from 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...

- **Auth**
  - [alpha] Container Image Policy allows an access controller to determine whether a pod may be scheduled based on a policy ([docs](http://kubernetes.io/docs/admin/admission-controllers/#imagepolicywebhook)) ([kubernetes/features#59](https://github.com/kubernetes/enhancements/issues/59))

   ([#123179](https://github.com/kubernetes/kubernetes/pull/123179), [@aramase](https://github.com/aramase))
- Added feature gate `MutatingAdmissionPolicy` for enabling mutation policy in admission chain. ([#123425](https://github.com/kubernetes/kubernetes/pull/123425), [@cici37](https://github.com/cici37))