Send broadcast message with rabbitmq reactive messaging

[iompo]

I'm trying to send a broadcast message using the rabbitmq reactive library. I tried to follow the documentation and define an incoming broadcast channel, but the setting seems to be ignored.
Looking at the RabbitMQ publish/subscriber documentation broadcasting a message requires temporary queue with random names or names auto-generated from the server.
Quarkus requires the queue name to be specified, so what is the suggested way to define a temporary queue?

[quarkus-bot[bot]]

/cc @cescoffier (reactive-messaging), @ozangunalp (reactive-messaging)

[ozangunalp]

The broadcast config for an incoming channel in reactive messaging corresponds to how consumed messages are dispatched to different channels.

For a rabbitmq pub/sub setup you'd need to publish to a fanout exchange and bind consumer queues to that exchange.

[ozangunalp]

If we follow the example from the RabbitMQ tutorial you linked,
for producing to logs exchange:
mp.messaging.outgoing.sink.exchange.name=logs
mp.messaging.outgoing.sink.exchange.type=fanout
and in each of your consumers:
mp.messaging.incoming.in.queue.name=(server.auto)
mp.messaging.incoming.in.exchange.name=logs
mp.messaging.incoming.in.exchange.type=fanout

The declaration and binding will be done automatically. With (server.auto) for queue name declared queue will have a generated name by the broker

[iompo]

thanks! I couldn't find that (server.auto) anywhere

[ozangunalp]

I realize that it is not documented. And also not coherent with the default exchange value that is "". We align those two.