Ninject, WCF & Auto Discovery

Question

I can't seem to get these 3 working together.

I narrowed it down to a very simple service with 1 method:

[System.ServiceModel.ServiceContract]
public interface Icontract
{
    [System.ServiceModel.OperationContract]
    void Ping();
}

public class contract : Icontract
{
    public void Ping()
    { }
}

I have a factory that looks like this:

public class ServiceFactory
{
    private readonly IKernel _kernel;

    public ServiceFactory(IKernel kernel)
    {
        _kernel = kernel;
    }

    public NinjectServiceHost<T> GetService<T>()
    {
        return _kernel.Get<NinjectServiceHost<T>>();
    }
}

If I create the service like so...

_tmp = new ServiceHost(typeof(ConsoleApplication1.contract));
_tmp.Open();

...Discovery works just fine. However if I use the factory like so...

_tmp = _factory.GetService<ConsoleApplication1.contract>();
_tmp.Open();

...the service isn't discoverable anymore. Everything else about the service works as expected.

Anyone had any joy getting Discovery working this way, or is there something I'm doing wrong?

score 1 · Answer 1 · answered Oct 22 '14 at 09:50

It is a bug in Ninject.Extensions.Wcf.NinjectServiceBehavior class. Just create your own NinjectServiceBehaviorFixed class derived from IServiceBehavior interface with following method:

public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
{
    foreach (EndpointDispatcher endpointDispatcher in serviceHostBase.ChannelDispatchers.OfType<ChannelDispatcher>().SelectMany(channelDispatcher => (IEnumerable<EndpointDispatcher>) channelDispatcher.Endpoints))
    {
        if (endpointDispatcher.DispatchRuntime.InstanceProvider == null)
        {
            endpointDispatcher.DispatchRuntime.InstanceProvider = _instanceProviderFactory(serviceDescription.ServiceType);
            endpointDispatcher.DispatchRuntime.MessageInspectors.Add(_requestScopeCleanUp);
        }
   }
}

Add to your NinjectModule code:

Unbind<IServiceBehavior>();
Bind<IServiceBehavior>().To<NinjectServiceBehaviorFixed>();

In ApplyDispatchBehavior method we just added check if endpointDispatcher.DispatchRuntime.InstanceProvider is null because WS-Discovery creates new endpoints with defined InstanceProvider which should not be overwritten

I'm not in a position to test this anymore, but it sounds convincing — Simon Halsey, Oct 22 '14 at 11:33

score -1 · Answer 2 · answered Jul 05 '12 at 18:20

-1

Where are you setting up your bindings? Somewhere in your code you'll need to initialize the kernel with a ServiceModule like this:

_kernel = new StandardKernel(new YourNinjectModule());

And then in the module code:

public class YourNinjectModule: NinjectModule
{
    /// <summary>
    /// Loads the module into the kernel.
    /// </summary>
    public override void Load()
    {
        // ===========================================================
        //
        // Bind dependency injection.
        // Add entries in here for any new services or repositories.
        //
        // ===========================================================

        this.Bind<Icontract>().To<contract>();
    }
}

answered Jul 05 '12 at 18:20

Garrett Vlieger

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I am aware of this. The binding are configured correctly. The service works as expected. The discovery does not however. – Simon Halsey Jul 08 '12 at 00:36
I ask because I'm curious what your bindings are. You're requesting the concrete class (`contract`) versus the interface (`Icontract`). Normally you would use `Get`. – Garrett Vlieger Jul 08 '12 at 14:55
Normally you would. However, ServiceHost & therefore NinjectServiceHost only accept concrete classes. If you specify `Icontract` when you call the factory method you get an error to that effect. – Simon Halsey Jul 09 '12 at 16:27

Ninject, WCF & Auto Discovery

2 Answers2