- Added the `StorageVersionMigration` `v1beta1` API and removed the `v1alpha1` API.
  

*   The API group/version for the kube-proxy configuration has changed from `componentconfig/v1alpha1` to `kubeproxy.config.k8s.io/v1alpha1`. If you are using a config file for kube-proxy instead of the command line flags, you must change its apiVersion to `kubeproxy.config.k8s.io/v1alpha1`. ([#53645](https://github.com/kubernetes/kubernetes/pull/53645), [@xiangpengzhao](https://github.com/xiangpengzhao))

    * rbac.authorization.k8s.io/v1alpha1
    * settings.k8s.io/v1alpha1
    * If you wish to continue using them in v1.8, please enable them explicitly using the `--runtime-config` flag of the apiserver (for example, `--runtime-config="rbac.authorization.k8s.io/v1alpha1,settings.k8s.io/v1alpha1"`)

    * rbac.authorization.k8s.io/v1alpha1

    * settings.k8s.io/v1alpha1

    * If you wish to continue using them in v1.8, please enable them explicitly using the `--runtime-config` flag on the apiserver (for example, `--runtime-config="rbac.authorization.k8s.io/v1alpha1,settings.k8s.io/v1alpha1"`)

- Introduced scheduling.k8s.io/v1alpha2 Workload and PodGroup API to allow for expressing workload-level scheduling requirements and let kube-scheduler act on those. Removed scheduling.k8s.io/v1alpha1 Workload API. ([#136976](https://github.com/kubernetes/kubernetes/pull/136976), [@tosi3k](https://github.com/tosi3k)) [SIG API Machinery, Apps, Auth, CLI, Cloud Provider,...

- The `client.authentication.k8s.io/v1alpha1` ExecCredential has been removed. If you are using a client-go credential plugin that relies on the v1alpha1 API please contact the distributor of your plugin for instructions on how to migrate to the v1 API. ([#108616](https://github.com/kubernetes/kubernetes/pull/108616), [@margocrawf](https://github.com/margocrawf))

  to kubelet config ([#112136](https://github.com/kubernetes/kubernetes/pull/112136), [@pacoxu](https://github.com/pacoxu))
- `resource.k8s.io/v1alpha1` was replaced with `resource.k8s.io/v1alpha2`. Before
  upgrading a cluster, all objects in resource.k8s.io/v1alpha1 (ResourceClaim, ResourceClaimTemplate,
  ResourceClass, PodScheduling) must be deleted. The changes are internal, so

1.4 to 1.5, you must delete all `PodDisruptionBudget` objects (`policy/v1alpha1/PodDisruptionBudget`) that you have created. It is not possible to delete these objects after you upgrade, and their presence will prevent you from using the beta PodDisruptionBudget feature in 1.5 (which uses `policy/v1beta1/PodDisruptionBudget`). If you have already upgraded, you will need to downgrade the master to 1.4 to delete the `policy/v1alpha1/PodDisruptionBudget` objects.

## External Dependency Version...

    - [Client Binaries](#client-binaries-20)
    - [Server Binaries](#server-binaries-20)
  - [Changelog since v1.6.0-alpha.1](#changelog-since-v160-alpha1)
    - [Other notable changes](#other-notable-changes-23)
- [v1.6.0-alpha.1](#v160-alpha1)
  - [Downloads for v1.6.0-alpha.1](#downloads-for-v160-alpha1)
    - [Client Binaries](#client-binaries-21)
    - [Server Binaries](#server-binaries-21)
  - [Changelog since v1.5.0](#changelog-since-v150)

- Storage capacity tracking (= the CSIStorageCapacity feature) graduates to Beta and enabled by default, storage.k8s.io/v1alpha1/VolumeAttachment and storage.k8s.io/v1alpha1/CSIStorageCapacity objects are deprecated ([#99641](https://github.com/kubernetes/kubernetes/pull/99641), [@pohly](https://github.com/pohly))