ProxyKit RoutingHandler

Introduction

RoutingMessageHandler is an HttpMessageHandler that will route requests to another handler based on the origin the handler is registered against. It's primary use case is to be using in acceptance / integration testing with multiple ASP.NET Core applications via TestServer.

Typical scenarios include:

• Use a single HttpClient in acceptance/integration tests when issuing requests to two or more independent applications:

  

• Providing a handler to a service that needs to make calls to one or more other services:

  

• Combined with ProxyKit to test the behaviour of your system with two instances of your application behind a reverse proxy / load balancer:

  

Example

Install the NuGet package:

dotnet package add ProxyKit.RoutingHandler

This example creates two TestServer, registers them with an origin each and shows how a request from HttpClient is routed to the respective TestServer:

var routingHandler = new RoutingMessageHandler();

// Create the two Test Servers
var fooWebHostBuilder = WebHost.CreateDefaultBuilder<FooStartup>(Array.Empty<string>());
var fooTestServer = new TestServer(fooWebHostBuilder);

var barWebHostBuilder = WebHost.CreateDefaultBuilder<BarStartup>(Array.Empty<string>());
var barTestServer = new TestServer(barWebHostBuilder);

// Register the test servers against their respective origins
routingHandler.AddHandler("http://foo", fooTestServer.CreateHandler());
routingHandler.AddHandler("http://bar", barTestServer.CreateHandler());

// Configure your HttpClient with the routing handler
var client = new HttpClient(routingHandler);

// Requests to specific origins should be routed to the correct TestServer
var fooResponse = await client.GetAsync("http://foo");
(await fooResponse.Content.ReadAsStringAsync()).ShouldBe("foo");

var barResponse = await client.GetAsync("http://bar");
(await barResponse.Content.ReadAsStringAsync()).ShouldBe("bar");

How to build

The build requires Docker to ensure portability with CI.

On Windows:

.\build.cmd

On Linux:

./build.sh

To build without docker, .NET Core SDK 3.1 is required.

On Windows:

.\build-local.cmd

On Linux:

./build-local.sh

Contributing / Feedback / Questions

Any ideas for features, bugs or questions, please create an issue. Pull requests gratefully accepted but please create an issue for discussion first.

I can be reached on twitter at @randompunter

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