我正在尝试使用多个进程内owin侦听器。每个控制器都应该具有一组不同的控制器，它们可以由不同的控制器处理相同的路径。例如
localhost:1234/api/app/test应解析为ControllerA
localhost:5678/api/app/test应解析为ControllerB
控制器a，在owin主机1中，具有路径属性
[Route("api/app/test")]
控制器b，在owin主机2中，具有路径属性
[Route("api/app/{*path}")]
用于将请求转发给其他owin主机。
我们正在使用Autofac进行依赖注入。路由通过属性路由进行配置。 autofac需要一行，例如
builder.RegisterApiControllers(typeof(ControllerA).Assembly)
我们的OWIN配置包含：
var config = ConfigureWebApi();
// Configure Autofac
config.DependencyResolver = new AutofacWebApiDependencyResolver(container);
app.UseAutofacMiddleware(container);
app.UseAutofacWebApi(config);
app.UseWebApi(config);
但是，在启动两个侦听器时，我需要包含两个程序集以进行控制器解析。这会导致“重复路由”异常：
Multiple controller types were found that match the URL. This can happen if attribute routes on multiple controllers match the requested URL.\r\n\r\nThe request has found the following matching controller types: \r\nLib1.Controllers.ControllerA\r\nLib2.Controllers.ControllerB"
在单独的进程中运行OWIN侦听器时，没有问题。
我还尝试使用多个DI容器，每个OWIN监听器一个，但与Web Api 2冲突，因为它需要设置GlobalConfiguration.Configuration.DependencyResolver。这与多个DI容器的概念相冲突。
有人可以指导我如何配置这样的设置吗？
答案 0 :(得分：3)
OWIN环境并自定义HttpControllerSelector 使用OWIN管道，您可以将有关请求的信息传递给自定义HttpControllerSelector。这使您可以选择使用哪些控制器来匹配哪些路径。
当然，这说起来容易做起来难。 WebAPI在路由方面的内部工作方式不是很透明 - source code通常是该领域的最佳文档。
我无法使HttpControllerSelector完全正常工作，因此CustomHttpActionSelector中有一个丑陋的解决方法。如果你需要做的就是将请求从一个主机转发到另一个主机，这可能仍然是足够的。
最终结果是：
GET到http://localhost:1234/api/app/test返回“HellofromAController”（直接调用AController）
GET到http://localhost:5678/api/app/test返回“（FromBController）：\”HellofromAController \“”（调用BController，将请求转发给AController）
我保留了日志记录代码，以防它有用，但它与解决方案无关。
所以不用多说：
<强> CustomHttpControllerSelector.cs ：
使用特定于端口的OWIN env变量ApiControllersAssembly来过滤控制器。
public sealed class CustomHttpControllerSelector : DefaultHttpControllerSelector
{
private static readonly ILog Logger;
static CustomHttpControllerSelector()
{
Logger = LogProvider.GetCurrentClassLogger();
}
public CustomHttpControllerSelector(HttpConfiguration configuration) : base(configuration)
{
}
public override HttpControllerDescriptor SelectController(HttpRequestMessage request)
{
var apiControllerAssembly = request.GetOwinEnvironment()["ApiControllersAssembly"].ToString();
Logger.Debug($"{nameof(CustomHttpControllerSelector)}: {{{nameof(apiControllerAssembly)}: {apiControllerAssembly}}}");
var routeData = request.GetRouteData();
var routeCollectionRoute = routeData.Route as IReadOnlyCollection<IHttpRoute>;
var newRoutes = new List<IHttpRoute>();
var newRouteCollectionRoute = new RouteCollectionRoute();
foreach (var route in routeCollectionRoute)
{
var filteredDataTokens = FilterDataTokens(route, apiControllerAssembly);
if (filteredDataTokens.Count == 2)
{
var newRoute = new HttpRoute(route.RouteTemplate, (HttpRouteValueDictionary)route.Defaults, (HttpRouteValueDictionary)route.Constraints, filteredDataTokens);
newRoutes.Add(newRoute);
}
}
var newRouteDataValues = new HttpRouteValueDictionary();
foreach (var routeDataKvp in routeData.Values)
{
var newRouteDataCollection = new List<IHttpRouteData>();
var routeDataCollection = routeDataKvp.Value as IEnumerable<IHttpRouteData>;
if (routeDataCollection != null)
{
foreach (var innerRouteData in routeDataCollection)
{
var filteredDataTokens = FilterDataTokens(innerRouteData.Route, apiControllerAssembly);
if (filteredDataTokens.Count == 2)
