### Other (Cleanup or Flake)

- Added: Log Line for Debugging possible merge errors for Kubelet related Config requests. ([#124389](https://github.com/kubernetes/kubernetes/pull/124389), [@holgerson97](https://github.com/holgerson97)) [SIG Node]

- `kubectl` now contains a `kubectl alpha debug` command. This command allows attaching an ephemeral container to a running pod for the purposes of debugging. ([#88004](https://github.com/kubernetes/kubernetes/pull/88004), [@verb](https://github.com/verb)) [SIG CLI]

  - [alpha] Access Review APIs expose authorization engine to external inquiries for delegation, inspection, and debugging ([docs](http://kubernetes.io/docs/admin/authorization/)) ([kubernetes/features#37](https://github.com/kubernetes/enhancements/issues/37))
- **Cluster Lifecycle**

                        - destination
                        type: object
                      type: array
                    name:
                      description: The name assigned to the route for debugging purposes.
                      type: string
                    redirect:
                      description: A HTTP rule can either return a direct_response,

- When specifying an invalid value for a label, it was not always clear which label the value was specified for. Starting with this release, the label's key is included in such error messages, which makes debugging easier. ([#77144](https://github.com/kubernetes/kubernetes/pull/77144), [@kenegozi](https://github.com/kenegozi))

* The `--insecure-allow-any-token` flag has been removed from the API server. Users of the flag should use impersonation headers instead for debugging. ([#49045](https://github.com/kubernetes/kubernetes/pull/49045), [@ericchiang](https://github.com/ericchiang))

    *   CRI now supports debugging via a verbose option for status functions. ([#53965](https://github.com/kubernetes/kubernetes/pull/53965), [@Random-Liu](https://github.com/Random-Liu))

- Exposed the `apiserver_watch_cache_resource_version` metric to simplify debugging problems with watchcache. ([#125377](https://github.com/kubernetes/kubernetes/pull/125377), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery and Instrumentation]

- The `kubelet` now reports distinguishes log messages about certificate rotation for its client cert and server cert separately to make debugging problems with one or the other easier. ([#101252](https://github.com/kubernetes/kubernetes/pull/101252), [@smarterclayton](https://github.com/smarterclayton))

- Ephemeral containers have been added in alpha. These temporary containers can be added to running pods for purposes such as debugging, similar to how `kubectl exec` runs a process in an existing container. Also like `kubectl exec`, no resources are reserved for ephemeral containers and they are not restarted when they exit. Note that container namespace targeting is not yet implemented,...