### SIG Instrumentation

* Added prometheus cluster monitoring addon to kube-up. ([#62195](https://github.com/kubernetes/kubernetes/pull/62195), [@serathius](https://github.com/serathius))
* Kubelet now exposes a new endpoint, `/metrics/probes`, which exposes a Prometheus metric containing the liveness and/or readiness probe results for a container. ([#61369](https://github.com/kubernetes/kubernetes/pull/61369), [@rramkumar1](https://github.com/rramkumar1))

- HPA controller exposes the following metrics from the kube-controller-manager. 
  - `metric_computation_duration_seconds`: The time(seconds) that the HPA controller takes to calculate one metric.

- Add `csi_operations_seconds` metric on kubelet that exposes CSI operations duration and status for node CSI operations. ([#98979](https://github.com/kubernetes/kubernetes/pull/98979), [@Jiawei0227](https://github.com/Jiawei0227)) [SIG Instrumentation and Storage]

#### **Hardware Accelerators**

*   Kubelet now exposes metrics for NVIDIA GPUs attached to the containers. ([#55188](https://github.com/kubernetes/kubernetes/pull/55188),[ @mindprince](https://github.com/mindprince))

* The Metrics Server now exposes metrics via the /metric endpoint. These metrics are in the prometheus format.  ([#57456](https://github.com/kubernetes/kubernetes/pull/57456), [@kawych](https://github.com/kawych))

 Extended resources cannot be overcommitted, so make sure that request and limit are equal
 if both are present in a container spec.

 - The default Bootstrap Token created with `kubeadm init` v1.8 expires
 and is deleted after 24 hours by default to limit the exposure of the
 valuable credential. You can create a new Bootstrap Token with
 `kubeadm token create` or make the default token permanently valid by specifying

- Exposes and sets a default timeout for the SubjectAccessReview client for DelegatingAuthorizationOptions ([#96152](https://github.com/kubernetes/kubernetes/pull/96152), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery and Cloud Provider]

- CRI: exposed commit memory bytes in container stats specific to Windows ([#119238](https://github.com/kubernetes/kubernetes/pull/119238), [@kiashok](https://github.com/kiashok))
- 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

- Kubelet now exposes `/debug/flags/v` to allow dynamically setting glog logging level.  For example, to change glog level to 3, you only have to send a PUT request like `curl -X PUT http://127.0.0.1:8080/debug/flags/v -d "3"`. ([#64601](https://github.com/kubernetes/...

- Exposes and sets a default timeout for the SubjectAccessReview client for DelegatingAuthorizationOptions ([#96153](https://github.com/kubernetes/kubernetes/pull/96153), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery and Cloud Provider]