Add websocket session identifier to listen verb websocket headers

[alex-wirebee]

Use case: Have multiple replicas of a websocket server listening for bidirectional streams, connected to from the jambonz listen verb.
A load balancer is used in front of these replicas, and in order for the load balancer to always forward a websocket session to a specific replica (header based session affinity), the websocket headers need to have an id (in this case, call_sid would probably be a good identifier) which the load balancer can map to a replica.

[davehorton]

are you specifically asking for this to be carried in an HTTP custom header ?

[alex-wirebee]

Yes, I believe that should do it since the load balancer lets me specify which header to use for identifying the session

[davehorton]

why do you care which replica a particular call session websocket connection gets routed to?

[alex-wirebee]

If the client is connected to replica A and then it connects to replica B, replica B doesn't have the state for the session so the websocket will be closed and then reopened.