- Promote CSIMigrationOpenStack to Beta (off by default since it requires installation of the OpenStack Cinder CSI Driver. The in-tree AWS OpenStack Cinder driver "kubernetes.io/cinder" was deprecated in 1.16 and will be removed in 1.20. Users should enable CSIMigration + CSIMigrationOpenStack features and install the OpenStack Cinder CSI Driver (https://github.com/kubernetes/cloud-provider-openstack) to avoid disruption to existing Pod and PVC objects at that time....

* fixes a bug around using the Global config ElbSecurityGroup where Kuberentes would modify the passed in Security Group. ([#49805](https://github.com/kubernetes/kubernetes/pull/49805), [@nbutton23](https://github.com/nbutton23))
* Updates Cinder AttachDisk operation to be more reliable by delegating Detaches to volume manager. ([#50042](https://github.com/kubernetes/kubernetes/pull/50042), [@jingxu97](https://github.com/jingxu97))

 - OpenStack Cinder CSI migration is on by default, Clinder CSI driver must be installed on clusters on OpenStack for Cinder volumes to work. ([#98538](https://github.com/kubernetes/kubernetes/pull/98538), [@dims](https://github.com/dims)) [SIG Storage]

- Added Custom Resource support to `kubectl autoscale` ([#72678](https://github.com/kubernetes/kubernetes/pull/72678), [@rmohr](https://github.com/rmohr))
- Cinder volume limit can now be configured from node too ([#74542](https://github.com/kubernetes/kubernetes/pull/74542), [@gnufied](https://github.com/gnufied))

* Make volume usage metrics available for Cinder ([#62668](https://github.com/kubernetes/kubernetes/pull/62668), [@zetaab](https://github.com/zetaab))

### **OpenStack**

*   OpenStack Cinder support has been improved:
    *   Cinder version detection now works properly. ([#53115](https://github.com/kubernetes/kubernetes/pull/53115),[ @FengyunPan](https://github.com/FengyunPan))

  * Dynamic Provisioning of PersistentVolumes: Kubernetes previously required all
volumes to be manually provisioned by a cluster administrator before use. With
this feature, volume plugins that support it (GCE PD, AWS EBS, and Cinder) can
automatically provision a PersistentVolume to bind to an unfulfilled
PersistentVolumeClaim.
  * Run multiple schedulers in parallel, e.g. one or more custom schedulers

- OpenStack Cinder CSI migration is now GA and switched on by default, Cinder CSI driver must be installed on clusters on OpenStack for Cinder volumes to work (has been since v1.21). ([#107462](https://github.com/kubernetes/kubernetes/pull/107462), [@dims](https://github.com/dims))

  when the corresponding csi driver was installed:
  - `awsElasticBlockStore` for `ebs.csi.aws.com`
  - `azureDisk` for `disk.csi.azure.com`
  - `gcePersistentDisk` for `pd.csi.storage.googleapis.com`
  - `cinder` for `cinder.csi.openstack.org`
  - `csi`
  However it was still enforced using a limit in CSINode objects. ([#126924](https://github.com/kubernetes/kubernetes/pull/126924), [@carlory](https://github.com/carlory))

- Fix filtering of server status.
- Fix resizing PVC of Cinder volume.
- Disable load balancer configuration if it is not defined in cloud config.
- Add support for node shutdown taint.

The external provider includes all of the above with the additional fixes and features:
- Fix bug to prevent allocation of existing floating IP.
- Fix Cinder authentication bug when OS_DOMAIN_NAME not specified.