/43813), [@liggitt](https://github.com/liggitt))

- kubeadm: when adding new control plane nodes with `kubeamd join`, ensure that the etcd member addition is performed only if a given member URL does not already exist in the list of members. Similarly, on "kubeadm reset" only remove an etcd member if its ID exists. ([#127491](https://github.com/kubernetes/kubernetes/pull/127491), [@SataQiu](https://github.com/SataQiu))...

* Clean up old eclass code ([#71399](https://github.com/kubernetes/kubernetes/pull/71399), [@resouer](https://github.com/resouer))
* Fix a race condition in which kubeadm only waits for the kubelets kubeconfig file when it has performed the TLS bootstrap, but wasn't waiting for certificates to be present in the filesystem ([#72030](https://github.com/kubernetes/kubernetes/pull/72030), [@ereslibre](https://github.com/ereslibre))

    * 2. A cluster can be dualstack (i.e. Pods and nodes carry dualstack IPs) but does not need to support ingress on dualstack. In this case the cluster can perform egress using `PodIPs` (according to family and binding selection in user code) but will ingress will only be performed against the pod primary IP. This can be configured by supplying single entry to `--service-cluster-ip-range` flag.

- Graduated ServerSideFieldValidation to `beta`. Schema validation is performed server-side and requests will receive warnings for any invalid/unknown fields by default. ([#110178](https://github.com/kubernetes/kubernetes/pull/110178), [@kevindelgado](https://github.com/kevindelgado)) [SIG API Machinery, Architecture, Auth,...

  - true/strict - perform validation and error the request on any invalid fields in the ojbect. It will attempt to perform server-side validation if it is enabled on the apiserver, otherwise it will fall back to client-side validation.