• I as a user want to get nova notifications from the 18.0 deployment, from a separate Notifications bus not colocated with either of RPC buses.
• I as a user want to be able to provide a message bus to be used for the notification.
  • The deployment engine should support having a single message bus for all cells.

We should discuss the CRD interface as keystone- and barbican-operator uses a generic interface for notification transport_url configuration already. They don't take a RabbitMqCluster name but take a Secret name only and expecting a transport_url field in the Secret. This interface potentially allows other than rabbit based driver to be configured (e.g. kafka)

Stretched Goals

• The deployment engine should support having different message buses per cell
• The deployment engine should support reusing the RPC message bus for notifications