Feature/#623 (#632)

* #630 only set status code if response hasnt started, otherwise exception

* #623 made {RemoteIpAddress} available as placeholder so you can do x-forwarded-for

* #623 local address different on mac, windows and linux for integration test

src/Ocelot/Headers/AddHeadersToRequest.cs

@@ -1,22 +1,29 @@
-using System.Collections.Generic;
-using System.Linq;
-using Ocelot.Configuration;
-using Ocelot.Infrastructure.Claims.Parser;
-using Ocelot.Responses;
-using System.Net.Http;
-using Microsoft.AspNetCore.Http;
-using Ocelot.Configuration.Creator;
-using Ocelot.Request.Middleware;
-
-namespace Ocelot.Headers
+namespace Ocelot.Headers
 {
+    using System.Collections.Generic;
+    using System.Linq;
+    using Infrastructure;
+    using Logging;
+    using Ocelot.Configuration;
+    using Ocelot.Infrastructure.Claims.Parser;
+    using Ocelot.Responses;
+    using Microsoft.AspNetCore.Http;
+    using Microsoft.Extensions.Primitives;
+    using Ocelot.Configuration.Creator;
+    using Ocelot.Middleware;
+    using Ocelot.Request.Middleware;
+
     public class AddHeadersToRequest : IAddHeadersToRequest
     {
         private readonly IClaimsParser _claimsParser;
+        private readonly IPlaceholders _placeholders;
+        private readonly IOcelotLogger _logger;
 
-        public AddHeadersToRequest(IClaimsParser claimsParser)
+        public AddHeadersToRequest(IClaimsParser claimsParser, IPlaceholders placeholders, IOcelotLoggerFactory factory)
         {
+            _logger = factory.CreateLogger<AddHeadersToRequest>();
             _claimsParser = claimsParser;
+            _placeholders = placeholders;
         }
 
         public Response SetHeadersOnDownstreamRequest(List<ClaimToThing> claimsToThings, IEnumerable<System.Security.Claims.Claim> claims, DownstreamRequest downstreamRequest)
@@ -46,6 +53,7 @@ namespace Ocelot.Headers
         public void SetHeadersOnDownstreamRequest(IEnumerable<AddHeader> headers, HttpContext context)
         {
             var requestHeader = context.Request.Headers;
+
             foreach (var header in headers)
             {
                 if (requestHeader.ContainsKey(header.Key))
@@ -53,7 +61,22 @@ namespace Ocelot.Headers
                     requestHeader.Remove(header.Key);
                 }
 
-                requestHeader.Add(header.Key, header.Value);
+                if (header.Value.StartsWith("{") && header.Value.EndsWith("}"))
+                {
+                    var value = _placeholders.Get(header.Value);
+
+                    if (value.IsError)
+                    {
+                        _logger.LogWarning($"Unable to add header to response {header.Key}: {header.Value}");
+                        continue;
+                    }
+
+                    requestHeader.Add(header.Key, new StringValues(value.Data));
+                }
+                else
+                {
+                    requestHeader.Add(header.Key, header.Value);
+                }
             }
         }
     }

src/Ocelot/Headers/HttpResponseHeaderReplacer.cs

@@ -1,15 +1,13 @@
-using System.Collections.Generic;
-using System.Linq;
-using Ocelot.Configuration;
-using Ocelot.Infrastructure;
-using Ocelot.Infrastructure.Extensions;
-using Ocelot.Middleware;
-using Ocelot.Middleware.Multiplexer;
-using Ocelot.Request.Middleware;
-using Ocelot.Responses;
-
 namespace Ocelot.Headers
 {
+    using System.Collections.Generic;
+    using System.Linq;
+    using Ocelot.Configuration;
+    using Ocelot.Infrastructure;
+    using Ocelot.Infrastructure.Extensions;
+    using Ocelot.Middleware;
+    using Ocelot.Responses;
+
     public class HttpResponseHeaderReplacer : IHttpResponseHeaderReplacer
     {
         private readonly IPlaceholders _placeholders;
@@ -19,8 +17,11 @@ namespace Ocelot.Headers
             _placeholders = placeholders;
         }
 
-        public Response Replace(DownstreamResponse response, List<HeaderFindAndReplace> fAndRs, DownstreamRequest request)
+        public Response Replace(DownstreamContext context, List<HeaderFindAndReplace> fAndRs)
         {
+            var response = context.DownstreamResponse;
+            var request = context.DownstreamRequest;
+
             foreach (var f in fAndRs)
             {
                 var dict = response.Headers.ToDictionary(x => x.Key);

src/Ocelot/Headers/IHttpResponseHeaderReplacer.cs

@@ -1,14 +1,12 @@
-using System.Collections.Generic;
-using Ocelot.Configuration;
-using Ocelot.Middleware;
-using Ocelot.Middleware.Multiplexer;
-using Ocelot.Request.Middleware;
-using Ocelot.Responses;
-
 namespace Ocelot.Headers
 {
+    using System.Collections.Generic;
+    using Ocelot.Configuration;
+    using Ocelot.Middleware;
+    using Ocelot.Responses;
+
     public interface IHttpResponseHeaderReplacer
     {
-        Response Replace(DownstreamResponse response, List<HeaderFindAndReplace> fAndRs, DownstreamRequest httpRequestMessage);
+        Response Replace(DownstreamContext context, List<HeaderFindAndReplace> fAndRs);
     }
 }

src/Ocelot/Headers/Middleware/HttpHeadersTransformationMiddleware.cs

@@ -45,7 +45,7 @@ namespace Ocelot.Headers.Middleware
 
             var postFAndRs = context.DownstreamReRoute.DownstreamHeadersFindAndReplace;
 
