Important Update: The originally presented code only works if the service is defined in the same assembly which hosts the service (because the name="" attribute in <service> may not contain the assembly name of the service). See at the end of the article for a slightly different version which works in all cases --- but which involves adding a second config file.
As WCF has reached RC1 stage, I find myself cleaning up a few bits of older WCF code. While playing around with it, I always found myself having to start more and more ServiceHosts for different configurations. The following snippet iterates over all <service> entries in configuration/system.serviceModel and opens a ServiceHost for each of them.
Update: Added code to close all services.
using System;
using System.Collections.Generic;
using System.Reflection;
using System.Configuration;
using System.ServiceModel.Configuration;
using System.ServiceModel;
public class ServiceHostGroup
{
static List<ServiceHost> _hosts = new List<ServiceHost>();
private static void OpenHost(Type t)
{
ServiceHost hst = new ServiceHost(t);
hst.Open();
_hosts.Add(hst);
}
public static void StartAllConfiguredServices()
{
Configuration conf =
ConfigurationManager.OpenExeConfiguration(Assembly.GetEntryAssembly().Location);
ServiceModelSectionGroup svcmod =
(ServiceModelSectionGroup)conf.GetSectionGroup("system.serviceModel");
foreach (ServiceElement el in svcmod.Services.Services)
{
Type svcType = Type.GetType(el.Name);
if (svcType == null)
throw new Exception("Invalid Service Type " + el.Name + " in configuration file.");
OpenHost(svcType);
}
}
public static void CloseAllServices()
{
foreach (ServiceHost hst in _hosts)
{
hst.Close();
}
}
}
As mentioned above, I have in the meantime learned (after long and hard fighting against the "this service has no non-metadata endpoints"-exception), that the name="" attribute in <service> must not contain an assembly name. I guess I have been too used to Remoting configuration files after all ;-). To still get dynamic service configuration without code changes, I've added a second configuration file called services.xml and changed the code for ServiceHostGroup to the following:
Services.XML:
<configuredServices>
<service type="ServiceImplementation.ArticleService, ServiceImplementation" />
</configuredServices>
ServiceHostBase.cs:
using System;
using System.Collections.Generic;
using System.Reflection;
using System.Configuration;
using System.ServiceModel.Configuration;
using System.ServiceModel;
using System.Xml;
using System.Xml.Serialization;
using System.IO;
public class ServiceHostGroup
{
static List<ServiceHost> _hosts = new List<ServiceHost>();
private static void OpenHost(Type t)
{
ServiceHost hst = new ServiceHost(t);
Type ty = hst.Description.ServiceType;
hst.Open();
_hosts.Add(hst);
}
public static void StartAllConfiguredServices()
{
ConfiguredServices services = ConfiguredServices.LoadFromFile("services.xml");
foreach (ConfiguredService svc in services.Services)
{
Type svcType = Type.GetType(svc.Type);
if (svcType == null) throw new Exception("Invalid Service Type " + svc.Type + " in configuration file.");
OpenHost(svcType);
}
}
public static void CloseAllServices()
{
foreach (ServiceHost hst in _hosts)
{
hst.Close();
}
}
}
[XmlRoot("configuredServices")]
public class ConfiguredServices
{
public static ConfiguredServices LoadFromFile(string filename)
{
if (!File.Exists(filename)) return new ConfiguredServices();
XmlSerializer ser = new XmlSerializer(typeof(ConfiguredServices));
using (FileStream fs = File.OpenRead(filename))
{
return (ConfiguredServices) ser.Deserialize(fs);
}
}
[XmlElement("service", typeof(ConfiguredService))]
public List<ConfiguredService> Services = new List<ConfiguredService>();
}
public class ConfiguredService
{
[XmlAttribute("type")]
public string Type;
}