Making delivery mandatory

So far, the back office team at CC has been relying only on emails to interact with individual drivers. CC recently added the RabbitMQ-powered system discussed in Chapter 3, Sending Messages to Multiple Taxi Drivers, allowing the back office to send information messages to all drivers. They now want to explore the possibility of sending messages to individual drivers from the back office service. Furthermore, if possible, CC would like drivers who do not have an inbox queue set up on RabbitMQ to get the message emailed to them immediately.

In terms of messaging architecture, this is a known territory—the exact same model was put in place in Chapter 2, Creating a Taxi Application, for client-to-taxi messages, as illustrated in the following diagram:

Fig 4.6: The back office team will use the taxi direct exchange for direct messages to drivers

A direct exchange is used. The only difference is that, unlike the main application, the back office will not...