*   Clients using older endpoints will be unaffected. This change is only at the REST API level and is independent of the default behavior of particular clients (e.g. this does not affect the default for the kubectl `--cascade` flag).

   verbosity at runtime for JSON output. ([#114609](https://github.com/kubernetes/kubernetes/pull/114609), [@pohly](https://github.com/pohly))

* apiserver: fixes handling and logging of panics in REST handlers to prevent crashes ([#71076](https://github.com/kubernetes/kubernetes/pull/71076), [@liggitt](https://github.com/liggitt))

### Feature

- The following deprecated metrics are removed, please convert to the corresponding metrics:
  - The following replacement metrics are available from v1.14.0:
      - `rest_client_request_latency_seconds` -> `rest_client_request_duration_seconds`
      - `scheduler_scheduling_latency_seconds` -> `scheduler_scheduling_duration_seconds `
      - `docker_operations` -> `docker_operations_total`

- Client-go now exposes two new metrics to monitor the client-go logic that
  generate http.Transports for the clients.
  
  - `rest_client_transport_cache_entries` is a gauge metric
  with the number of existing entries in the internal cache
  
  - `rest_client_transport_create_calls_total` is a counter
  that increments each time a new transport is created, storing

   - In version 1.8, enable this behavior by setting the
     `--horizontal-pod-autoscaler-use-rest-clients` flag to `true`.

   - In version 1.9, this behavior will be enabled by default, and must be explicitly
     disabled by setting the `--horizontal-pod-autoscaler-use-rest-clients` flag to `false`.

### Cluster Lifecycle

* client-go: restores behavior of populating the BearerToken field in rest.Config objects constructed from kubeconfig files containing tokenFile config, or from in-cluster configuration. An additional BearerTokenFile field is now populated to enable constructed clients to periodically refresh tokens. ([#71713](https://gi...

 - reach GA, and deprecate the beta, or
 - have a new beta version _(and deprecate the previous beta)_.

- Client-go metrics: change bucket distribution for `rest_client_request_duration_seconds` and `rest_client_rate_limiter_duration_seconds` from [0.001, 0.002, 0.004, 0.008, 0.016, 0.032, 0.064, 0.128, 0.256, 0.512] to [0.005, 0.025, 0.1, 0.25, 0.5, 1.0, 2.0, 4.0, 8.0, 15.0, 30.0, 60.0}] ([#106911](https://github.com/kubernete...