Fix issue #936: Kubernetes service discovery provider doesn't allow cross-namespace discovery (#938)

* Allow default k8s namespace to be overridden

* Add ServiceNamespace to ReRoute configuration

* Remove debug comments

* Update unit tests

* Unit tests (Eureka)

* Update docs

* Re-run build

docs/features/kubernetes.rst

@@ -75,3 +75,21 @@ The polling interval is in milliseconds and tells Ocelot how often to call kuber
 
 Please note there are tradeoffs here. If you poll kubernetes it is possible Ocelot will not know if a service is down depending on your polling interval and you might get more errors than if you get the latest services per request. This really depends on how volatile your services are. I doubt it will matter for most people and polling may give a tiny performance improvement over calling kubernetes per request. 
 There is no way for Ocelot to work these out for you. 
+
+If your downstream service resides in a different namespace you can override the global setting at the ReRoute level by specifying a ServiceNamespace
+
+
+.. code-block:: json
+
+{
+  "ReRoutes": [
+    {
+      "DownstreamPathTemplate": "/api/values",
+      "DownstreamScheme": "http",
+      "UpstreamPathTemplate": "/values",
+      "ServiceName": "downstreamservice",
+      "ServiceNamespace": "downstream-namespace",
+      "UpstreamHttpMethod": [ "Get" ]     
+    }
+  ]
+}

src/Ocelot.Provider.Consul/ConsulProviderFactory.cs

@@ -6,13 +6,13 @@
 
     public static class ConsulProviderFactory
     {
-        public static ServiceDiscoveryFinderDelegate Get = (provider, config, name) =>
+        public static ServiceDiscoveryFinderDelegate Get = (provider, config, reRoute) =>
         {
             var factory = provider.GetService<IOcelotLoggerFactory>();
 
             var consulFactory = provider.GetService<IConsulClientFactory>();
 
-            var consulRegistryConfiguration = new ConsulRegistryConfiguration(config.Host, config.Port, name, config.Token);
+            var consulRegistryConfiguration = new ConsulRegistryConfiguration(config.Host, config.Port, reRoute.ServiceName, config.Token);
 
             var consulServiceDiscoveryProvider = new Consul(consulRegistryConfiguration, factory, consulFactory);
 

src/Ocelot.Provider.Eureka/EurekaProviderFactory.cs

@@ -6,13 +6,13 @@
 
     public static class EurekaProviderFactory
     {
-        public static ServiceDiscoveryFinderDelegate Get = (provider, config, name) =>
+        public static ServiceDiscoveryFinderDelegate Get = (provider, config, reRoute) =>
         {
             var client = provider.GetService<IDiscoveryClient>();
 
             if (config.Type?.ToLower() == "eureka" && client != null)
             {
-                return new Eureka(name, client);
+                return new Eureka(reRoute.ServiceName, client);
             }
 
             return null;

src/Ocelot.Provider.Kubernetes/KubeProvider.cs

@@ -24,8 +24,7 @@ namespace Ocelot.Provider.Kubernetes
 
         public async Task<List<Service>> Get()
         {
-            var service = await kubeApi.ServicesV1()
-                .Get(kubeRegistryConfiguration.KeyOfServiceInK8s, kubeRegistryConfiguration.KubeNamespace);
+            var service = await kubeApi.ServicesV1().Get(kubeRegistryConfiguration.KeyOfServiceInK8s, kubeRegistryConfiguration.KubeNamespace);
             var services = new List<Service>();
             if (IsValid(service))
             {

src/Ocelot.Provider.Kubernetes/KubernetesProviderFactory.cs

@@ -3,24 +3,25 @@ using Microsoft.Extensions.DependencyInjection;
 using Ocelot.Logging;
 using Ocelot.ServiceDiscovery;
 using System;
+using Ocelot.Configuration;
 
 namespace Ocelot.Provider.Kubernetes
 {
     public static class KubernetesProviderFactory
     {
-        public static ServiceDiscoveryFinderDelegate Get = (provider, config, name) =>
+        public static ServiceDiscoveryFinderDelegate Get = (provider, config, reRoute) =>
         {
             var factory = provider.GetService<IOcelotLoggerFactory>();
-            return GetkubeProvider(provider, config, name, factory);
+            return GetkubeProvider(provider, config, reRoute, factory);
         };
 
