Autofac error - No scope with a Tag matching 'AutofacWebRequest' is visible from the scope in which the instance was requested

Question

In one of my web applications, I have a web service that is using Autofac, the svc file is as follows:

<%@ ServiceHost Language="C#" Debug="true" 
Service="MyApp.WebServices.Contracts.Interfaces.IMyWebService, MyApp.WebServices.Contracts" 
Factory="Autofac.Integration.Wcf.AutofacServiceHostFactory, Autofac.Integration.Wcf" %>

I register the dependencies for my web service application like this:

public class IocConfig
{        
    public static void RegisterDependencies()
    {
        var builder = new ContainerBuilder();            

        //web services
        builder.RegisterType<MyWebService>().As<IMyWebService>().InstancePerLifetimeScope();

        var container = builder.Build();

        AutofacHostFactory.Container = container;            
    }
}

From another web application, I want to connect to those services also using Autofac, so I register the dependencies like:

public class IocConfig
{
    //Ioc dependencies for frontend application
    public static void RegisterDependencies()
    {
        var builder = new ContainerBuilder();

        builder.RegisterControllers(typeof(MvcApplication).Assembly);

        builder.RegisterModule<AutofacWebTypesModule>();

        builder
            .Register(c => new ChannelFactory<ISomeWebService>(
                new BasicHttpBinding(),
                new EndpointAddress("http://localhost/MyApp.WebServices/MyWebService.svc")))
            .InstancePerLifetimeScope();

        //register service proxies
        builder.Register(c => c.Resolve<ChannelFactory<IMyWebService>>().CreateChannel())
            .As<IMyWebService>()
            .UseWcfSafeRelease();

        var container = builder.Build();
        DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
    }
}

Inside one of the controllers, I do the following:

public SomeController(IMyWebService myServiceProxy) 
    {
        _myServiceProxy = myServiceProxy;

        var response =_myServiceProxy.CallSomeMethod(new Request()
        {
            EmailAddress = "[email protected]"
        });
    }

The myServiceProxy of type IMyWebService is being resolved, I see that it is a transparent proxy, but when I call the "CallSomeMethod" I get an error:

No scope with a Tag matching 'AutofacWebRequest' is visible from the scope in which the instance was requested. This generally indicates that a component registered as per-HTTP request is being requested by a SingleInstance() component (or a similar scenario.) Under the web integration always request dependencies from the DependencyResolver.Current or ILifetimeScopeProvider.RequestLifetime, never from the container itself.

What am I doing wrong here? Thanks!

Answer 1

Per the docs, WCF doesn't support per-request lifetime scope. If your service implementation is taking dependencies, you can't register them as per request.

There is an FAQ telling you how to troubleshoot this and alternatives you can use.