- kubeadm: Default component configs are now printable via kubeadm config print-default ([#66074](https://github.com/kubernetes/kubernetes/pull/66074), [@rosti](https://github.com/rosti)) Courtesy of SIG Cluster Lifecycle

*   The API group/version for the kube-proxy configuration has changed from `componentconfig/v1alpha1` to `kubeproxy.config.k8s.io/v1alpha1`. If you are using a config file for kube-proxy instead of the command line flags, you must change its apiVersion to `kubeproxy.config.k8s.io/v1alpha1`. ([#53645](https://github.com/kubernetes/kubernetes/pull/53645), [@xiangpengzhao](https://github.com/xiangpengzhao))

- Kubeadm:  'kubeadm alpha kubelet config download' has been removed, please use 'kubeadm upgrade node phase kubelet-config' instead ([#87944](https://github.com/kubernetes/kubernetes/pull/87944), [@SataQiu](https://github.com/SataQiu)) [SIG Cluster Lifecycle]

- Add flag --lease-max-object-size and metric etcd_lease_object_counts for kube-apiserver to config and observe max objects attached to a single etcd lease. ([#97480](https://github.com/kubernetes/kubernetes/pull/97480), [@lingsamuel](https://github.com/lingsamuel)) [SIG API Machinery, Instrumentation and Scalability]

kubeadm-config Before:

```
apiVersion: v1
kind: ConfigMap
metadata:
  name: kubeadm-config
data:
  MasterConfiguration: |
    kubeProxy:
      config:
        featureGates: "SupportIPVSProxyMode=true"
```

## Changelog since v1.8.14

### Action Required

* ACTION REQUIRED: Kubernetes JSON deserializer is now case-sensitive to restore compatibility with pre-1.8 servers. If your config files contains fields with wrong case, the config files will be now invalid. ([#65410](https://github.com/kubernetes/kubernetes/pull/65410), [@nikhita](https://github.com/nikhita))

### Other notable changes

_hash_status_last_timestamp_seconds`, `apiserver_encryption_config_controller_automatic_reload_failures_total`, `apiserver_encryption_config_controller_automatic_reload_success_total`, `apiserver_encryption_config_controller_automatic_reload_last_timestamp_seconds`.
  
  Fixed bug to surface events for the following metrics: `apiserver_encryption_config_controller_automatic_reload_failures_total`, `apiserver_encryption_config_controller_automatic_reload_last_timestamp_seconds`, `apiser...

* kubeadm: remove deprecated kubeadm config print-defaults command ([#71467](https://github.com/kuberne...

    * rbac.authorization.k8s.io/v1alpha1

    * settings.k8s.io/v1alpha1

    * If you wish to continue using them in v1.8, please enable them explicitly using the `--runtime-config` flag on the apiserver (for example, `--runtime-config="rbac.authorization.k8s.io/v1alpha1,settings.k8s.io/v1alpha1"`)

- KMS: added validation for duplicate kms config name when auto reload is enabled. If you enabled automatic reload of encryption configuration with API server flag `--encryption-provider-config-automatic-reload`, ensure all the KMS provider names (v1 and v2) in the encryption configuration...