- Kubeadm now respects user specified etcd versions in the ClusterConfiguration and properly uses them. If users do not want to stick to the version specified in the ClusterConfiguration, they should edit the kubeadm-config config map and delete it. ([#89588](https://github.com/kubernetes/kubernetes/pull/89588), [@rosti](https://github.com/rosti)) [SIG Cluster Lifecycle]...

- Kubeadm: avoided uploading a defaulted flag value "--authorization-mode=Node,RBAC" for the kube-apiserver in the ClusterConfiguration stored in the "kube-system/kubeadm-config" ConfigMap. "Node,RBAC" are already the kubeadm defaults for this flag, so this action is redundant. ([#123555](https://github.com/kubernetes/kubernetes/pull/123555), [@neolit123](https://github.com/neolit123))...

- Kubeadm: external etcd endpoints passed in the `ClusterConfiguration` that have Unicode characters are no longer IDNA encoded (converted to Punycode). They are now just URL encoded as per Go's implementation of RFC-3986, have duplicate "/" removed from the URL paths, and passed like that directly to the `kube-apiserver`...

* kubeadm: Control plane component configs are separated into ClusterConfiguration sub-structs. ([#70371](https://github.com/kubernetes/kubernetes/pull/70371), [@rosti](https://github.com/rosti))

- Kubeadm: during "upgrade apply/diff/node", in case the `ClusterConfiguration.imageRepository` stored in the "kubeadm-config" `ConfigMap` contains the legacy "k8s.gcr.io" repository, modify it to the new default "registry.k8s.io". Reflect the change in the in-cluster `ConfigMap` only during "upgrade apply". ([#11034...

- Kubeadm: fixed bug where v1beta3's ClusterConfiguration.APIServer.TimeoutForControlPlane is not respected in newer versions of kubeadm where v1beta4 is the default. ([#133753](https://github.com/kubernetes/kubernetes/pull/133753), [@HirazawaUi](https://github.com/HirazawaUi)) [SIG Cluster Lifecycle]...

- Kubeadm: fixed a bug when performing validation on `ClusterConfiguration` networking fields. ([#112751](https://github.com/kubernetes/kubernetes/pull/112751), [@SataQiu](https://github.com/SataQiu))

* kubeadm: v1beta2 InitConfiguration no longer embeds ClusterConfiguration it it. ([#77739](https://github.com/kubernetes/kubernetes/pull/77739), [@rosti](https://github.com/rosti))