#603 return 502 on HttpRequestException

src/Ocelot/Errors/OcelotErrorCode.cs

@@ -39,6 +39,7 @@
         CannotAddPlaceholderError = 34,
         CannotRemovePlaceholderError = 35,
         QuotaExceededError = 36,
-        RequestCanceled = 37,
+        RequestCanceled = 37,
+        ConnectionToDownstreamServiceError = 38,
     }
 }

src/Ocelot/Requester/ConnectionToDownstreamServiceError.cs

@@ -0,0 +1,13 @@
+using Ocelot.Errors;
+using System;
+
+namespace Ocelot.Requester
+{
+    class ConnectionToDownstreamServiceError : Error
+    {
+        public ConnectionToDownstreamServiceError(Exception exception)
+            : base($"Error connecting to downstream service, exception: {exception}", OcelotErrorCode.ConnectionToDownstreamServiceError)
+        {
+        }
+    }
+}

src/Ocelot/Requester/HttpExeptionToErrorMapper.cs

@@ -4,6 +4,8 @@ namespace Ocelot.Requester
     using Microsoft.Extensions.DependencyInjection;
     using System;
     using System.Collections.Generic;
+    using System.Net.Http;
+    using System.Net.Sockets;
 
     public class HttpExeptionToErrorMapper : IExceptionToErrorMapper
     {
@@ -28,6 +30,11 @@ namespace Ocelot.Requester
                 return new RequestCanceledError(exception.Message);
             }
 
+            if (type == typeof(HttpRequestException))
+            {
+                return new ConnectionToDownstreamServiceError(exception);
+            }
+
             return new UnableToCompleteRequestError(exception);
         }
     }

src/Ocelot/Responder/ErrorsToHttpStatusCodeMapper.cs

@@ -38,11 +38,16 @@ namespace Ocelot.Responder
             if (errors.Any(e => e.Code == OcelotErrorCode.UnableToFindDownstreamRouteError))
             {
                 return 404;
+            }
+
+            if (errors.Any(e => e.Code == OcelotErrorCode.ConnectionToDownstreamServiceError))
+            {
+                return 502;
             }
 
             if (errors.Any(e => e.Code == OcelotErrorCode.UnableToCompleteRequestError))
             {
-                return 502;
+                return 500;
             }
 
             return 404;