Issue using AutofacWebApiDependencyResolver with OWIN and WebAPI 2.1 - autofac

Question

I can't seem to use the DependencyResolver in my OAuthAuthorizationServerProvider.
DependencyResolver.Current
returns the MVC one which I don't use, and
GlobalConfiguration.Configuration.DependencyResolver.GetService(typeof(IXXX))
throws the following 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.
Any ideas if I am doing something wrong or I simply can't use a dependency where I'm trying?
This is what my Startup.Auth.cs looks like:
var config = new HttpConfiguration();
config.MapHttpAttributeRoutes();
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional }
);
config.SuppressDefaultHostAuthentication();
config.Filters.Add(new HostAuthenticationFilter(OAuthDefaults.AuthenticationType));
var builder = new ContainerBuilder();
builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
builder.RegisterType<XXX>().As<IXXX>().InstancePerRequest();
var container = builder.Build();
//I've tried both approached here!
GlobalConfiguration.Configuration.DependencyResolver = new AutofacWebApiDependencyResolver(container);
config.DependencyResolver = new AutofacWebApiDependencyResolver(container);
app.UseAutofacMiddleware(container);
app.UseAutofacWebApi(webApiConfig);
app.UseWebApi(webApiConfig);
And this is my OAuth provider code:
public class SimpleAuthorizationServerProvider : OAuthAuthorizationServerProvider
{
public SimpleAuthorizationServerProvider(string publicClientId)
{
if (publicClientId == null)
throw new ArgumentNullException("publicClientId");
_publicClientId = publicClientId;
}
public IXXX XXX
{
get { return (IXXX)(_xxx??GlobalConfiguration.Configuration.DependencyResolver.GetService(typeof(IXXX))); }
set { _xxx= value; }
}
public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
{
//Dependency IXXX used here
}
private readonly string _publicClientId;
private IXXX _xxx;
}

Answer 1

You can use OwinContext.GetAutofacLifetimeScope()
See the nuget package:
http://alexmg.com/owin-support-for-the-web-api-2-and-mvc-5-integrations-in-autofac/

Answer 2

Funnily enough I'm working through a similar problem at the minute and using the following OSS library to achieve this: https://github.com/DotNetDoodle/DotNetDoodle.Owin.Dependencies
This is an IoC container adapter for OWIN middleware, which puts a request level container into the environment dictionary of the OWIN middleware. The container can then be accessed from within your OWIN middleware implementation from which per-request scoped services can be resolved.
This is taken from the documentation from the github repository:
public override async Task Invoke(IOwinContext context)
{
IServiceProvider requestContainer = context.Environment.GetRequestContainer();
IRepository repository = requestContainer.GetService(typeof(IRepository)) as IRepository;
// use repos
}
The following additional links may be useful for you:
A gist discussing this issue: https://gist.github.com/tugberkugurlu/9054704. Specifically this comment: https://gist.github.com/tugberkugurlu/9054704#comment-1172998
The blog entry relating to the DotNetDoodle.Owin.Dependencies library: http://www.tugberkugurlu.com/archive/owin-dependencies--an-ioc-container-adapter-into-owin-pipeline
Hope some of this may be of help to you.