Support Multiple Hosts for a Route

docs/docfx/articles/authn-authz.md

@@ -21,7 +21,7 @@ Example:
         "ClusterId": "cluster1",
         "AuthorizationPolicy": "customPolicy",
         "Match": {
-          "Host": "localhost"
+          "Hosts": "localhost"
         },
       }
     ],

docs/docfx/articles/getting_started.md

@@ -106,15 +106,15 @@ You can find out more about the available configuration options by looking at [P
         "ClusterId": "cluster1",
         "Match": {
           "Methods": [ "GET", "POST" ],
-          "Host": "localhost",
+          "Hosts": [ "localhost" ],
           "Path": "/app1/"
         }
       },
       {
         "RouteId": "route2",
         "ClusterId": "cluster2",
         "Match": {
-          "Host": "localhost"
+          "Hosts": [ "localhost" ]
         }
       }
     ],

docs/docfx/articles/transforms.md

@@ -43,7 +43,7 @@ Here is an example of common transforms:
         "RouteId": "route1",
         "ClusterId": "cluster1",
         "Match": {
-          "Host": "localhost"
+          "Hosts": [ "localhost" ]
         },
         "Transforms": [
           { "PathPrefix": "/apis" },

samples/ReverseProxy.Sample/appsettings.json

@@ -53,7 +53,7 @@
         "ClusterId": "cluster1",
         "Match": {
           "Methods": [ "GET", "POST" ],
-          "Host": "localhost",
+          "Hosts": [ "localhost" ],
           "Path": "/api/{plugin}/stuff/{*remainder}"
         },
         "Transforms": [
@@ -64,7 +64,7 @@
         "RouteId": "route2",
         "ClusterId": "cluster2",
         "Match": {
-          "Host": "localhost"
+          "Hosts": [ "localhost" ]
         },
         "Transforms": [
           {

src/ReverseProxy/Abstractions/RouteDiscovery/Contract/ProxyMatch.cs

@@ -19,7 +19,7 @@ public class ProxyMatch : IDeepCloneable<ProxyMatch>
         /// <summary>
         /// Only match requests with the given Host header.
         /// </summary>
-        public string Host { get; set; }
+        public IReadOnlyList<string> Hosts { get; set; }
 
         /// <summary>
         /// Only match requests with the given Path pattern.
@@ -43,7 +43,7 @@ ProxyMatch IDeepCloneable<ProxyMatch>.DeepClone()
             return new ProxyMatch()
             {
                 Methods = Methods?.ToArray(),
-                Host = Host,
+                Hosts = Hosts?.ToArray(),
                 Path = Path,
                 // Headers = Headers.DeepClone(); // TODO:
             };

src/ReverseProxy/Service/Config/DynamicConfigBuilder.cs

@@ -153,7 +153,7 @@ private async Task<IList<ParsedRoute>> GetRoutesAsync(IConfigErrorReporter error
                 {
                     RouteId = route.RouteId,
                     Methods = route.Match.Methods,
-                    Host = route.Match.Host,
+                    Hosts = route.Match.Hosts,
                     Path = route.Match.Path,
                     Priority = route.Priority,
                     ClusterId = route.ClusterId,

src/ReverseProxy/Service/Config/RuleParsing/RouteValidator.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Authorization;
@@ -73,13 +74,13 @@ public async Task<bool> ValidateRouteAsync(ParsedRoute route, IConfigErrorReport
                 success = false;
             }
 
-            if (string.IsNullOrEmpty(route.Host) && string.IsNullOrEmpty(route.Path))
+            if ((route.Hosts == null || route.Hosts.Count == 0 || route.Hosts.Any(host => string.IsNullOrEmpty(host))) && string.IsNullOrEmpty(route.Path))
             {
-                errorReporter.ReportError(ConfigErrors.ParsedRouteRuleHasNoMatchers, route.RouteId, $"Route requires {nameof(route.Host)} or {nameof(route.Path)} specified. Set the Path to `/{{**catchall}}` to match all requests.");
+                errorReporter.ReportError(ConfigErrors.ParsedRouteRuleHasNoMatchers, route.RouteId, $"Route requires {nameof(route.Hosts)} or {nameof(route.Path)} specified. Set the Path to `/{{**catchall}}` to match all requests.");
                 success = false;
             }
 