{
var newInnerRoute = new HttpRoute(innerRouteData.Route.RouteTemplate, (HttpRouteValueDictionary)innerRouteData.Route.Defaults, (HttpRouteValueDictionary)innerRouteData.Route.Constraints, filteredDataTokens);
var newInnerRouteData = new HttpRouteData(newInnerRoute, (HttpRouteValueDictionary)innerRouteData.Values);
newRouteDataCollection.Add(newInnerRouteData);
}
}
newRouteDataValues.Add(routeDataKvp.Key, newRouteDataCollection);
}
else
{
newRouteDataValues.Add(routeDataKvp.Key, routeDataKvp.Value);
}
HttpRouteData newRouteData;
if (newRoutes.Count > 1)
{
newRouteCollectionRoute.EnsureInitialized(() => newRoutes);
newRouteData = new HttpRouteData(newRouteCollectionRoute, newRouteDataValues);
}
else
{
newRouteData = new HttpRouteData(newRoutes[0], newRouteDataValues);
}
request.SetRouteData(newRouteData);
}
var controllerDescriptor = base.SelectController(request);
return controllerDescriptor;
}
private static HttpRouteValueDictionary FilterDataTokens(IHttpRoute route, string apiControllerAssembly)
{
var newDataTokens = new HttpRouteValueDictionary();
foreach (var dataToken in route.DataTokens)
{
var actionDescriptors = dataToken.Value as IEnumerable<HttpActionDescriptor>;
if (actionDescriptors != null)
{
var newActionDescriptors = new List<HttpActionDescriptor>();
foreach (var actionDescriptor in actionDescriptors)
{
if (actionDescriptor.ControllerDescriptor.ControllerType.Assembly.FullName == apiControllerAssembly)
{
newActionDescriptors.Add(actionDescriptor);
}
}
if (newActionDescriptors.Count > 0)
{
newDataTokens.Add(dataToken.Key, newActionDescriptors.ToArray());
}
}
else
{
newDataTokens.Add(dataToken.Key, dataToken.Value);
}
}
return newDataTokens;
}
}
<强> CustomHttpActionSelector.cs ：
您不应该需要CustomHttpActionSelector，这仅适用于解决与BController的ActionDescriptors有关的问题。只要BController只有一个方法，它就可以工作，否则你需要实现一些特定于路由的逻辑。
public sealed class CustomHttpActionSelector : ApiControllerActionSelector
{
private static readonly ILog Logger;
static CustomHttpActionSelector()
{
Logger = LogProvider.GetCurrentClassLogger();
}
public override HttpActionDescriptor SelectAction(HttpControllerContext controllerContext)
{
try
{
var actionDescriptor = base.SelectAction(controllerContext);
return actionDescriptor;
}
catch (Exception ex)
{
Logger.WarnException(ex.Message, ex);
IDictionary<string, object> dataTokens;
var route = controllerContext.Request.GetRouteData().Route;
var routeCollectionRoute = route as IReadOnlyCollection<IHttpRoute>;
if (routeCollectionRoute != null)
{
dataTokens = routeCollectionRoute
.Select(r => r.DataTokens)
.SelectMany(dt => dt)
.ToDictionary(kvp => kvp.Key, kvp => kvp.Value);
}
else
{
dataTokens = route.DataTokens;
}
var actionDescriptors = dataTokens
.Select(dt => dt.Value)
.Where(dt => dt is IEnumerable<HttpActionDescriptor>)
.Cast<IEnumerable<HttpActionDescriptor>>()
.SelectMany(r => r)
.ToList();
return actionDescriptors.FirstOrDefault();
}
}
}
<强> Program.cs的：
internal class Program
{
private static readonly ILog Logger;
static Program()
{
Log.Logger = new LoggerConfiguration()
.WriteTo
.LiterateConsole()
.MinimumLevel.Is(LogEventLevel.Verbose)
.CreateLogger();
Logger = LogProvider.GetCurrentClassLogger();
}
internal static void Main(string[] args)
{
var builder = new ContainerBuilder();
builder.RegisterModule(new LogRequestModule());
