Controller for transport of MQTT data between the browser (client) and server.

This controller accepts Websocket connections and out-of-band HTTP POSTs.

The HTTP POSTs must have a valid ticket. See m_mqtt_ticket on how to obtain such a ticket and more information about tickets.

The Websocket connection is a normal MQTT transport over Websocket.

For the authentication the Websocket accepts two methods:

• Cookie authentication with z.auth cookie, see controller_authentication.
• Username and password in the MQTT connect