What is the proper way to Host dozens of WCF Services in a single Windows Service?

Question

I've been tasked with moving over dozens of WCF Services to a single Windows Service. I've created a Windows Service using the Windows Service template and added the the following code to ServiceHostController:

public partial class ServiceHostController : ServiceBase
{
    private List<ServiceHost> serviceHosts;

    public ServiceHostController()
    {
        InitializeComponent();
        this.ServiceName = "WCFServices";
        this.CanStop = true;
        this.AutoLog = true;
    }

    protected override void OnStart(string[] args)
    {
        if (serviceHosts != null)
        {
            foreach (var service in serviceHosts)
            {
                service.Close();
            }
        }

        InitializeServices();
        foreach (var service in serviceHosts)
        {
            service.Open();
        }
    }

    protected override void OnStop()
    {
        if (serviceHosts != null)
        {
            foreach (var service in serviceHosts)
            {
                service.Close();
            }
            serviceHosts.Close(); = null;
        }

        foreach (var service in serviceHosts)
        {
            service.Close();
        }
    }

    private void InitializeServices()
    {
        serviceHosts = new List<ServiceHost>()
        {
            new ServiceHost(typeof(WCFService1)),
            new ServiceHost(typeof(WCFService2)),
            // add dozens of services here
        };
    }
}

Besides not following the Do not repeat yourself rule here (actual code is different), is this how I should be hosting these WCF services in the Windows Service code?

Answer 1

Hans, you got everything right, But I will replace your InitializeServices(); with following code. It is pseudo code so you need to replace the bits :)

1) Configure your endpoints in app.config

2) Get your Service types from your Service project\assembly

  Dictionary<Type, Type> mappings = new Dictionary<Type,Type>();

   foreach (Type t in MyServiceAssembly.GetTypes())
  {
    if (t.GetInterfaces().Length > 0)
    {
      foreach (Type ti in t.GetInterfaces())

        {
          if (mapping.ContainsKey(ti))
            System.Diagnostics.Debug.WriteLine("Class {0} implements more than one interface {1}", t.FullName, ti.FullName);
          else
            mapping.Add(ti, t);

          // System.Diagnostics.Debug.WriteLine("Class {0} implements {1}", t.FullName, ti.FullName);
        }
    }
  }

4) If you want control end points from app.config Now iterate over your end points and get corresponding service implementation then create your hosts

//read your endpoints in your service startup

 List<ServiceHost> serviceHosts = new List<ServiceHost>();

     ServicesSection servicesSection = (ServicesSection)WebConfigurationManager.GetSection("system.serviceModel/services");  

    for(int i = 0;i<servicesSection.Services.Count;i++)
    {
    ServiceEndpointElement endpoint = servicesSection.Services[i].Endpoints[0];  
    string url = string.Format("net.tcp://{0}:{1}/YouNameSpace_service_Name_From_EndPoint/{2}.svc","YourHost","YourPort");
      ServiceHost serviceHost = new ServiceHost(mappings[endpoint.Contract] , new Uri(url));

              serviceHost.Open();

              mServiceHosts.Add(serviceHost);
    }

5) If you do not want to control end points from app.config then iterate over your mapping list.

//do this in your service startup

 List<ServiceHost> serviceHosts = new List<ServiceHost>();

     foreach(type t in mappings.Keys)
    {
            string url = string.Format("net.tcp://{0}:{1}/YouNameSpace_{2}.svc","YourHost","YourPort",t.name);
      ServiceHost serviceHost = new ServiceHost(mappings[t] , new Uri(url));

              serviceHost.Open();

              mServiceHosts.Add(serviceHost);
    }