how we can support developers with tooling built on top of `kubectl exec`. The addition of the `kubectl debug` [command](https://github.com/kubernetes/enhancements/blob/master/keps/sig-cli/1441-kubectl-debug/README.md) (it is alpha but your feedback is more than welcome), allows developers to easily debug their Pods inside the cluster. We think this addition is invaluable.  This command allows one to create a temporary container which runs next to the Pod one is trying to examine, but also attaches...

- If a bad flag is supplied to a kubectl command, only a tip to run `--help` is printed, instead of the usage menu.  Usage menu is printed upon running `kubectl command --help`. ([#82423](https://github.com/kubernetes/kubernetes/pull/82423), [@sallyom](https://github.com/sallyom))

- 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))

- Kubeadm: deprecate self-hosting support. The experimental command "kubeadm alpha self-hosting" is now deprecated and will be removed in a future release. ([#95125](https://github.com/kubernetes/kubernetes/pull/95125), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

- 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

- kubeadm: if an unknown command name is passed to any parent command such as 'kubeadm init phase' return an error. If 'kubeadm init phase' or another command that has subcommands is called without subcommand name, print the available commands and also return an error. ([#127096](https://github.com/kubernetes/kubernetes/pull/127096), [@neol...

- Kubeadm: deprecated command "alpha selfhosting pivot" is now removed. ([#97627](https://github.com/kubernetes/kubernetes/pull/97627), [@knight42](https://github.com/knight42))

* 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.

#### Updates to apply
* New command `apply set-last-applied` *updates the applied-applied-configuration annotation* ([#41694](https://github.com/kubernetes/kubernetes/pull/41694), [@shiywang](https://github.com/shiywang))

* `kubectl wait` is a new command that allows waiting for one or more resources to be deleted or to reach a specific condition. It adds a `kubectl wait --for=[delete|condition=condition-name] resource/string` command. ([#64034](https://github.com/kubernetes/kubernetes/pull/64034), [@deads2k](https://github.com/deads2k))