RPC.NET.Server 5.0.0-preview3

RPC.NET

Simple, lightweight RPC implementation for .NET

This documentation refers the version 5.X of the library

Name	Package
RPC.NET.Interfaces
RPC.NET.Client
RPC.NET.Server
RPC.NET-Connector

How it works

1. The client sends a HTTP POST to the server where

   • The request URI

     • Must use HTTP or HTTPS scheme
     • Identifies the remote module and method (in the query component)
     • May contain the sessionid and/or custom data (in the query component)

     For example: http://www.example.org:1986/api?module=IMyModule&method=ModuleMethod&sessionid=xXx.

   • The content-type is application/json

   • The request body is an (UTF-8) JSON stringified array that contains the method arguments. For example: ["cica", 10].

2. The type of response depends on the kind of the result:
   • If the remote method has a non Stream return value then the content-type is application/json and the response body contains the (UTF-8) JSON stringified result. The result is a wrapped object that contains the actual outcome of the method or the error description:

     {
       "Result": 12,
       "Exception": null
     }
     

     or

     {
       "Result": null,
       "Exception": {
         "TypeName": "System.Exception, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e",
         "Message": "Exception of type 'System.Exception' was thrown.",
         "Data": {}
       }
     }
     

   • If the remote method has a Stream return value (and the invocation was successful) then the content-type is application/octet-stream and the response body contains the raw data.

Server example

1. Install the RPC.NET.Server package. Since modules are stored in a IServiceCollection you may need to install the Injector.NET package as well.

2. Define an interface and implementation for your module:

   public interface ICalculator // Since clients may want to use it as well, it may be worth to put this interface into a common assembly
   {
     int Add(int a, int b);
     Task<int> AddAsync(int a, int b); // async methods also supported
     double PI { get; }
   }
   ...
   public class Calculator : ICalculator 
   {
     private readonly IRequestContext FContext;
     // You can access the request context as a dependency
     public Calculator(IRequestContext context) => FContext = context ?? throw new ArgumentNullException(nameof(context));
     public int Add(int a, int b) => a + b;
     public Task<int> AddAsync(int a, int b)
     {
       FContext.Cancellation.ThrowIfCancellationRequested();
       return Task.FromResult(a + b);
     }
     public double PI => Math.PI;
   }
   

   There are some control attributes that can be applied on (module) interface methods:

   • AliasAttribute: Specifies the alias of the method. Useful if your module has overloaded methods.

   • IgnoreAttribute: Marks the method "remotely invisible".

   • Aspects are also supported. The built-in aspects are the followings:

     • ParameterValidatorAspectAttribute:

     [ParameterValidatorAspect]
     public interface IModule
     {
       void DoSomething([NotNull, Match("cica", ParameterValidationErrorMessage = "ooops")] string arg1, [NotNull] object arg2);
       void DoSomethingElse();
       void ConditionallyValidated([NotNull(Condition = typeof(IfLoggedIn))] string arg);
     }
     
     public enum MyRoles
     {
       Anonymous = 0,
       LoggedInUser = 1
     }
     
     public class IfLoggedIn : IConditionalValidatior
     {
       public bool ShouldRun(MethodInfo containingMethod, IInjector currentScope) =>
         currentScope.Get<IRoleManager>().GetAssignedRoles(null).Equals(MyRoles.LoggedInUser);
     }
     

     The complete list of available parameter/property validators are here

     • TransactionAspectAttribute:

     [TransactionAspect]
     public interface IModule
     {
       void NonTransactional();
       [Transactional]
       void DoSomething(object arg);
       [Transactional]
       void DoSomethingFaulty();
       [Transactional(IsolationLevel = IsolationLevel.Serializable)]
       Task<int> DoSomethingAsync();
     }
     

     • RoleValidatorAspectAttribute:

     [Flags]
     public enum MyRoles
     {
       Anonymous = 0,
       User = 1,
       MayPrint = 2,
       Admin = 4
     }
     
