How can you programatically add mappings to UnicastBusConfig?

I would like to be able to add subscriptions to additional message types living on potentially different servers to my application at runtime. What I'm trying to achieve is a Monitoring application where I can add/remove subscriptions at runtime. Is this possible? How do I get a reference to the current UnicastBus mappings?

Here is what I'm doing so far, but I believe this will overwrite any mappings currently in existence.

MessageEndpointMappingCollection mappings = new MessageEndpointMappingCollection();
mappings.Add(new MessageEndpointMapping()
{
    Messages = m.MessageType.ToString(),
    Endpoint = m.QueueName
});

IComponentConfig<UnicastBusConfig> busConfig = config.Configurer.ConfigureComponent<UnicastBusConfig>(ComponentCallModelEnum.None);
busCo开发者_高级运维nfig.ConfigureProperty(u => u.MessageEndpointMappings, mappings);

Yves used this code in his Azure samples (to be found in NSB samples collection)

using NServiceBus.Config;
using NServiceBus.Config.ConfigurationSource;

namespace OrderService
{
    class ConfigOverride : IProvideConfiguration<UnicastBusConfig>
    {
        public UnicastBusConfig GetConfiguration()
        {
            return new UnicastBusConfig
            {
                MessageEndpointMappings = new MessageEndpointMappingCollection
                {
                    new MessageEndpointMapping { Messages="MyMessages", Endpoint="orderserviceinputqueue" }
                }
            };
        }
    }
}

The best way to approach this would be to implement IConfigurationSource and provide your own configuration. Then you could cherry pick what you would like to load from the config file (if anything) and what you would like to specify yourself at runtime.

I would reflect the DefaultConfigurationSource class or refer to this gist for guidance.

In a project, I am currently involved with, we are doing some content-based routing to dynamically subscribed/unsubscribed agents by keeping track of them in our own routing table.

We have wrapped the IBus in a decorator (by using Windsor's support of decorators, as described <plug>here</plug>), that sees if the message implements a special IRoutableMessage interface, that allows the decorator to route the message by explicitly specifying the destination endpoint via bus.Send(destinationEndpoint).

This was a little bit complex to get right, and I would recommend going with NServiceBus' built-in routing as far as possible. But is is possible to explicitly route messages to any endpoint.

If you are looking into monitoring, check out the NSBManager repository. This takes the opposite approach and lets the endpoints register with the manager.