Add a debug info page

Author: DamianEdwards

src/Benchmarks/DebugInfoPageMiddleware.cs

@@ -0,0 +1,75 @@
+// Copyright (c) .NET Foundation. All rights reserved. 
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information. 
+
+using System;
+using System.Threading.Tasks;
+using Microsoft.AspNet.Builder;
+using Microsoft.AspNet.Hosting;
+using Microsoft.AspNet.Http;
+using Microsoft.Extensions.PlatformAbstractions;
+
+namespace Benchmarks
+{
+    public class DebugInfoPageMiddleware
+    {
+        private static readonly PathString _path = new PathString("/debug");
+#if DEBUG
+        private static readonly string _configurationName = "Debug";
+#elif RELEASE
+        private static readonly string _configurationName = "Release";
+#else
+        private static readonly string _configurationName = "";
+#endif
+
+        private readonly IApplicationEnvironment _appEnv;
+        private readonly IHostingEnvironment _hostingEnv;
+        private readonly RequestDelegate _next;
+
+        public DebugInfoPageMiddleware(RequestDelegate next, IHostingEnvironment hostingEnv, IApplicationEnvironment appEnv)
+        {
+            _next = next;
+            _hostingEnv = hostingEnv;
+            _appEnv = appEnv;
+        }
+
+        public async Task Invoke(HttpContext httpContext)
+        {
+            // We check Ordinal explicitly first because it's faster than OrdinalIgnoreCase
+            if (httpContext.Request.Path.StartsWithSegments(_path, StringComparison.Ordinal) ||
+                httpContext.Request.Path.StartsWithSegments(_path, StringComparison.OrdinalIgnoreCase))
+            {
+                httpContext.Response.ContentType = "text/html";
+
+                await httpContext.Response.WriteAsync("<h1>Application Information</h1>");
+                await httpContext.Response.WriteAsync("<ul>");
+
+                await httpContext.Response.WriteAsync($"<li>Environment: {_hostingEnv.EnvironmentName}</li>");
+                await httpContext.Response.WriteAsync($"<li>Framework: {_appEnv.RuntimeFramework.FullName}</li>");
+                await httpContext.Response.WriteAsync($"<li>Configuration: {_configurationName}</li>");
+                await httpContext.Response.WriteAsync($"<li>Server: {_hostingEnv.Configuration["server"]}</li>");
+                await httpContext.Response.WriteAsync($"<li>Server URLs: {_hostingEnv.Configuration["server.urls"]}</li>");
+
+                await httpContext.Response.WriteAsync($"<li>Server features:<ol>");
+                foreach (var feature in httpContext.Features)
+                {
+                    await httpContext.Response.WriteAsync($"<li>{feature.Key.Name}</li>");
+                }
+                await httpContext.Response.WriteAsync($"</ol></li>");
+
+                await httpContext.Response.WriteAsync("</ul>");
+
+                return;
+            }
+
+            await _next(httpContext);
+        }
+    }
+
+    public static class DebugInfoPageMiddlewareExtensions
+    {
+        public static IApplicationBuilder UseDebugInfoPage(this IApplicationBuilder builder)
+        {
+            return builder.UseMiddleware<DebugInfoPageMiddleware>();
+        }
+    }
+}

src/Benchmarks/Startup.cs

@@ -99,6 +99,8 @@ public void Configure(IApplicationBuilder app)
                 Console.WriteLine("Static file tests enabled");
             }
 
+            app.UseDebugInfoPage();
+
             app.Run(context => context.Response.WriteAsync("Try /plaintext instead"));
         }