* You must now specify `Node.Spec.ConfigSource.ConfigMap.KubeletConfigKey` when using dynamic Kubelet config to tell the Kubelet which key of the `ConfigMap` identifies its config file. ([#59847](https://github.com/kubernetes/kubernetes/pull/59847), [@mtaufen](https://github.com/mtaufen))

```

If your cluster was installed by kubeadm, you should edit the `featureGates` field in the `kubeadm-config` ConfigMap. You can do this using `kubectl -n kube-system edit cm kubeadm-config` before upgrading. For example:

kubeadm-config Before:

```
apiVersion: v1
kind: ConfigMap
metadata:
  name: kubeadm-config
data:
  MasterConfiguration: |
    kubeProxy:
      config:

* Native support for token based bootstrap flow.  This includes signing a well known ConfigMap in the `kube-public` namespace and cleaning out expired tokens. ([#36101](https://github.com/kubernetes/kubernetes/pull/36101), [@jbeda](https://github.com/jbeda))

### ConfigMap

- Resolves spurious `Failed to list *v1.Secret` or `Failed to list *v1.ConfigMap` messages in kubelet logs. ([#99538](https://github.com/kubernetes/kubernetes/pull/99538), [@liggitt](https://github.com/liggitt)) [SIG Auth and Node]

    * `kubectl version` now supports `--output` ([#39858](https://github.com/kubernetes/kubernetes/pull/39858), [@alejandroEsc](https://github.com/alejandroEsc))

    * `kubectl create configmap` has a new option `--from-env-file` that populates a configmap from file which follows a key=val format for each line. ([#38882](https://github.com/kubernetes/kubernetes/pull/38882), [@fraenkel](https://github.com/fraenkel))

* Release the kubelet client certificate rotation as beta. ([#51045](https://github.com/kubernetes/kubernetes/pull/51045), [@jcbsmpsn](https://github.com/jcbsmpsn))
* Adds --append-hash flag to kubectl create configmap/secret, which will append a short hash of the configmap/secret contents to the name during creation. ([#49961](https://github.com/kubernetes/kubernetes/pull/49961), [@mtaufen](https://github.com/mtaufen))

### Immutable Secrets and ConfigMaps

Immutable Secrets and ConfigMaps graduates to GA. This feature allows users to specify that the contents of a particular Secret or ConfigMap is immutable for its object lifetime. For such instances, Kubelet will not watch/poll for changes and therefore reducing apiserver load.

### Structured Logging in Kubelet

* Release the kubelet client certificate rotation as beta. ([#51045](https://github.com/kubernetes/kubernetes/pull/51045), [@jcbsmpsn](https://github.com/jcbsmpsn))
* Adds --append-hash flag to kubectl create configmap/secret, which will append a short hash of the configmap/secret contents to the name during creation. ([#49961](https://github.com/kubernetes/kubernetes/pull/49961), [@mtaufen](https://github.com/mtaufen))

  
  v1beta3 is now marked as deprecated but will continue to be supported until version 1.34 or later.
  The storage configuration in the kube-system/kubeadm-config ConfigMap is now a v1beta4 ClusterConfiguration. ([#125029](https://github.com/kubernetes/kubernetes/pull/125029), [@neolit123](https://github.com/neolit123))

- kube-proxy...