Customising instantiation of WCF web service - c#

I have a WCF RESTful service that I want to integration test so need to create an instance of the service locally within the test with a reference to a client channel that I can call. I can do this, however the code I'm using will only call the Services default parameterless constructor as below
_serviceHost = new WebServiceHost(typeof(UserService), baseAddress);
var binding = new WebHttpBinding();
_serviceHost.AddServiceEndpoint(typeof(Interface.IUserService), binding, address.Uri);
_serviceHost.Open();
In my UserService class, I want to inject a dependency into it for the data repository, as so
public UserService(IUserDataRepository userRepository)
{
_userRepository = userRepository;
}
How can I adapt the first lot of code so that I can create and self host my WCF REST service with an IDataRepository object that I create (Mock) in the test class?

Well, I think you can use the same approach as you have for production environment. I might be wrong but you must already have your custom ServiceHost and ServiceHostFactory. If not please take a look at this article Using Instance Provider and ServiceHostFactory to Construct the Service. You want to read through steps steps 1-3. You will need to derive from WebServiceHost to implement your own one. Then your code will look like that:
_serviceHost = new YourCustomServiceHost(typeof(UserService), baseAddress);
Hope it helps!

Related

.NET Core + WCF integration with DI Problem

I have an problem to declare dependency injection. I have to declare a WCF service and I did it like this:
services.AddTransient<IService, ServiceClient>();
As I will need to work with the WCF header I need to add a behavior to check the headers. Normally I would do it like this:
var client = new ServiceClient();
client.Endpoint.Behaviors.Add( new HeaderInspectionBehavior());
But I can't do it that way because I'm getting the IService injected in the constructor.
I tried to do it this way:
var client = new ServiceClient();
client.Endpoint.Behaviors.Add(new HeaderInspectionBehavior());
services.AddTransient<IService, ServiceClient>(sp => client);
But it didn't work, in the second WCF call it changes the state to "FAULT" or "CLOSED".
Does anyone know of another way to do this?
Based in this i found a solution that looks like this:
ServiceClient Config(IServiceProvider _) => new ServiceClient(..., ...);
services.AddTransient<IService, ServiceClient>(Config);
It's work for me.

Create multiple instances of same dependency w/ different configuration

I have an application (IJobInit) that uses a list from JSON settings to create multiple instances of a class (IJob). This class does some work using two other dependencies, IInputClient and IOutputClient. It uses M.Extensions.DependencyInjection to create a container which is handed off to AutoFac to create an IContainer.
IJobInit(IContainer container)
I would like IInputClient to be configured different for each instance of IJob. Speficially, I'd like to pass in a secret for it to use. The result would be:
IInputClient(HttpClient client)
where HttpClient is configured using ConfigureHttpClient such that IJob does not know that it is pre-authenticated. This would also be suitable:
IInputClient(ISecretProvider secretsProvider, string secretName)
The end result is three instances of IJob with IInputClient configured differently.
IJob(IInputClient inputClient1, IOutputClient outputClient)
IJob(IInputClient inputClient2, IOutputClient outputClient)
IJob(IInputClient inputClient3, IOutputClient outputClient)
How do I achieve this? I was looking at Autofac scopes but those controlwhen an instance is created without any control over its configuration (unless I missed it).
A colleague suggested that I could host each instance of IJob in its own process with its own configuration which is possible but I'm trying to host all the jobs in a single Azure Function and use the list in config to create the inner jobs.
Thanks!
I'm not totally happy with this solution but it works for now.
private async Task<IInputClient> GetClientAsync(string secretId)
{
HttpClient httpClient = this.httpClientFactory.CreateClient();
string secret = await this.secretsProvider.GetSecretAsync(secretId);
httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.ASCII.GetBytes(string.Concat(":", secret))));
return this.scope.Resolve<IInputClient>(new TypedParameter(typeof(HttpClient), httpClient));
}

WCF/REST Logging

I was wondering if someone could show me how to log a simple request/response from my wcf rest service.
I am self hosting with a console application on the localmachine:
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string baseAddress = "http://" + Environment.MachineName + ":8000/Service";
ServiceHost host = new ServiceHost(typeof(RawDataService), new Uri(baseAddress));
WebHttpBinding binding = new WebHttpBinding();
//binding.Security.Mode = WebHttpSecurityMode.Transport;
host.AddServiceEndpoint(typeof(IReceiveData), new WebHttpBinding(), "").Behaviors.Add(new WebHttpBehavior());
host.Open();
Console.WriteLine("Host opened");
Console.ReadLine();
}
}
}
I was really hoping all that would be required is something added to the hosting console app. I tryed following this but it was abit confusing http://blogs.msdn.com/b/carlosfigueira/archive/2011/04/19/wcf-extensibility-message-inspectors.aspx
Just to note I am not using any app.config or web.config files.
EDIT:
I also cannot use any third party products for this.
Are you talking about logging for debugging purposes or for monitoring in a live service?
If you are debugging you can just switch on WCF tracing. It will produce a very comprehensive log and there is a good free tool for viewing the log that comes as part of the Windows SDK - I presume when you say you can't use third party product it doesn't include built-in .Net and Windows SDK features...
http://msdn.microsoft.com/en-us/library/ms733025.aspx
A common way to handle this is with Aspect-Oriented Programming (AOP) using the Castle Dynamic Proxy library. The idea is that you can decorate/proxy your service implementation with a dynamic class that intercepts every single method called on your service. No matter what method is called on your service, they'll be "intercepted" by your proxy and sent to a single method where you can log what you want and then you can finish the original call. Here's a quick sample of what that looks like:
public class LoggingInterceptor : IInterceptor
{
// No matter what service method is called, it's funneled through here.
public void Intercept(IInvocation call)
{
MyLogger.Info("Starting call: " + call.Method.Name);
// Actually invoke whatever method was originally called
call.Proceed();
MyLogger.Info("Finished call: " + call.Method.Name);
}
}
Now you need to create a proxy of your service class that uses this interceptor for all of its method calls. You can pretty up and abstract as necessary, but this is the basic jist:
using Castle.DynamicProxy;
...
// Create your service object and then create a dynamic proxy of the object
// that will inject your logging interceptor logic.
ProxyGenerator generator = new ProxyGenerator();
RawDataService service = new RawDataService();
RawDataService proxy = generator.CreateClassProxyWithTarget<RawDataService>(
service,
new LoggingInterceptor());
// Register your proxy object, not the raw service w/ WCF
WebServiceHost host = new WebServiceHost(proxy, new Uri(baseAddress));
... rest of your code as it was ...
Now any call made to your RawDataService will go through the Intercept() method first and when it calls Proceed() your actual implemented service logic will happen. You can update the interceptor to handle exceptions, include a StopWatch and log parameters as needed but that's the basic idea.
My example shows you the brute force way of setting this up. The "cleaner" solution would be to use IoC to create your service instance/proxy but this should get your code doing what you want right now. For further reading, here's a link to the Castle project's tutorial on using its AOP hooks:

