alethic / cogito.aspnetcore.servicemodel

WCF support for ASP.Net Core

Cogito.AspNetCore.ServiceModel

WCF support for ASP.Net Core

Provides middleware for ASP.Net Core for wiring up a WCF ServiceHost instance and directing requests to it. This is a bit more complicated than just establishing a binding and dispatcher.

public void ConfigureServices(IServiceCollection services)
{
    services.AddServiceModel();
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    app.UseServiceHost<MathService>("/math");
}

I've done a few things internally that are sort of weird.

Each invocation of UseServiceHost starts up a ServiceHost instance. This service host is configured by default with bindings that establish a AspNetCoreTransport. The transport generates ReplyChannels which sets up an inbound delivery queue based on the binding properties. As ASP.Net Core requests arrive, they are dispatched into the router where the hunt for a queue that they should be put into. The ReplyChannelListener dequeues these requests and enters them into the WCF pipeline. Reply messages likewise write back to the originating ASP.Net core Response.

Internally a non-standard ListenURI is set up for each invocation of UseServiceHost. These each get a "Router ID", which is a GUID that idenfies the target ServiceHost instance. This can probably go away now that I can get access to the server addresses of Kestrel and such. The main problem here is the branching paths in ASP.Net are not known until a request traverses them. So, I can't determine the path of the service until a request comes in. WCF makes this all very hard.

This lets us use the existing ServiceHost class. And thus eventually piggyback on existing ServiceHost extensions: like Autofac integration. And it keeps the dispatch/contract discovery stuff in WCF.

The ServiceHost is automatically configured with service metadata endpoints at ?wsdl, and a help page, like most standard WCF services. A channel dispatcher message inspector is used to rewrite router URLs in the response.