- [**API Machinery**](#api-machinery-3)
      - [**Admission Control**](#admission-control)
      - [**API & API server**](#api-&-api-server)
      - [**Audit**](#audit)
      - [**Custom Resources**](#custom-resources)
      - [**Other**](#other)
    - [**Apps**](#apps-1)
    - [**Auth**](#auth-3)
      - [**Audit**](#audit-1)
      - [**RBAC**](#rbac)
      - [**Other**](#other-1)
      - [**GCE**](#gce)

`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...

    * New docs section: [Custom Request and APIRoute class](https://fastapi.tiangolo.com/advanced/custom-request-and-route/).
    * PR [#589](https://github.com/tiangolo/fastapi/pull/589) by [@dmontagu](https://github.com/dmontagu).

* kubectl could scale custom resource again ([#81342](https://github.com/kubernetes/kubernetes/pull/81342), [@knight42](https://github.com/knight42))

- Fixes conversion error in multi-version custom resources that could cause metadata.generation to increment on no-op patches or updates of a custom resource. ([#88995](https://github.com/kubernetes/kubernetes/pull/88995), [@liggitt](https://github.com/liggitt)) [SIG API Machinery]

- Fixes an issue that can result in namespaced custom resources being orphaned when their namespace is deleted, if the CRD defining the custom resource is removed concurrently with namespaces being deleted, then recreated. ([#93790](https://github.com/kubernetes/kubernetes/pull/93790), [@liggitt](https://github.com/liggitt)) [SIG API Machinery...

- The rules for incrementing `metadata.generation` of custom resources changed: ([#69059](https://github.com/kubernetes/kubernetes/pull/69059), [@caesarxuchao](https://github.com/caesarxuchao))
  - If the custom resource participates the spec/status convention, the metadata.generation of the CR increments when there is any change, except for the changes to the metadata or the changes to the status.

- API paging is now enabled for custom resource definitions, custom resources and APIService objects. ([#67861](https://github.com/kubernetes/kubernetes/pull/67861), [@liggitt](https://github.com/liggitt))

- Now users can get object info like:

  ```bash
    a. kubectl get pod test-pod -o custom-columns=CONTAINER:.spec.containers[0:3].name
    b. kubectl get pod test-pod -o custom-columns=CONTAINER:.spec.containers[-2:].name
  ```

([#73063](https://github.com/kubernetes/kubernetes/pull/73063), [@WanLinghao](https://github.com/WanLinghao))

- Fixes a bug at kube-apiserver start where APIService objects for custom resources could be deleted and recreated. ([#118104](https://github.com/kubernetes/kubernetes/pull/118104), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Testing]