builder.RegisterApiControllers(typeof(AController).Assembly);
builder.RegisterApiControllers(typeof(BController).Assembly);
var container = builder.Build();
var config = GetHttpConfig();
config.DependencyResolver = new AutofacWebApiDependencyResolver(container);
var options = new StartOptions();
options.Urls.Add("http://localhost:1234");
options.Urls.Add("http://localhost:5678");
var listener = WebApp.Start(options, app =>
{
app.Use((ctx, next) =>
{
if (ctx.Request.LocalPort.HasValue)
{
var port = ctx.Request.LocalPort.Value;
string apiControllersAssemblyName = null;
if (port == 1234)
{
apiControllersAssemblyName = typeof(AController).Assembly.FullName;
}
else if (port == 5678)
{
apiControllersAssemblyName = typeof(BController).Assembly.FullName;
}
ctx.Set("ApiControllersAssembly", apiControllersAssemblyName);
Logger.Info($"{nameof(WebApp)}: Port = {port}, ApiControllersAssembly = {apiControllersAssemblyName}");
}
return next();
});
app.UseAutofacMiddleware(container);
app.UseAutofacWebApi(config);
app.UseWebApi(config);
});
Logger.Info(@"Press [Enter] to exit");
Console.ReadLine();
listener.Dispose(); ;
}
private static HttpConfiguration GetHttpConfig()
{
var config = new HttpConfiguration();
config.MapHttpAttributeRoutes();
config.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;
config.Services.Add(typeof(IExceptionLogger), new LogProviderExceptionLogger());
config.Formatters.Remove(config.Formatters.XmlFormatter);
config.Services.Replace(typeof(IHttpControllerSelector), new CustomHttpControllerSelector(config));
config.Services.Replace(typeof(IHttpActionSelector), new CustomHttpActionSelector());
var traceSource = new TraceSource("LibLog") { Switch = { Level = SourceLevels.All } };
traceSource.Listeners.Add(new LibLogTraceListener());
var diag = config.EnableSystemDiagnosticsTracing();
diag.IsVerbose = false;
diag.TraceSource = traceSource;
return config;
}
}
<强> LIBA \控制器\ AController.cs ：
[RoutePrefix("api/app")]
public class AController : ApiController
{
private static readonly ILog Logger;
static AController()
{
Logger = LogProvider.GetCurrentClassLogger();
Logger.Debug($"{nameof(AController)}: Static Constructor");
}
public AController()
{
Logger.Debug($"{nameof(AController)}: Constructor");
}
[HttpGet, Route("test")]
public async Task<IHttpActionResult> Get()
{
Logger.Debug($"{nameof(AController)}: Get()");
return Ok($"Hello from {nameof(AController)}");
}
}
<强> LibB \控制器\ BController.cs ：
[RoutePrefix("api/app")]
public class BController : ApiController
{
private static readonly ILog Logger;
static BController()
{
Logger = LogProvider.GetCurrentClassLogger();
Logger.Debug($"{nameof(BController)}: Static Constructor");
}
public BController()
{
Logger.Debug($"{nameof(BController)}: Constructor");
}
[HttpGet, Route("{*path}")]
public async Task<IHttpActionResult> Get([FromUri] string path)
{
if (path == null)
{
path = Request.RequestUri.PathAndQuery.Split(new[] {"api/app/"}, StringSplitOptions.RemoveEmptyEntries)[1];
}
Logger.Debug($"{nameof(BController)}: Get({path})");
using (var client = new HttpClient {BaseAddress = new Uri("http://localhost:1234/api/app/")})
{
var result = await client.GetAsync(path);
var content = await result.Content.ReadAsStringAsync();
return Ok($"(From {nameof(BController)}): {content}");
}
}
}
当我有更多时间的时候，我可能会再次参与其中。
如果你取得任何进展，请告诉我！