-            success &= ValidateHost(route.Host, route.RouteId, errorReporter);
+            success &= ValidateHost(route.Hosts, route.RouteId, errorReporter);
             success &= ValidatePath(route.Path, route.RouteId, errorReporter);
             success &= ValidateMethods(route.Methods, route.RouteId, errorReporter);
             success &= _transformBuilder.Validate(route.Transforms, route.RouteId, errorReporter);
@@ -89,18 +90,21 @@ public async Task<bool> ValidateRouteAsync(ParsedRoute route, IConfigErrorReport
             return success;
         }
 
-        private static bool ValidateHost(string host, string routeId, IConfigErrorReporter errorReporter)
+        private static bool ValidateHost(IReadOnlyList<string> hosts, string routeId, IConfigErrorReporter errorReporter)
         {
             // Host is optional when Path is specified
-            if (string.IsNullOrEmpty(host))
+            if (hosts == null || hosts.Count == 0)
             {
                 return true;
             }
 
-            if (!_hostNameRegex.IsMatch(host))
+            for (var i = 0; i < hosts.Count; i++)
             {
-                errorReporter.ReportError(ConfigErrors.ParsedRouteRuleInvalidMatcher, routeId, $"Invalid host name '{host}'");
-                return false;
+                if (string.IsNullOrEmpty(hosts[i]) || !_hostNameRegex.IsMatch(hosts[i]))
+                {
+                    errorReporter.ReportError(ConfigErrors.ParsedRouteRuleInvalidMatcher, routeId, $"Invalid host name '{hosts[i]}'");
+                    return false;
+                }
             }
 
             return true;

src/ReverseProxy/Service/ConfigModel/ParsedRoute.cs

@@ -23,7 +23,7 @@ internal class ParsedRoute
         /// <summary>
         /// Only match requests with the given Host header.
         /// </summary>
-        public string Host { get; set; }
+        public IReadOnlyList<string> Hosts { get; set; }
 
         /// <summary>
         /// Only match requests with the given Path pattern.
@@ -96,9 +96,11 @@ internal int GetConfigHash()
                     .Aggregate((total, nextCode) => total ^ nextCode);
             }
 
-            if (!string.IsNullOrEmpty(Host))
+            if (Hosts != null && Hosts.Count > 0)
             {
-                hash ^= Host.GetHashCode();
+                // Assumes un-ordered
+                hash ^= Hosts.Select(item => item.GetHashCode())
+                    .Aggregate((total, nextCode) => total ^ nextCode);
             }
 
             if (!string.IsNullOrEmpty(Path))

src/ReverseProxy/Service/DynamicEndpoints/RuntimeRouteBuilder.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Cors;
@@ -73,9 +74,9 @@ public RouteConfig Build(ParsedRoute source, ClusterInfo cluster, RouteInfo runt
             endpointBuilder.DisplayName = source.RouteId;
             endpointBuilder.Metadata.Add(newRouteConfig);
 
-            if (!string.IsNullOrEmpty(source.Host))
+            if (source.Hosts != null && source.Hosts.Count != 0)
             {
-                endpointBuilder.Metadata.Add(new AspNetCore.Routing.HostAttribute(source.Host));
+                endpointBuilder.Metadata.Add(new AspNetCore.Routing.HostAttribute(source.Hosts.ToArray()));
             }
 
             bool acceptCorsPreflight;

test/ReverseProxy.Tests/Abstractions/RouteDiscovery/Contract/ProxyRouteTests.cs

@@ -24,7 +24,7 @@ public void DeepClone_Works()
                 Match =
                 {
                     Methods = new[] { "GET", "POST" },
-                    Host = "example.com",
+                    Hosts = new[] { "example.com" },
                     Path = "/",
                 },
                 Priority = 2,
@@ -46,7 +46,7 @@ public void DeepClone_Works()
             Assert.NotSame(sut.Match, clone.Match);
             Assert.NotSame(sut.Match.Methods, clone.Match.Methods);
             Assert.Equal(sut.Match.Methods, clone.Match.Methods);
-            Assert.Equal(sut.Match.Host, clone.Match.Host);
+            Assert.Equal(sut.Match.Hosts, clone.Match.Hosts);
             Assert.Equal(sut.Match.Path, clone.Match.Path);
             Assert.Equal(sut.Priority, clone.Priority);
             Assert.Equal(sut.ClusterId, clone.ClusterId);
@@ -70,7 +70,7 @@ public void DeepClone_Nulls_Works()
             Assert.NotSame(sut, clone);
             Assert.Null(clone.RouteId);
             Assert.Null(clone.Match.Methods);
-            Assert.Null(clone.Match.Host);
+            Assert.Null(clone.Match.Hosts);
             Assert.Null(clone.Match.Path);
             Assert.Null(clone.Priority);
             Assert.Null(clone.ClusterId);

test/ReverseProxy.Tests/Service/Config/DynamicConfigBuilderTests.cs

@@ -40,7 +40,7 @@ public TestClustersRepo() { }
 
             public TestClustersRepo(IDictionary<string, Cluster> clusters) { Clusters = clusters; }
 
