Support for X-Forwarded headers

Support has been added for X-Forwarded-Port and X-Forwarded-Proto.
This will enable reverse proxy servers to feed the public port
and protocol to eventstore. These values will be used in generating
URLs in responses.

src/EventStore.Core.Tests/EventStore.Core.Tests.csproj

@@ -417,6 +417,7 @@
     <Compile Include="Services\Transport\Http\PortableServer.cs" />
     <Compile Include="Services\Transport\Http\ping_controller_should.cs" />
     <Compile Include="MightyMooseIgnoreAttribute.cs" />
+    <Compile Include="Services\Transport\Http\proxy_headers.cs" />
     <Compile Include="Services\Transport\Http\speed_test.cs" />
     <Compile Include="Services\Transport\Http\uri_router_should.cs" />
     <Compile Include="Services\Transport\Tcp\ssl_connection.cs" />

src/EventStore.Core.Tests/Services/Transport/Http/proxy_headers.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Collections.Specialized;
+using EventStore.Transport.Http.EntityManagement;
+using NUnit.Framework;
+
+namespace EventStore.Core.Tests.Services.Transport.Http
+{
+    [TestFixture]
+    class proxy_headers
+    {
+        [Test]
+        public void with_no_headers_uri_is_unchanged()
+        {
+            var inputUri = new Uri("http://www.example.com:1234/path/?key=value#anchor");
+            var requestedUri =
+                HttpEntity.BuildRequestedUrl(inputUri,
+                                             new NameValueCollection());
+
+            Assert.AreEqual(inputUri, requestedUri);
+        }
+
+        [Test]
+        public void with_port_forward_header_only_port_is_changed()
+        {
+            var inputUri = new Uri("http://www.example.com:1234/path/?key=value#anchor");
+            var headers = new NameValueCollection { { "X-Forwarded-Port", "4321" } };
+            var requestedUri =
+                HttpEntity.BuildRequestedUrl(inputUri, headers);
+
+            Assert.AreEqual(new Uri("http://www.example.com:4321/path/?key=value#anchor"), requestedUri);
+        }
+
+        [Test]
+        public void non_integer_port_forward_header_is_ignored()
+        {
+            var inputUri = new Uri("http://www.example.com:1234/path/?key=value#anchor");
+            var headers = new NameValueCollection { { "X-Forwarded-Port", "abc" } };
+            var requestedUri =
+                HttpEntity.BuildRequestedUrl(inputUri, headers);
+
+            Assert.AreEqual(inputUri, requestedUri);
+        }
+
+        [Test]
+        public void with_proto_forward_header_only_scheme_is_changed()
+        {
+            var inputUri = new Uri("http://www.example.com:1234/path/?key=value#anchor");
+            var headers = new NameValueCollection { { "X-Forwarded-Proto", "https" } };
+            var requestedUri =
+                HttpEntity.BuildRequestedUrl(inputUri, headers);
+
+            Assert.AreEqual(new Uri("https://www.example.com:1234/path/?key=value#anchor"), requestedUri);
+        }
+    }
+}

src/EventStore.Core/Services/Transport/Http/Controllers/ClusterWebUIController.cs

@@ -64,7 +64,7 @@ private static void RegisterRedirectAction(IHttpService service, string fromUrl,
                         new[]
                             {
                                 new KeyValuePair<string, string>(
-                                    "Location",   new Uri(match.BaseUri, toUrl).AbsoluteUri)
+                                    "Location",   new Uri(http.HttpEntity.RequestedUrl, toUrl).AbsoluteUri)
                             }, Console.WriteLine));
         }
     }

src/EventStore.Transport.Http/EntityManagement/HttpEntity.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Specialized;
 using System.Net;
 using System.Security.Principal;
 using EventStore.Common.Utils;
@@ -19,12 +20,36 @@ public HttpEntity(HttpListenerRequest request, HttpListenerResponse response, IP
             Ensure.NotNull(request, "request");
             Ensure.NotNull(response, "response");
 
-            RequestedUrl = request.Url;
+            RequestedUrl = BuildRequestedUrl(request.Url, request.Headers);
             Request = request;
             Response = response;
             User = user;
         }
 
+        public static Uri BuildRequestedUrl(Uri requestUrl, NameValueCollection requestHeaders)
+        {
+            var uriBuilder = new UriBuilder(requestUrl);
+
+            var forwardedPortHeaderValue = requestHeaders[ProxyHeaders.XForwardedPort];
+
+            if (!string.IsNullOrEmpty(forwardedPortHeaderValue))
+            {
+                int requestPort;
+                if (Int32.TryParse(forwardedPortHeaderValue, out requestPort))
+                {
+                    uriBuilder.Port = requestPort;
+                }
+            }
+
+            var forwardedProtoHeaderValue = requestHeaders[ProxyHeaders.XForwardedProto];
+            if (!string.IsNullOrEmpty(forwardedProtoHeaderValue))
+            {
+                uriBuilder.Scheme = forwardedProtoHeaderValue;
+            }
+
+            return uriBuilder.Uri;
+        }
+
         private HttpEntity(IPrincipal user)
         {
             RequestedUrl = null;

src/EventStore.Transport.Http/EventStore.Transport.Http.csproj

@@ -68,6 +68,7 @@
     <Compile Include="ICodec.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="HttpStatusCode.cs" />
+    <Compile Include="ProxyHeaders.cs" />
     <Compile Include="Server\HttpAsyncServer.cs" />
     <Compile Include="WebRequestExtensions.cs" />
   </ItemGroup>

src/EventStore.Transport.Http/ProxyHeaders.cs

@@ -0,0 +1,14 @@
+namespace EventStore.Transport.Http
+{
+    public static class ProxyHeaders
+    {
+        public const string XForwardedPort = "X-Forwarded-Port";
+        public const string XForwardedProto = "X-Forwarded-Proto";
+    }
+
+    public static class ProxyHeaderValues
+    {
+        public const string XForwardedProtoHttp = "http";
+        public const string XForwardedProtoHttps = "https";
+    }
+}