-        private static ServiceDiscovery.Providers.IServiceDiscoveryProvider GetkubeProvider(IServiceProvider provider, Configuration.ServiceProviderConfiguration config, string name, IOcelotLoggerFactory factory)
+        private static ServiceDiscovery.Providers.IServiceDiscoveryProvider GetkubeProvider(IServiceProvider provider, Configuration.ServiceProviderConfiguration config, DownstreamReRoute reRoute, IOcelotLoggerFactory factory)
         {
             var kubeClient = provider.GetService<IKubeApiClient>();
             var k8sRegistryConfiguration = new KubeRegistryConfiguration()
             {
-                KeyOfServiceInK8s = name,
-                KubeNamespace = config.Namespace,
+                KeyOfServiceInK8s = reRoute.ServiceName,
+                KubeNamespace = string.IsNullOrEmpty(reRoute.ServiceNamespace) ? config.Namespace : reRoute.ServiceNamespace
             };
 
             var k8sServiceDiscoveryProvider = new Kube(k8sRegistryConfiguration, factory, kubeClient);

src/Ocelot/Configuration/Builder/DownstreamReRouteBuilder.cs

@@ -30,6 +30,7 @@ namespace Ocelot.Configuration.Builder
         private RateLimitOptions _rateLimitOptions;
         private bool _useServiceDiscovery;
         private string _serviceName;
+        private string _serviceNamespace;
         private List<HeaderFindAndReplace> _upstreamHeaderFindAndReplace;
         private List<HeaderFindAndReplace> _downstreamHeaderFindAndReplace;
         private readonly List<DownstreamHostAndPort> _downstreamAddresses;
@@ -186,6 +187,12 @@ namespace Ocelot.Configuration.Builder
             return this;
         }
         
+        public DownstreamReRouteBuilder WithServiceNamespace(string serviceNamespace)
+        {
+            _serviceNamespace = serviceNamespace;
+            return this;
+        }
+
         public DownstreamReRouteBuilder WithUpstreamHeaderFindAndReplace(List<HeaderFindAndReplace> upstreamHeaderFindAndReplace)
         {
             _upstreamHeaderFindAndReplace = upstreamHeaderFindAndReplace;
@@ -243,6 +250,7 @@ namespace Ocelot.Configuration.Builder
                 _downstreamHeaderFindAndReplace,
                 _downstreamAddresses,
                 _serviceName,
+                _serviceNamespace,
                 _httpHandlerOptions,
                 _useServiceDiscovery,
                 _enableRateLimiting,

src/Ocelot/Configuration/Creator/ReRoutesCreator.cs

@@ -126,6 +126,7 @@ namespace Ocelot.Configuration.Creator
                 .WithRateLimitOptions(rateLimitOption)
                 .WithHttpHandlerOptions(httpHandlerOptions)
                 .WithServiceName(fileReRoute.ServiceName)
+                .WithServiceNamespace(fileReRoute.ServiceNamespace)
                 .WithUseServiceDiscovery(fileReRouteOptions.UseServiceDiscovery)
                 .WithUpstreamHeaderFindAndReplace(hAndRs.Upstream)
                 .WithDownstreamHeaderFindAndReplace(hAndRs.Downstream)

src/Ocelot/Configuration/DownstreamReRoute.cs

@@ -13,6 +13,7 @@ namespace Ocelot.Configuration
             List<HeaderFindAndReplace> downstreamHeadersFindAndReplace,
             List<DownstreamHostAndPort> downstreamAddresses,
             string serviceName,
+            string serviceNamespace,
             HttpHandlerOptions httpHandlerOptions,
             bool useServiceDiscovery,
             bool enableEndpointEndpointRateLimiting,
@@ -47,6 +48,7 @@ namespace Ocelot.Configuration
             DownstreamHeadersFindAndReplace = downstreamHeadersFindAndReplace ?? new List<HeaderFindAndReplace>();
             DownstreamAddresses = downstreamAddresses ?? new List<DownstreamHostAndPort>();
             ServiceName = serviceName;
+            ServiceNamespace = serviceNamespace;
             HttpHandlerOptions = httpHandlerOptions;
             UseServiceDiscovery = useServiceDiscovery;
             EnableEndpointEndpointRateLimiting = enableEndpointEndpointRateLimiting;
@@ -76,6 +78,7 @@ namespace Ocelot.Configuration
         public List<HeaderFindAndReplace> DownstreamHeadersFindAndReplace { get; }
         public List<DownstreamHostAndPort> DownstreamAddresses { get; }
         public string ServiceName { get; }
+        public string ServiceNamespace { get; }
         public HttpHandlerOptions HttpHandlerOptions { get; }
         public bool UseServiceDiscovery { get; }
         public bool EnableEndpointEndpointRateLimiting { get; }

src/Ocelot/Configuration/File/FileReRoute.cs

@@ -38,6 +38,7 @@ namespace Ocelot.Configuration.File
         public FileCacheOptions FileCacheOptions { get; set; }
         public bool ReRouteIsCaseSensitive { get; set; }
         public string ServiceName { get; set; }
+        public string ServiceNamespace { get; set; }
         public string DownstreamScheme { get; set; }
         public FileQoSOptions QoSOptions { get; set; }
         public FileLoadBalancerOptions LoadBalancerOptions { get; set; }

src/Ocelot/ServiceDiscovery/ServiceDiscoveryFinderDelegate.cs

@@ -4,5 +4,5 @@ namespace Ocelot.ServiceDiscovery
     using Providers;
     using System;
 
