## Changelog since v1.21.5

## Changes by Kind

### API Change

- Kube-apiserver: Fixes handling of CRD schemas containing literal null values in enums (#104989, @liggitt) [SIG API Machinery, Apps and Network]

### Feature

* Add port forwarding for rkt with kvm stage1 ([#32126](https://github.com/kubernetes/kubernetes/pull/32126), [@jjlakis](https://github.com/jjlakis))

nrstott, Nutti, Parag Jain, PeterLee, Philipp Jund, Rach L, Rafal Wojdyla,
Roland Zimmermann, Sergei Lebedev, SneakyFish5, Soila Kavulya, Sriram Veturi,
Steven Schmatz, Taehoon Lee, Tang, Wenyi, Taras Sereda, Ted Chang, Tim Zaman,
Tristan Rice, tucan, vchigrin, Vikram Tiwari, Vincent, WeberXie, William D.
Irons, Yan Facai (颜发才), Yong Tang, Yu Yi, Yuxin Wu, Zé ViníCius

# Release 1.9.0

* Eviction thresholds set to 0% or 100% will turn off eviction. ([#59681](https://github.com/kubernetes/kubernetes/pull/59681), [@mtaufen](https://github.com/mtaufen))

* CustomResourceDefinitions: OpenAPI v3 validation schemas containing `$ref`references are no longer permitted. Before upgrading, ensure CRD definitions do not include those `$ref` fields. ([#58438](https://github.com/kubernetes/kubernetes/pull/58438), [@carlory](https://github.com/carlory))

- Kube-apiserver: fixes a potential crash serving CustomResourceDefinitions that combine an invalid schema and CEL validation rules. ([#126167](https://github.com/kubernetes/kubernetes/pull/126167), [@cici37](https://github.com/cici37)) [SIG API Machinery and Testing]

* federation: Add admission controller for policy-based placement ([#44786](https://github.com/kubernetes/kubernetes/pull/44786), [@tsandall](https://github.com/tsandall))
* Get command uses OpenAPI schema to enhance display for a resource if run with flag 'use-openapi-print-columns'.  ([#46235](https://github.com/kubernetes/kubernetes/pull/46235), [@droot](https://github.com/droot))
    * An example command:

- Fixed an issue in register-gen where imports for k8s.io/apimachinery/pkg/runtime and k8s.io/apimachinery/pkg/runtime/schema were missing. ([#130392](https://github.com/kubernetes/kubernetes/pull/130392), [@mrIncompetent](https://github.com/mrIncompetent)) [SIG API Machinery]

## Changelog since v1.22.2

## Changes by Kind

### API Change

- Kube-apiserver: Fixes handling of CRD schemas containing literal null values in enums (#104988, @liggitt) [SIG API Machinery, Apps and Network]

### Feature

## Changes by Kind

### API Change

- The list-type of the alpha resourceClaims field introduced to Pods in 1.26.0 was modified from "set" to "map", resolving an incompatibility with use of this schema in CustomResourceDefinitions and with server-side apply. ([#114617](https://github.com/kubernetes/kubernetes/pull/114617), [@JoelSpeed](https://github.com/JoelSpeed)) [SIG API Machinery]

### Feature