* The following alpha API groups were unintentionally enabled by default in previous releases, and will no longer be enabled by default in v1.8: ([#47690](https://github.com/kubernetes/kubernetes/pull/47690), [@caesarxuchao](https://github.com/caesarxuchao))

    * rbac.authorization.k8s.io/v1alpha1

    * settings.k8s.io/v1alpha1

* The following alpha API groups were unintentionally enabled by default in previous releases, and will no longer be enabled by default in v1.8: ([#47690](https://github.com/kubernetes/kubernetes/pull/47690), [@caesarxuchao](https://github.com/caesarxuchao))
    * rbac.authorization.k8s.io/v1alpha1
    * settings.k8s.io/v1alpha1

1.6 continues to support the alpha `scheduler.alpha.kubernetes.io/affinity` annotation on the Pod if you explicitly enable the alpha feature "AffinityInAnnotations", but it will be removed in a future release. When you upgrade to 1.6, if you have not enabled the alpha feature, then the scheduler will use the `affinity` field in PodSpec and will ignore the annotation. If you have enabled the alpha feature, then the scheduler will use the `affinity` field in PodSpec if it is present, and otherwise will...

* New alpha feature limits the number of processes running in a pod. Cluster administrators will be able to place limits by using the new kubelet command line parameter --pod-max-pids. Note that since this is a alpha feature they will need to enable the "SupportPodPidsLimit" feature. By default, we do not set any maximum limit, If an administrator wants to enable this, they should enable SupportPodPidsLimit=true in the --feature-gates= parameter to kubelet and specify the limit using the --pod-max-pids...

- If you are running the cloud-controller-manager and you have the `pvlabel.kubernetes.io` alpha Initializer enabled, you must now enable PersistentVolume labeling using the `PersistentVolumeLabel` admission controller instead. You can do this by adding `PersistentVolumeLabel` in the `--enable-admission-plugins` kube-apiserver flag.  ([#73102](https://github.com/kubernetes/kubernetes/pull/73102), [@andrewsykim](https://github.com/andrewsykim))

- PersistentVolumeLastPhaseTransitionTime feature is stable and enabled by default. ([#124969](https://github.com/kubernetes/kubernetes/pull/124969), [@RomanBednar](https://github.com/RomanBednar)) [SIG API Machinery, Apps, Storage and Testing]

### **Storage**

*   [stable] `PersistentVolume` and `PersistentVolumeClaim` objects must now have a capacity greater than zero.
*   [stable] Mutation of `PersistentVolumeSource` after creation is no longer allowed
*   [alpha] Deletion of `PersistentVolumeClaim` objects that are in use by a pod no longer permitted (if alpha feature is enabled).
*   [alpha] Container Storage Interface

### API Change

- A new IngressClass resource has been added to enable better Ingress configuration. ([#88509](https://github.com/kubernetes/kubernetes/pull/88509), [@robscott](https://github.com/robscott)) [SIG API Machinery, Apps, CLI, Network, Node and Testing]

    * `kubeadm config migrate` command of kubeadm v1.11.x
* kube-apiserver: the `Priority` admission plugin is now enabled by default when using `--enable-admission-plugins`. If using `--admission-control` to fully specify the set of admission plugins, the `Priority` admission plugin should be added if using the `PodPriority` feature, which is enabled by default in 1.11. ([#65739](https://github.com/kubernetes/kubernetes/pull/65739), [@liggitt](https://github.com/liggitt))

- EndpointSlices are now beta but not yet enabled by default. Use the EndpointSlice feature gate to enable this feature. ([#85365](https://github.com/kubernetes/kubernetes/pull/85365), [@robscott](https://github.com/robscott))