- Component owner can configure the allowlist of metric label with flag '--allow-metric-labels'. ([#99385](https://github.com/kubernetes/kubernetes/pull/99385), [@YoyinZyc](https://github.com/YoyinZyc)) [SIG API Machinery, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation and Release]

- 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.

- Registered_metric_total, disabled_metric_total, hidden_metric_total & kubernetes_feature_enabled are promoted to `BETA` stability. ([#119264](https://github.com/kubernetes/kubernetes/pull/119264), [@logicalhan](https://github.com/logicalhan)) [SIG API Machinery, Architecture, Cluster Lifecycle...

- resource metrics endpoint `/metrics/resource/v1alpha1` as well as all metrics under this endpoint have been deprecated. Please convert to the following metrics emitted by endpoint `/metrics/resource`:
  - scrape_error --> scrape_error
  - node_cpu_usage_seconds_total --> node_cpu_usage_seconds

* 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))

* Migrate the metrics/v1alpha1 API to metrics/v1beta1.  The HorizontalPodAutoscaler ([#51653](https://github.com/kubernetes/kubernetes/pull/51653), [@DirectXMan12](https://github.com/DirectXMan12))
    * controller REST client now uses that version.  For v1beta1, the API is now known as
    * resource-metrics.metrics.k8s.io.

`autoscaling/v2alpha1`. The Horizontal Pod Autoscaler changes include support for status conditions, and autoscaling on memory and custom metrics.

* The metrics APIs, `custom-metrics.metrics.k8s.io` and `metrics`, were moved from `v1alpha1` to `v1beta1`, and renamed to `custom.metrics.k8s.io` and `metrics.k8s.io`, respectively. If you have deployed a custom metrics adapter, ensure that it supports the new API version. If you have deployed Heapster in aggregated API server mode, upgrade Heapster...

* Flex drivers by default do not produce metrics. Flex plugins can enable metrics collection by setting  the capability 'supportsMetrics' to true. Make sure the file system can support fs stat to produce metrics in this case. ([#67508](https://github.com/kubernetes/kubernetes/pull/67508), [@brahmaroutu](https://github.com/brahmaroutu))

### Pod resource metrics

On-demand metrics calculation is now available through `/metrics/resources`. [When enabled](
https://docs.k8s.io/concepts/cluster-administration/system-metrics#kube-scheduler-metrics), the endpoint will report the requested resources and the desired limits of all running pods.

### Introducing `RootCAConfigMap`

      - [Network](#network)
      - [Node](#node)
      - [Storage](#storage)
    - [Deprecations and Removals](#deprecations-and-removals)
    - [Metrics Changes](#metrics-changes)
      - [Added metrics](#added-metrics)
      - [Deprecated/changed metrics](#deprecated/changed-metrics)
    - [Notable Features](#notable-features)
      - [Stable](#stable)
      - [Beta](#beta)
      - [Alpha](#alpha)
- [v1.15.0-beta.1](#v1150-beta1)