- 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))

    - [Garbage Collector](#garbage-collector)
    - [kubeadm](#kubeadm-2)
    - [kubectl](#kubectl-1)
      - [New Commands](#new-commands)
      - [Create subcommands](#create-subcommands)
      - [Updates to existing commands](#updates-to-existing-commands)
      - [Updates to apply](#updates-to-apply)
      - [Updates to edit](#updates-to-edit)
      - [Bug fixes](#bug-fixes)

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...

### CLI Improvements

- Added `kubeadm upgrade node`. This command can be used to upgrade both secondary control-plane nodes and worker nodes. The `kubeadm upgrade node config` and `kubeadm upgrade node experimental-control-plane` commands are now deprecated. ([#78408](https://github.com/kubernetes/kubernetes/pull/78408), [@fabriziopandini](https://github.com/fabriziopandini))

- 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), [@neolit123](https://github.com/neolit123)) [SIG...

  - kubeadm now handles air-gapped environments by using the local client version as a fallback.
  - Some kubeadm commands are now allowed to work in a completely offline mode.
- Certificate handling improvements:
  - Renew certs as part of upgrade.
  - New `kubeadm alpha phase certs renew` command for renewing certificates.
  - Certificates created with kubeadm now have improved uniqueness of Distinguished Name fields.

- Action-required: kubeadm: remove the deprecated feature --experimental-kustomize from kubeadm commands. The feature was replaced with --experimental-patches...

- Added label selector flag to all `kubectl rollout` commands. ([#99758](https://github.com/kubernetes/kubernetes/pull/99758), [@aramperes](https://github.com/aramperes))
- Added more message for no PodSandbox container. ([#107116](https://github.com/kubernetes/kubernetes/pull/107116), [@yxxhero](https://github.com/yxxhero))

- The helping message of commands which have sub-commands is now clearer and more instructive. It will show the full command instead of `kubectl <command> --help ...`
  

- kubeadm has graduated `kubeadm alpha phase` commands to `kubeadm init phase`. This means that the phases of creating a control-plane node are now tightly integrated as part of the `init` command. Alpha features, not yet ready for GA are still kept under `kubeadm alpha` and we appreciate feedback on them.