- Kubelet config file will be backed up to `/etc/kubernetes/tmp/` folder with `kubeadm-kubelet-config` append with a random suffix as the filename ([#114695](https://github.com/kubernetes/kubernetes/pull/114695), [@chendave](https://github.com/chendave)) [SIG Cluster Lifecycle]

- `kubeadm`: added a new "kubeadm config validate" command that can be used to
  validate any input config file. Use the `--config` flag to pass a config file
  to it. See the command `--help` screen for more information. As a result of adding
  this new command, enhance the validation capabilities of the existing "kubeadm

The Kubelet now exports metrics that report the assigned (`node_config_assigned`), last-known-good (`node_config_last_known_good`), and active (`node_config_active`) config sources, and a metric indicating whether the node is experiencing a config-related error (`node_config_error`). The config source metrics always report the value `1`, and carry the `node_config_name`, `node_config_uid`, `node_config_resource_version`, and `node_config_kubelet_key labels`, which identify the config version. The error...

   * -viper-config can be used to set also the options defined by command line flags
   * the default config file is "e2e.yaml/toml/json/..." and the test starts when no such config is found (as before) but if -viper-config is used, the config file must exist
   * -viper-config can be used to select a file with full path, with or without file suffix

- Kubeadm: `kubeadm config view` command has been deprecated and will be removed in a feature release, please use `kubectl get cm -o yaml -n kube-system kubeadm-config` to get the kubeadm config directly ([#92740](https://github.com/kubernetes/kubernetes/pull/92740), [@SataQiu](https://github.com/SataQiu)) [SIG Cluster Lifecycle]

- The legacy scheduler policy config is removed in v1.23, the associated flags `policy-config-file`, `policy-configmap`, `policy-configmap-namespace` and `use-legacy-policy-config` are also removed. Migrate to Component Config instead, see https://kubernetes.io/docs/reference/scheduling/config/ for details. ([#105424](https://github.com/kubernetes/kubernetes/pull/105424), [@kerthcet](https://github.com/kerthcet))...

    * Added --config-map and --config-map-namespace command line options.
    * If --config-map is set, kube-dns will load dynamic configuration from the config map
      referenced by --config-map-namespace, --config-map. The config-map supports
      the following properties: "federations".
    * --federations flag is now deprecated. Prefer to set federations via the config-map.

feature by default. This implies that 1) for new clusters kubeadm will start using the `kube-system/kubelet-config` naming scheme for the kubelet ConfigMap and RBAC rules, instead of the legacy `kubelet-config-x.yy` naming. 2) during upgrade, kubeadm will only write the new scheme ConfigMap and RBAC objects. To disable the feature you can pass `UnversionedKubeletConfigMap: false` in the kubeadm config for new clusters. For upgrade on existing clusters you can also override the behavior by patching the...

`init` and `join` it is now recommended that you migrate to configure patches via `{Init|Join}Configuration.patches.directory`. For the time being, these flags can be mixed with `--config`, but that might change in the future. On a command line, the last *patches flag takes precedence over previous flags and the value in config. `kubeadm upgrade --patches` will continue to be the only available option, since `upgrade` does not support a configuration file yet. ([#103063](https://github.com/kubernetes...

kubelet related ConfigMap and RBAC rules are now locked to have a simplified naming `*kubelet-config` instead of the legacy naming `*kubelet-config-x.yy`, where `x.yy` was the version of the control plane. If you have previously used the old naming format with `UnversionedKubeletConfigMap=false`, you must manually copy the config map from `kube-system/kubelet-config-x.yy` to `kube-system/kubelet-config` before upgrading to `v1.25`. ([#110327](https://github.com/kubernetes/kubernetes/pull/110327),...