* Added warning msg for `kubectl get` ([#28352](https://github.com/kubernetes/kubernetes/pull/28352), [@vefimova](https://github.com/vefimova))
* Removed support for HPA in extensions client. ([#30504](https://github.com/kubernetes/kubernetes/pull/30504), [@piosz](https://github.com/piosz))
* Implement DisruptionController. ([#25921](https://github.com/kubernetes/kubernetes/pull/25921), [@mml](https://github.com/mml))

**Who is affected?**

Only Kubernetes 1.5.0-1.5.4 installations that do all of the following:
* Enable the PodSecurityPolicy API (which is not enabled by default):
  * `--runtime-config=extensions/v1beta1/podsecuritypolicy=true`
* Enable the PodSecurityPolicy admission plugin (which is not enabled by default):
  * `--admission-control=...,PodSecurityPolicy,...`

- The following feature gates for volume expansion GA features have now been removed and must no longer be referenced in `--feature-gates` flags: `ExpandCSIVolumes`, `ExpandInUsePersistentVolumes`, `ExpandPersistentVolumes` ([#113942](https://github.com/kubernetes/kubernetes/pull/113942), [@meng...

### Network

In v1.9 SIG Network has implemented alpha support for IPv6, and alpha support for CoreDNS as a drop-in replacement for kube-dns. Additionally, SIG Network has begun the deprecation process for the extensions/v1beta1 NetworkPolicy API in favor of the networking.k8s.io/v1 equivalent.

### Node

 * Kotlin code. In this class, nothing is publicly visible (nor exposed indirectly through a
 * publicly visible subclass), and I doubt any of our current or future Kotlin extensions for the
 * package will refer to the class. Plus, @ParametricNullness is only a temporary workaround,
 * anyway, so we just need to get by without the annotations here until Kotlin better understands

 * Kotlin code. In this class, nothing is publicly visible (nor exposed indirectly through a
 * publicly visible subclass), and I doubt any of our current or future Kotlin extensions for the
 * package will refer to the class. Plus, @ParametricNullness is only a temporary workaround,
 * anyway, so we just need to get by without the annotations here until Kotlin better understands

- Implement support for recovering from volume expansion failures ([#106154](https://github.com/kubernetes/kubernetes/pull/106154), [@gnufied](https://github.com/gnufied)) [SIG API Machinery, Apps and Storage]

* Volume expansion is now considered Beta. ([#64288](https://github.com/kubernetes/kubernetes/pull/64288), [@gnufied](https://github.com/gnufied))

      this.threshold = newTable.length() * 3 / 4; // 0.75
      if (!map.customWeigher() && this.threshold == maxSegmentWeight) {
        // prevent spurious expansion before eviction
        this.threshold++;
      }
      this.table = newTable;
    }

    @GuardedBy("this")
    ReferenceEntry<K, V> newEntry(K key, int hash, @CheckForNull ReferenceEntry<K, V> next) {

### CLI

This release includes a change to [kubectl get and describe to work better with extensions](https://github.com/kubernetes/enhancements/issues/515), as the server, rather than the client, returns this information for a smoother user experience.

### Network