## Introduction to 1.9.0

Kubernetes version 1.9 includes new features and enhancements, as well as fixes to identified issues. The release notes contain a brief overview of the important changes introduced in this release. The content is organized by Special Interest Group ([SIG](https://github.com/kubernetes/community/blob/master/sig-list.md)).

### Other (Cleanup or Flake)

- When retrieving event resources, the reportingController and reportingInstance fields in the event will contain values. ([#120067](https://github.com/kubernetes/kubernetes/pull/120067), [@HirazawaUi](https://github.com/HirazawaUi)) [SIG Instrumentation]

## Dependencies

### Added
_Nothing has changed._

  The default value is "Cluster". ([#96600](https://github.com/kubernetes/kubernetes/pull/96600), [@maplain](https://github.com/maplain)) [SIG API Machinery, Apps and Network]
- PodDisruptionBudget API objects can now contain conditions in status. ([#98127](https://github.com/kubernetes/kubernetes/pull/98127), [@mortent](https://github.com/mortent)) [SIG API Machinery, Apps, Auth, CLI, Cloud Provider, Cluster Lifecycle and Instrumentation]

* Azure VMSS: support VM names to contain the `_` character ([#63526](https://github.com/kubernetes/kubernetes/pull/63526), [@djsly](https://github.com/djsly))

tabular output for API resources via a new mime-type `application/json;as=Table;v=v1alpha1;g=meta.k8s.io`.  The returned object (if the server supports it) will be of type `meta.k8s.io/v1alpha1` with `Table`, and contain column and row information related to the resource.  Each row will contain information about the resource - by default it will be the object metadata, but callers can add the `?includeObject=Object` query parameter and receive the full object.  In the future kubectl will use this to...

- EndpointSlice should not contain endpoints for terminating pods ([#89056](https://github.com/kubernetes/kubernetes/pull/89056), [@andrewsykim](https://github.com/andrewsykim)) [SIG Apps and Network]

- When retrieving event resources, the `reportingController` and `reportingInstance` fields in the event will contain values. ([#116506](https://github.com/kubernetes/kubernetes/pull/116506), [@HirazawaUi](https://github.com/HirazawaUi)) [SIG API Machinery and Instrumentation]

- Improvements were made to `kubeadm reset` related to cleaning  etcd and notifying the user about the state of iptables.
- kubeadm commands now print warnings if input YAML documents contain unknown or duplicate fields.
- kubeadm now properly recognizes Docker 18.09.0 and newer, but still treats 18.06 as the default supported version.

  - `spec.usages` is now required, may not contain duplicate values, and must only contain known usages
  - `status.conditions` may not contain duplicate types
  - `status.conditions[*].status` is now required

- CRD deep copies should no longer contain shallow copies of `JSONSchemaProps.XValidations`. ([#107956](https://github.com/kubernetes/kubernetes/pull/107956), [@benluddy](https://github.com/benluddy))