- `kubelet_pleg_relist_interval_microseconds` -> `kubelet_pleg_relist_interval_seconds`
      - `kubelet_eviction_stats_age_microseconds` -> `kubelet_eviction_stats_age_seconds`
      - `kubelet_runtime_operations` -> `kubelet_runtime_operations_total`
      - `kubelet_runtime_operations_latency_microseconds` -> `kubelet_runtime_operations_duration_seconds`

- Kubectl: Fixed panic when describing an ingress backend without an API Group ([#100505](https://github.com/kubernetes/kubernetes/pull/100505), [@lauchokyip](https://github.com/lauchokyip)) [SIG CLI]
- Kubectl: fix case of age column in describe node (#96963, @bl-ue) ([#96963](https://github.com/kubernetes/kubernetes/pull/96963), [@bl-ue](https://github.com/bl-ue)) [SIG CLI]

    * --docker_env_metadata_whitelist
    * --docker_only
    * --docker-tls
    * --docker-tls-ca
    * --docker-tls-cert
    * --docker-tls-key
    * --enable_load_reader
    * --event_storage_age_limit
    * --event_storage_event_limit
    * --global_housekeeping_interval
    * --google-json-key
    * --log_cadvisor_usage
    * --machine_id_file
    * --storage_driver_user

- Kubelet: Added kubelet serving certificate metric `server_rotation_seconds` which is a histogram reporting the age of a just rotated serving certificate in seconds. ([#84534](https://github.com/kubernetes/kubernetes/pull/84534), [@sambdavidson](https://github.com/sambdavidson))

- `kubelet_pleg_relist_latency_microseconds` -> `kubelet_pleg_relist_duration_seconds`
- `kubelet_pleg_relist_interval_microseconds` -> `kubelet_pleg_relist_interval_seconds`
- `kubelet_eviction_stats_age_microseconds` -> `kubelet_eviction_stats_age_seconds`
- `kubelet_runtime_operations` -> `kubelet_runtime_operations_total`
- `kubelet_runtime_operations_latency_microseconds` -> `kubelet_runtime_operations_duration_seconds`

- Added `ImageMaximumGCAge` field to Kubelet configuration, which allows a user to set the maximum age an image is unused before it's garbage collected. ([#121275](https://github.com/kubernetes/kubernetes/pull/121275), [@haircommander](https://github.com/haircommander))

- Change `kubectl diff --invalid-arg` status code from 1 to 2 to match docs ([#105445](https://github.com/kubernetes/kubernetes/pull/105445), [@ardaguclu](https://github.com/ardaguclu))
- Changed kubectl describe to compute age of an event using the `EventSeries.count` and `EventSeries.lastObservedTime`. ([#104482](https://github.com/kubernetes/kubernetes/pull/104482), [@harjas27](https://github.com/harjas27))

- Added a "reason" field to the "image_garbage_collected_total" metric, allowing administrators to differentiate between images that were collected for reasons "age" vs "space".
   ([#123345](https://github.com/kubernetes/kubernetes/pull/123345), [@haircommander](https://github.com/haircommander))