- Alpha implementation of Kubectl Command Headers: SIG CLI KEP 859 enabled when KUBECTL_COMMAND_HEADERS environment variable set on the client command line.
  - To enable: export KUBECTL_COMMAND_HEADERS=1; kubectl ... ([#98952](https://github.com/kubernetes/kubernetes/pull/98952), [@seans3](https://github.com/seans3)) [SIG API Machinery and CLI]

  // +optional
  optional string host = 2;
}

// ExecAction describes a "run in container" action.
message ExecAction {
  // Command is the command line to execute inside the container, the working directory for the
  // command  is root ('/') in the container's filesystem. The command is simply exec'd, it is
  // not run inside a shell, so traditional shell instructions ('|', etc) won't work. To use

- Kubeadm: remove the deprecated command `kubeadm config view`. A replacement for this command is `kubectl get cm -n kube-system kubeadm-config -o=jsonpath="{.data.ClusterConfiguration}"` ([#102071](https://github.com/kubernetes/kubernetes/pull/102071), [@neolit123](https://github.com/neolit123))

  spec with the `--serviceaccount` flag.

- `kubectl proxy` now correctly handles the `exec`, `attach`, and
  `portforward` commands.  You must pass `--disable-filter` to the command to allow these commands.

- Added `cronjobs.batch` to "all", so that `kubectl get all` returns them.

- Added flag `--include-uninitialized` to `kubectl annotate`, `apply`, `edit-last-applied`,

- `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

* kubeadm: a new command `kubeadm upgrade node` is introduced for upgrading nodes (both secondary control-plane nodes and worker nodes)  ([#78408](https://github.com/kubernetes/kubernetes/pull/78408), [@fabriziopandini](https://github.com/fabriziopandini))
    * The command `kubeadm upgrade node config` is now deprecated; use `kubeadm upgrade node` instead.

- kube-scheduler dropped support for configuration files with apiVersion `componentconfig/v1alpha1`. Ensure kube-scheduler is configured using command-line flags or a configuration file with apiVersion `kubescheduler.config.k8s.io/v1alpha1` before upgrading to 1.13.
- kubectl

tes/pull/58171), [@verult](https://github.com/verult))

* Default values differ between the Kubelet's componentconfig (config file) API and the Kubelet's command line. Be sure to review the default values when migrating to using a config file. For example, the authz mode is set to "AlwaysAllow" if you rely on the command line, but defaults to the more secure "Webhook" mode if you load config from a file. ([#59666](https://github.com/kubernetes/kubernetes/pull/59666), [@mtaufen](https...

- Kubeadm: allow the `certs check-expiration` command to not require the existence of the cluster CA key (ca.key file) when checking the expiration of managed certificates in kubeconfig files. ([#106854](https://github.com/kubernetes/kubernetes/pull/106854), [@neolit123](https://github.com/neolit123))

- Added categories column to the `kubectl api-resources` command's wide output (`-o wide`).