-            public IDictionary<string, Cluster>  Clusters { get; set; }
+            public IDictionary<string, Cluster> Clusters { get; set; }
 
             public Task<IDictionary<string, Cluster>> GetClustersAsync(CancellationToken cancellation) => Task.FromResult(Clusters);
 
@@ -143,7 +143,7 @@ public async Task BuildConfigAsync_OneCluster_Works()
         public async Task BuildConfigAsync_ValidRoute_Works()
         {
             var errorReporter = new TestConfigErrorReporter();
-            var route1 = new ProxyRoute { RouteId = "route1", Match = { Host = "example.com" }, Priority = 1, ClusterId = "cluster1" };
+            var route1 = new ProxyRoute { RouteId = "route1", Match = { Hosts = new[] { "example.com" } }, Priority = 1, ClusterId = "cluster1" };
             var configBuilder = CreateConfigBuilder(new TestClustersRepo(), new TestRoutesRepo(new[] { route1 }));
 
             var result = await configBuilder.BuildConfigAsync(errorReporter, CancellationToken.None);
@@ -159,7 +159,7 @@ public async Task BuildConfigAsync_ValidRoute_Works()
         public async Task BuildConfigAsync_RouteValidationError_SkipsRoute()
         {
             var errorReporter = new TestConfigErrorReporter();
-            var route1 = new ProxyRoute { RouteId = "route1", Match = { Host = "invalid host name" }, Priority = 1, ClusterId = "cluster1" };
+            var route1 = new ProxyRoute { RouteId = "route1", Match = { Hosts = new[] { "invalid host name" } }, Priority = 1, ClusterId = "cluster1" };
             var configBuilder = CreateConfigBuilder(new TestClustersRepo(), new TestRoutesRepo(new[] { route1 }));
 
             var result = await configBuilder.BuildConfigAsync(errorReporter, CancellationToken.None);
@@ -173,7 +173,7 @@ public async Task BuildConfigAsync_RouteValidationError_SkipsRoute()
         public async Task BuildConfigAsync_ConfigFilterRouteActions_CanFixBrokenRoute()
         {
             var errorReporter = new TestConfigErrorReporter();
-            var route1 = new ProxyRoute { RouteId = "route1", Match = { Host = "invalid host name" }, Priority = 1, ClusterId = "cluster1" };
+            var route1 = new ProxyRoute { RouteId = "route1", Match = { Hosts = new[] { "invalid host name" } }, Priority = 1, ClusterId = "cluster1" };
             var configBuilder = CreateConfigBuilder(new TestClustersRepo(), new TestRoutesRepo(new[] { route1 }),
                 proxyBuilder =>
                 {
@@ -188,7 +188,8 @@ public async Task BuildConfigAsync_ConfigFilterRouteActions_CanFixBrokenRoute()
             Assert.Single(result.Routes);
             var builtRoute = result.Routes[0];
             Assert.Same(route1.RouteId, builtRoute.RouteId);
-            Assert.Equal("example.com", builtRoute.Host);
+            var host = Assert.Single(builtRoute.Hosts);
+            Assert.Equal("example.com", host);
         }
 
         private class FixRouteHostFilter : IProxyConfigFilter
@@ -200,7 +201,7 @@ public Task ConfigureClusterAsync(Cluster cluster, CancellationToken cancel)
 
