Configure multiple instances of rebus for a single process with autofac

Question

I ran into a situation where my application need to send messages to 2 queues that are in two different virtual hosts in rabbit and read from one of them. Moving those 2 queues into one virtual host (which is the perfect solution) not possible. Therefore, I need to run 2 rebus instances in a single process.

I'm using autofac for dependency injection. Could you please redirect me to some resource explaining how I can setup multiple instances in rebus with autofac in a single process?

thank you very much!

Answer 1

You should configure the bus instance, that you intend to use to send/publish messages on the other vhost, as a one-way client, which you then access through a dedicated service you create for this purpose.

Something along the lines of this:

public class OtherVhostBusClient : IDisposable
{
    readonly IBus _bus;

    public OtherVhostBusClient(string amqpConnectionString)
    {
        _bus = Configure.With(new BuiltinHandlerActivator())
            .Transport(t => {
                t.UseRabbitMqAsOneWayClient(amqpConnectionString);
            })
            .Start();
    }

    public Task Publish(object e) => _bus.Publish(e);

    public void Dispose() => _bus.Dispose();
}

If you then configure OtherVhostBusClient as a singleton in your Autofac container, you can have it injected and use it to publish stuff on the other vhost.

This way, you are essentially treating this as a "foreign network" of sorts, implementing the integration with it as you would any other type of integration between "networks" (could be Rebus on any other transport, HTTP, etc.)

I hope that makes sense :)