-    public delegate IServiceDiscoveryProvider ServiceDiscoveryFinderDelegate(IServiceProvider provider, ServiceProviderConfiguration config, string key);
+    public delegate IServiceDiscoveryProvider ServiceDiscoveryFinderDelegate(IServiceProvider provider, ServiceProviderConfiguration config, DownstreamReRoute reRoute);
 }

src/Ocelot/ServiceDiscovery/ServiceDiscoveryProviderFactory.cs

@@ -27,7 +27,7 @@ namespace Ocelot.ServiceDiscovery
         {
             if (reRoute.UseServiceDiscovery)
             {
-                return GetServiceDiscoveryProvider(serviceConfig, reRoute.ServiceName);
+                return GetServiceDiscoveryProvider(serviceConfig, reRoute);
             }
 
             var services = new List<Service>();
@@ -42,17 +42,17 @@ namespace Ocelot.ServiceDiscovery
             return new OkResponse<IServiceDiscoveryProvider>(new ConfigurationServiceProvider(services));
         }
 
-        private Response<IServiceDiscoveryProvider> GetServiceDiscoveryProvider(ServiceProviderConfiguration config, string key)
+        private Response<IServiceDiscoveryProvider> GetServiceDiscoveryProvider(ServiceProviderConfiguration config, DownstreamReRoute reRoute)
         {
             if (config.Type?.ToLower() == "servicefabric")
             {
-                var sfConfig = new ServiceFabricConfiguration(config.Host, config.Port, key);
+                var sfConfig = new ServiceFabricConfiguration(config.Host, config.Port, reRoute.ServiceName);
                 return new OkResponse<IServiceDiscoveryProvider>(new ServiceFabricServiceDiscoveryProvider(sfConfig));
             }
 
             if (_delegates != null)
             {
-                var provider = _delegates?.Invoke(_provider, config, key);
+                var provider = _delegates?.Invoke(_provider, config, reRoute);
 
                 if (provider.GetType().Name.ToLower() == config.Type.ToLower())
                 {

test/Ocelot.UnitTests/Consul/ProviderFactoryTests.cs

@@ -1,4 +1,6 @@
-namespace Ocelot.UnitTests.Consul
+using Ocelot.Configuration.Builder;
+
+namespace Ocelot.UnitTests.Consul
 {
     using Microsoft.Extensions.DependencyInjection;
     using Moq;
@@ -29,7 +31,11 @@
         [Fact]
         public void should_return_ConsulServiceDiscoveryProvider()
         {
-            var provider = ConsulProviderFactory.Get(_provider, new ServiceProviderConfiguration("", "", 1, "", "", 1), "");
+            var reRoute = new DownstreamReRouteBuilder()
+                .WithServiceName("")
+                .Build();
+
+            var provider = ConsulProviderFactory.Get(_provider, new ServiceProviderConfiguration("", "", 1, "", "", 1), reRoute);
             provider.ShouldBeOfType<Consul>();
         }
 
@@ -37,7 +43,12 @@
         public void should_return_PollingConsulServiceDiscoveryProvider()
         {
             var stopsPollerFromPolling = 10000;
-            var provider = ConsulProviderFactory.Get(_provider, new ServiceProviderConfiguration("pollconsul", "", 1, "", "", stopsPollerFromPolling), "");
+
+            var reRoute = new DownstreamReRouteBuilder()
+                .WithServiceName("")
+                .Build();
+
+            var provider = ConsulProviderFactory.Get(_provider, new ServiceProviderConfiguration("pollconsul", "", 1, "", "", stopsPollerFromPolling), reRoute);
             provider.ShouldBeOfType<PollConsul>();
         }
     }

test/Ocelot.UnitTests/Eureka/EurekaProviderFactoryTests.cs

@@ -27,7 +27,10 @@
             var services = new ServiceCollection();
             services.AddSingleton<IDiscoveryClient>(client.Object);
             var sp = services.BuildServiceProvider();
-            var provider = EurekaProviderFactory.Get(sp, config, null);
+            var reRoute = new DownstreamReRouteBuilder()
+                .WithServiceName("")
+                .Build();
+            var provider = EurekaProviderFactory.Get(sp, config, reRoute);
             provider.ShouldBeOfType<Eureka>();
         }
     }