             public Task ConfigureRouteAsync(ProxyRoute route, CancellationToken cancel)
             {
-                route.Match.Host = "example.com";
+                route.Match.Hosts = new[] { "example.com" };
                 return Task.CompletedTask;
             }
         }
@@ -282,7 +283,7 @@ public async Task BuildConfigAsync_ConfigFilterClusterActionThrows_ClusterSkippe
         public async Task BuildConfigAsync_ConfigFilterRouteActions_Works()
         {
             var errorReporter = new TestConfigErrorReporter();
-            var route1 = new ProxyRoute { RouteId = "route1", Match = { Host = "example.com" }, Priority = 1, ClusterId = "cluster1" };
+            var route1 = new ProxyRoute { RouteId = "route1", Match = { Hosts = new[] { "example.com" } }, Priority = 1, ClusterId = "cluster1" };
             var configBuilder = CreateConfigBuilder(new TestClustersRepo(), new TestRoutesRepo(new[] { route1 }),
                 proxyBuilder =>
                 {
@@ -303,8 +304,8 @@ public async Task BuildConfigAsync_ConfigFilterRouteActions_Works()
         public async Task BuildConfigAsync_ConfigFilterRouteActionThrows_SkipsRoute()
         {
             var errorReporter = new TestConfigErrorReporter();
-            var route1 = new ProxyRoute { RouteId = "route1", Match = { Host = "example.com" }, Priority = 1, ClusterId = "cluster1" };
-            var route2 = new ProxyRoute { RouteId = "route2", Match = { Host = "example2.com" }, Priority = 1, ClusterId = "cluster2" };
+            var route1 = new ProxyRoute { RouteId = "route1", Match = { Hosts = new[] { "example.com" } }, Priority = 1, ClusterId = "cluster1" };
+            var route2 = new ProxyRoute { RouteId = "route2", Match = { Hosts = new[] { "example2.com" } }, Priority = 1, ClusterId = "cluster2" };
             var configBuilder = CreateConfigBuilder(new TestClustersRepo(), new TestRoutesRepo(new[] { route1, route2 }),
                 proxyBuilder =>
                 {

test/ReverseProxy.Tests/Service/Config/RuleParsing/RouteValidatorTests.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Authorization;
@@ -32,6 +33,7 @@ public void Constructor_Works()
         [InlineData("example.com", null, "get")]
         [InlineData("example.com", null, "gEt,put")]
         [InlineData("example.com", null, "gEt,put,POST,traCE,PATCH,DELETE,Head")]
+        [InlineData("example.com,example2.com", null, "get")]
         [InlineData("*.example.com", null, null)]
         [InlineData("a-b.example.com", null, null)]
         [InlineData("a-b.b-c.example.com", null, null)]
@@ -41,7 +43,7 @@ public async Task Accepts_ValidRules(string host, string path, string methods)
             var route = new ParsedRoute
             {
                 RouteId = "route1",
-                Host = host,
+                Hosts = host?.Split(",") ?? Array.Empty<string>(),
                 Path = path,
                 Methods = methods?.Split(","),
                 ClusterId = "cluster1",
@@ -73,14 +75,18 @@ public async Task Rejects_MissingRouteId(string routeId)
             Assert.Contains(errorReporter.Errors, err => err.ErrorCode == ConfigErrors.ParsedRouteMissingId);
         }
 
-        [Fact]
-        public async Task Rejects_MissingHostAndPath()
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        [InlineData("example.com,")]
+        public async Task Rejects_MissingHostAndPath(string host)
         {
             // Arrange
             var route = new ParsedRoute
             {
                 RouteId = "route1",
                 ClusterId = "cluster1",
+                Hosts = host?.Split(",")
             };
 
             // Act
@@ -103,13 +109,14 @@ public async Task Rejects_MissingHostAndPath()
         [InlineData("a.-example.com")]
         [InlineData("a.example-.com")]
         [InlineData("a.-example-.com")]
+        [InlineData("example.com,example-.com")]
         public async Task Rejects_InvalidHost(string host)
         {
             // Arrange
             var route = new ParsedRoute
             {
                 RouteId = "route1",
-                Host = host,
+                Hosts = host.Split(","),
                 ClusterId = "cluster1",
             };
 
@@ -176,7 +183,7 @@ public async Task Accepts_ReservedAuthorizationPolicy(string policy)
             {
                 RouteId = "route1",
                 AuthorizationPolicy = policy,
-                Host = "localhost",
+                Hosts = new[] { "localhost" },
                 ClusterId = "cluster1",
             };
 
@@ -196,7 +203,7 @@ public async Task Accepts_CustomAuthorizationPolicy()
             {
                 RouteId = "route1",
                 AuthorizationPolicy = "custom",
-                Host = "localhost",
+                Hosts = new[] { "localhost" },
                 ClusterId = "cluster1",
             };
 
@@ -233,7 +240,7 @@ public async Task Accepts_ReservedCorsPolicy(string policy)
             {
                 RouteId = "route1",
                 CorsPolicy = policy,
-                Host = "localhost",
+                Hosts = new[] { "localhost" },
                 ClusterId = "cluster1",
             };
 
@@ -253,7 +260,7 @@ public async Task Accepts_CustomCorsPolicy()
             {
                 RouteId = "route1",
                 CorsPolicy = "custom",
-                Host = "localhost",
+                Hosts = new[] { "localhost" },
                 ClusterId = "cluster1",
             };