mqtt client_id support

[kbudde]

According to the documentation https://www.rabbitmq.com/access-control.html#topic-authorisation the client_id can be used in topic authorisation.

Is the client_id currently provided to the web server? If not I think it makes sense to add this information to at least user_path and topic_path requests.

Internal (default) authorisation backend supports variable expansion in permission patterns. Three variables are supported: username, vhost, and client_id. Note that client_id only applies to MQTT. For example, if tonyg is the connected user, the permission ^{username}-. is expanded to ^tonyg-.

[michaelklishin]

There's already an issue for that https://github.com/rabbitmq/rabbitmq-mqtt/issues/152.

[michaelklishin]

No, that's not really a duplicate but this plugin doesn't control what kind of context it gets, so I'll file a separate one in the MQTT plugin.

[acogoluegnes]

@kbudde Have you tried actually? Because client_id should be propagated to the HTTP backend, at least for topic authorization.

The MQTT plugin adds the client_id to the context for topic authorization: https://github.com/rabbitmq/rabbitmq-mqtt/blob/d92fa2aed107147e4bab1ae8cc0dc5dddfcc4b75/src/rabbit_mqtt_processor.erl#L855-L863

The HTTP backend plugin propagates it to the actual backend: https://github.com/rabbitmq/rabbitmq-auth-backend-http/blob/96d66359c2f122fd5f05f958a18050e601bb53de/src/rabbit_auth_backend_http.erl#L75-L84

[kbudde]

Hi,

the client_id is there for topic authorization. It is as well included in the header of the user request with a different name (var_map..)