Custom Membership provider with dependency injection - how to test

This is similar to Dependency Injection with Custom Membership Provider, but the responses there don't solve the issue for me.
I have a custom membership provider which has a dependency to a repository class. ASP.NET will always instantiate this using the parameter-less constructor, so to resolve the dependency to the repository I have a kind of service locator method ... my ctor looks like this:
public CustomMembershipProvider()
{
_userRepository = AppStart_NinjectMVC3.Resolve<IUserRepository>();
}
And that Resolve method looks like this..
public static T Resolve<T>() where T : class
{
return _kernel.Get<T>();
}
This works fine when I run the web app, because _kernel is correctly setup. However, I need to test the methods on my membership provider.. So when my test code tries to invoke the methods on membership provider it will instantiate a new membership provider class with the paramter-less ctor, which errors because _kernel is not setup.
What I want to do is somehow inject my FakeUserRepository class instead, but how can I achieve that?
I think I have a work round for this...
I've added a ctor to the membership provider which accepts a repository instance, and then I've manually instantiated my membership provider in my test class like this:
var prov = new CableSenseMembershipProvider(new FakeUserRepository());
var config = new NameValueCollection();
config.Add("applicationName", "ddd");
config.Add("name", "CustomMembershipProvider");
config.Add("requiresQuestionAndAnswer", "false");
config.Add("requiresUniqueEmail", "false");
prov.Initialize(config["name"], config);
Once I've dont this I can then invoke that instance and not worry about the parameter-less ctor being called.
As an aside, you still need to add the membership section to your test project app.config or it wont work - which is somewhat confusing!
Why not extract everything out of your custom membership provider into an implementation class and instantiate that class via the service locator then pass all your calls through to that? The implementation class can then be unit-testable and the ugly Membership stuff can be 'right by inspection'.

Create WCF service client with specified address without specifying configuration name

Is there a way to create an instance of a WCF service client in C# with a specified endpoint address without specifying a configuration name?
By default, clients have these constructors:
public ServiceClient()
public ServiceClient(string endpointConfigurationName)
public ServiceClient(string endpointConfigurationName, string remoteAddress)
Obviously, there is a default configuration, because of the first constructor. What I want is to only specify the 2nd parameter of the final constructor. Right now, I'm struggling through reading the configuration elements of using ConfigurationManager to figure it out, but it seems horribly cumbersome. Is there a cleaner way?
I prefer not to use the endpoint configuration in the .config file. I normally do something like this:
BasicHttpBinding basicbinding = new BasicHttpBinding();
basicbinding.SendTimeout = TIMEOUT;
basicbinding.OpenTimeout = TIMEOUT;
ServiceClient client = new ServiceClient(basicbinding, new EndpointAddress(new Uri("http://xxxxx")));
Your generated client should also have a constructor that looks like this:
public ServiceClient(
System.ServiceModel.Channels.Binding binding,
System.ServiceModel.EndpointAddress remoteAddress)
: base(binding, remoteAddress) {
}
You can call this one without an endpoint configuration.
If you want to actually just want to call a service without having to know everything there is to know about WCF services and configuration handling, in C # you can just do...
String url = "http:\\somehost:someport\\pathToSomeService";
EndpointAddress address = new EndpointAddress(url);
Binding binding = new BasicHttpBinding();
YourClient client = new YourClient(binding, address);
// Call your client methods
client.SomeMethod(parm1, parm2);
The above assumes you generated a service reference and does not require configuration information to exist anywhere, not in the generated service reference, not in the DLL and not in the executable. No configuration. None.
I use the above in a true standalone service proxy dll. It is standalone in the truest sense of the word as it is completely configurable with no dependence on the calling executable to provide anything.
Well, you could use the default constructor, but then you'd have to manually program in all of the configuration settings. By specifying the configuration name, the service client will automatically load the configuration in from the .config file, all you need to know is which configuration to use (you can have multiple, e.g. one for HTTP and another for Net.Tcp). The remoteAddress, of course, just tells WCF where to make the connection.
If you are having trouble configuring the client settings themselves, make sure you're using the WCF Service Configuration tool. It works for both the service config as well as the client config.

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