-            _postReplacer.Replace(context.DownstreamResponse, postFAndRs, context.DownstreamRequest);
+            _postReplacer.Replace(context, postFAndRs);
 
             _addHeadersToResponse.Add(context.DownstreamReRoute.AddHeadersToDownstream, context.DownstreamResponse);
         }

src/Ocelot/Infrastructure/Placeholders.cs

@@ -1,47 +1,38 @@
-using System;
-using System.Collections.Generic;
-using System.Net.Http;
-using Ocelot.Infrastructure.RequestData;
-using Ocelot.Middleware;
-using Ocelot.Request.Middleware;
-using Ocelot.Responses;
-
 namespace Ocelot.Infrastructure
 {
+    using System;
+    using System.Collections.Generic;
+    using Microsoft.AspNetCore.Http;
+    using Ocelot.Infrastructure.RequestData;
+    using Ocelot.Middleware;
+    using Ocelot.Request.Middleware;
+    using Ocelot.Responses;
+
     public class Placeholders : IPlaceholders
     {
         private readonly Dictionary<string, Func<Response<string>>> _placeholders;
         private readonly Dictionary<string, Func<DownstreamRequest, string>> _requestPlaceholders;
         private readonly IBaseUrlFinder _finder;
         private readonly IRequestScopedDataRepository _repo;
+        private readonly IHttpContextAccessor _httpContextAccessor;
 
-        public Placeholders(IBaseUrlFinder finder, IRequestScopedDataRepository repo)
+        public Placeholders(IBaseUrlFinder finder, IRequestScopedDataRepository repo, IHttpContextAccessor httpContextAccessor)
         {
             _repo = repo;
+            _httpContextAccessor = httpContextAccessor;
             _finder = finder;
-            _placeholders = new Dictionary<string, Func<Response<string>>>();
-            _placeholders.Add("{BaseUrl}", () => new OkResponse<string>(_finder.Find()));
-            _placeholders.Add("{TraceId}", () => {
-                var traceId = _repo.Get<string>("TraceId");
-                if(traceId.IsError)
-                {
-                    return new ErrorResponse<string>(traceId.Errors);
-                }
+            _placeholders = new Dictionary<string, Func<Response<string>>>
+            {
+                { "{BaseUrl}", GetBaseUrl() },
+                { "{TraceId}", GetTraceId() },
+                { "{RemoteIpAddress}", GetRemoteIpAddress() }
 
-                return new OkResponse<string>(traceId.Data);
-            });
+            };
 
-            _requestPlaceholders = new Dictionary<string, Func<DownstreamRequest, string>>();
-            _requestPlaceholders.Add("{DownstreamBaseUrl}", x => {
-                var downstreamUrl = $"{x.Scheme}://{x.Host}";
-
-                if(x.Port != 80 && x.Port != 443)
-                {
-                    downstreamUrl = $"{downstreamUrl}:{x.Port}";
-                }
-
-                return $"{downstreamUrl}/";
-            });
+            _requestPlaceholders = new Dictionary<string, Func<DownstreamRequest, string>>
+            {
+                { "{DownstreamBaseUrl}", GetDownstreamBaseUrl() }
+            };
         }
 
         public Response<string> Get(string key)
@@ -67,5 +58,56 @@ namespace Ocelot.Infrastructure
 
             return new ErrorResponse<string>(new CouldNotFindPlaceholderError(key));
         }
+
+        private Func<Response<string>> GetRemoteIpAddress()
+        {
+            return () =>
+            {
+                // this can blow up so adding try catch and return error
+                try
+                {
+                    var remoteIdAddress = _httpContextAccessor.HttpContext.Connection.RemoteIpAddress.ToString();
+                    return new OkResponse<string>(remoteIdAddress);
+                }
+                catch (Exception e)
+                {
+                    return new ErrorResponse<string>(new CouldNotFindPlaceholderError("{RemoteIpAddress}"));
+                }
+            };
+        }
+
+        private Func<DownstreamRequest, string> GetDownstreamBaseUrl()
+        {
+            return x =>
+            {
+                var downstreamUrl = $"{x.Scheme}://{x.Host}";
+
+                if (x.Port != 80 && x.Port != 443)
+                {
+                    downstreamUrl = $"{downstreamUrl}:{x.Port}";
+                }
+
+                return $"{downstreamUrl}/";
+            };
+        }
+
+        private Func<Response<string>> GetTraceId()
+        {
+            return () =>
+            {
+                var traceId = _repo.Get<string>("TraceId");
+                if (traceId.IsError)
+                {
+                    return new ErrorResponse<string>(traceId.Errors);
+                }
+
+                return new OkResponse<string>(traceId.Data);
+            };
+        }
+
+        private Func<Response<string>> GetBaseUrl()
+        {
+            return () => new OkResponse<string>(_finder.Find());
+        }
     }
 }