     [RoleValidatorAspect] // to usse this aspect you have to implement and register the IRoleManager service
     public interface IModule
     {
       [RequiredRoles(MyRoles.User | MyRoles.MayPrint, MyRoles.Admin)]
       void Print();
       [RequiredRoles(MyRoles.User | MyRoles.MayPrint, MyRoles.Admin)]
       Task<string> PrintAsync();
       [RequiredRoles(MyRoles.Anonymous)]
       void Login();
       void MissingRequiredRoleAttribute(); // will throw since there is not RequiredRoles attribute
     }	 
     

     • LoggerAspectAttribute:

     [ModuleLoggerAspect]
     public interface IModule
     {
       void DoSomething(string arg1, object arg2);
       [Loggers(typeof(ExceptionLogger), typeof(StopWatchLogger))] // overrides the default loggers
       void DoSomethingElse();
     }
     // the above is a shorthand for:
     [LoggerAspect(typeof(ModuleMethodScopeLogger), typeof(ExceptionLogger), typeof(ParameterLogger), typeof(StopWatchLogger))]  // this sets the default loggers
     public interface IModule
     {
       void DoSomething(string arg1, object arg2);
       [Loggers(typeof(ExceptionLogger), typeof(StopWatchLogger))] // overrides the default loggers
       void DoSomethingElse();
     }
     

     Note that these aspects are naked

   These attributes are provided by the RPC.NET.Interfaces package.

3. Define and host your service:

   using System;
   using System.Linq;   
   using Microsoft.Extensions.Logging;
   using Solti.Utils.DI.Interfaces;
   using Solti.Utils.Rpc.Hosting;
   using Solti.Utils.Rpc.Interfaces;
   
   public class AppHost : AppHostBase
   {
     public AppHost() => Name = "Calculator";
   
     public override void OnBuildService(RpcServiceBuilder serviceBuilder) => serviceBuilder
       .ConfigureWebService(new WebServiceDescriptor
       {
         Url = "http://localhost:1986/api/",
         AllowedOrigins = new[] 
         {
           "http://localhost:1987"
         }
       })
       .ConfigureServices(services => services.Factory<ILogger>(i => ConsoleLogger.Create<AppHost>(), Lifetime.Singleton))
       .ConfigureModules(modules => modules.Register<ICalculator, Calculator>());
   }
   

4. Create the service exe:

   using System;
   using Solti.Utils.DI;
   using Solti.Utils.Rpc;
   
   class Program
   {
     static void Main(string[] args) => HostRunner.Run<AppHost>();
   }
   

5. The compiled executable can be used in several ways:

   • You can simply run it to debug your app (Ctrl-C terminates the server)
   • You can invoke it with -install to install your app as a local service (-uninstall does the opposite)
   • It can run as a local service (started by SCM) - if it was installed previously

How to listen on HTTPS (Windows only)

Requires this script to be loaded (.(".\cert.ps1"))

1. If you don't have your own, create a self-signed certificate

   Create-SelfSignedCertificate -OutDir ".\Cert" -Password "cica"
   

2. Register the certificate

   Bind-Certificate -P12Cert ".Cert\certificate.p12" -Password "cica" -IpPort "127.0.0.1:1986"
   

Client example

1. Install the RPC.NET.Client package.
2. Reference the assembly that contains the module interface you want to use.
3. Create the client:

   using Solti.Utils.Rpc;
   ...
   using var factory = new RpcClientFactory("http://127.0.0.1:1986/api/");
   ICalculator calculator = await factory.CreateClient<ICalculator>();
   try
   {
     int result = await calculator.AddAsync(1, 2);
   } catch(RpcException ex) {
     // ex.InnerException will contain the original exception
   }
   

JS client example

See here

Resources

API docs

Version history

Server boilerplate (comprehensive)

Sample server (used in tests)

Tests (remote module invocation related)

Benchmark results