Allow Setting the Multiattach Property

volume multiattach status is set to False by default during volume creation. User can only specify the volume shareable during volume creation time using –allow-multiattach.
There are scenarios where user might need to allow the volume to be shared later during volume lifecycle.
Today there is no way we can set the volume multiattach property after volume creation.

We propose a change in the Volume Update REST API to allow updating the multiattach property.

Additionally a cinder cli command set-multiattach which can be used to edit the volume multiattach property.

to add multiattach option like this.
 $ cinder set-multiattach [volume_uuid] [True|False]