gate UnversionedKubeletConfigMap. When this feature is enabled kubeadm will start using a new naming format for the ConfigMap where it stores the KubeletConfiguration structure. The old format included the Kubernetes version - "kube-system/kubelet-config-1.22", while the new format does not - "kube-system/kubelet-config". A similar formatting change is done for the related RBAC rules. The old format is now DEPRECATED and will be removed after the feature graduates to GA. When writing the ConfigMap...

* RBAC objects are now stored in etcd in v1 format. After completing an upgrade to 1.9, RBAC objects (Roles, RoleBindings, ClusterRoles, ClusterRoleBindings) should be migrated to ensure all persisted objects are written in `v1` format, prior to `v1alpha1` support being removed in a future release. ([#52950](https://github.com/kubernetes/kubernetes/pull/52950), [@liggitt](https://github.com/liggitt))...

* Fixes bugs that make apiserver panic when aggregating valid but not well formed OpenAPI spec ([#63635](https://github.com/kubernetes/kubernetes/pull/63635), [@roycaihw](https://github.com/roycaihw))

    * `kubectl create secret` has a new option `--from-env-file` that populates a secret from file which follows a key=val format for each line.

  * Printing/describe

- Kubeadm: allow RSA and ECDSA format keys in preflight check ([#112537](https://github.com/kubernetes/kubernetes/pull/112537), [@SataQiu](https://github.com/SataQiu)) [SIG Cluster Lifecycle]

## Dependencies

### Added
_Nothing has changed._

- Fixed prerelease lifecycle for `PodCertificateRequest`. ([#133350](https://github.com/kubernetes/kubernetes/pull/133350), [@carlory](https://github.com/carlory))

- Kubeadm: now supports image repository format validation. ([#112732](https://github.com/kubernetes/kubernetes/pull/112732), [@SataQiu](https://github.com/SataQiu))

- Kubeadm: allow RSA and ECDSA format keys in preflight check ([#112535](https://github.com/kubernetes/kubernetes/pull/112535), [@SataQiu](https://github.com/SataQiu)) [SIG Cluster Lifecycle]

## Dependencies

### Added
_Nothing has changed._

# Kubernetes v1.15 Release Notes

## 1.15 What’s New

A complete changelog for the release notes is now hosted in a customizable format at [https://relnotes.k8s.io/](https://relnotes.k8s.io/?releaseVersions=1.15.0). Check it out and please give us your feedback!

  - support for the `v1alpha3` configuration file format is deprecated and will be removed in 1.14. Use `kubeadm config migrate` to migrate `v1alpha3` configuration files to `v1beta1`, which provides improvements in image repository management, addons configuration, and other areas. The documentation for...