- Added a new alpha API: ClusterTrustBundle (`certificates.k8s.io/v1alpha1`).
  A ClusterTrustBundle may be used to distribute [X.509](https://www.itu.int/rec/T-REC-X.509) trust anchors to workloads within the cluster. ([#113218](https://github.com/kubernetes/kubernetes/pull/113218), [@ahmedtd](https://github.com/ahmedtd)) [SIG API Machinery, Auth and Testing]

    version 1.9. Extended Resources (ERs) are a drop-in replacement for OIRs. You can use
    any domain name prefix outside of the `kubernetes.io/` domain instead of the
    `pod.alpha.kubernetes.io/opaque-int-resource-` prefix.

## Notable Features

### Workloads API (apps/v1beta2)

Kubernetes 1.8 adds the apps/v1beta2 group and version, which now consists of the

- Fixed runtime cost estimation for `x-int-or-string` custom resource schemas with maximum lengths. ([#132837](https://github.com/kubernetes/kubernetes/pull/132837), [@JoelSpeed](https://github.com/JoelSpeed))

	INSERTPS $7, X2, X11                    // 66440f3a21da07
	INSERTPS $7, X11, X11                   // 66450f3a21db07
	INSW                                    // 666d
	//TODO: INT $3                          // cc
	INT $7                                  // cd07
	INVD                                    // 0f08
	INVLPG (BX)                             // 0f013b
	INVLPG (R11)                            // 410f013b

- Introduces a new metric: `admission_webhook_request_total` with the following labels: name (string) - the webhook name, type (string) - the admission type, operation (string) - the requested verb, code (int) - the HTTP status code, rejected (bool) - whether the request was rejected, namespace (string) - the namespace of the requested resource. ([#103162](https://github.com/kubernetes/kubernetes/pull/103162), [@rmoriar1](https://github.com/rmoriar1))

    <acronym>JBIG2</acronym>
    <_comment>
      A lossless image compression standard from the
      Joint Bi-level Image Experts Group.
    </_comment>
    <tika:link>http://www.itu.int/rec/T-REC-T.88/en</tika:link>
    <magic priority="50">
      <match value="0x974A42320D0A1A0A" type="string" offset="0"/>
    </magic>
    <glob pattern="*.jb2"/>
    <glob pattern="*.jbig2"/>
  </mime-type>

## Changelog since v1.16.1

### Other notable changes

* Fixed panic when accessing CustomResources of a CRD with x-kubernetes-int-or-string. ([#83789](https://github.com/kubernetes/kubernetes/pull/83789), [@sttts](https://github.com/sttts))