Feature/poll consul (#392)

* WIP - implement a consul service discovery poller, lots of shared code with existing, refactor next and a todo in the docs to finish

* #374 implement polling for consul as option

* #374 updated docs to remove todo

* #374 fixed failing unit test

* #374 fixed failing unit test

* #374 fixed failing acceptance test

test/Ocelot.AcceptanceTests/ServiceDiscoveryTests.cs

@@ -458,6 +458,64 @@ namespace Ocelot.AcceptanceTests
                 .BDDfy();
         }
 
+        [Fact]
+        public void should_handle_request_to_poll_consul_for_downstream_service_and_make_request()
+        {
+            const int consulPort = 8518;
+            const string serviceName = "web";
+            const int downstreamServicePort = 8082;
+            var downstreamServiceOneUrl = $"http://localhost:{downstreamServicePort}";
+            var fakeConsulServiceDiscoveryUrl = $"http://localhost:{consulPort}";
+            var serviceEntryOne = new ServiceEntry()
+            {
+                Service = new AgentService()
+                {
+                    Service = serviceName,
+                    Address = "localhost",
+                    Port = downstreamServicePort,
+                    ID = $"web_90_0_2_224_{downstreamServicePort}",
+                    Tags = new[] {"version-v1"}
+                },
+            };
+
+            var configuration = new FileConfiguration
+            {
+                ReRoutes = new List<FileReRoute>
+                    {
+                        new FileReRoute
+                        {
+                            DownstreamPathTemplate = "/api/home",
+                            DownstreamScheme = "http",
+                            UpstreamPathTemplate = "/home",
+                            UpstreamHttpMethod = new List<string> { "Get", "Options" },
+                            ServiceName = serviceName,
+                            LoadBalancerOptions = new FileLoadBalancerOptions { Type = "LeastConnection" },
+                            UseServiceDiscovery = true,
+                        }
+                    },
+                    GlobalConfiguration = new FileGlobalConfiguration()
+                    {
+                        ServiceDiscoveryProvider = new FileServiceDiscoveryProvider()
+                        {
+                            Host = "localhost",
+                            Port = consulPort,
+                            Type = "PollConsul",
+                            PollingInterval = 0
+                        }
+                    }
+            };
+
+            this.Given(x => x.GivenThereIsAServiceRunningOn(downstreamServiceOneUrl, "/api/home", 200, "Hello from Laura"))                
+            .And(x => x.GivenThereIsAFakeConsulServiceDiscoveryProvider(fakeConsulServiceDiscoveryUrl, serviceName))
+            .And(x => x.GivenTheServicesAreRegisteredWithConsul(serviceEntryOne))
+            .And(x => _steps.GivenThereIsAConfiguration(configuration))
+            .And(x => _steps.GivenOcelotIsRunning())
+                .When(x => _steps.WhenIGetUrlOnTheApiGatewayWaitingForTheResponseToBeOk("/home"))
+            .Then(x => _steps.ThenTheStatusCodeShouldBe(HttpStatusCode.OK))
+            .And(x => _steps.ThenTheResponseBodyShouldBe("Hello from Laura"))
+            .BDDfy();
+        }
+
         private void WhenIAddAServiceBackIn(ServiceEntry serviceEntryTwo)
         {
             _consulServices.Add(serviceEntryTwo);

test/Ocelot.AcceptanceTests/Steps.cs

@@ -27,6 +27,7 @@ using System.Text;
 using static Ocelot.AcceptanceTests.HttpDelegatingHandlersTests;
 using Ocelot.Requester;
 using Ocelot.Middleware.Multiplexer;
+using static Ocelot.Infrastructure.Wait;
 
 namespace Ocelot.AcceptanceTests
 {
@@ -675,6 +676,24 @@ namespace Ocelot.AcceptanceTests
             _response = _ocelotClient.GetAsync(url).Result;
         }
 
+        public void WhenIGetUrlOnTheApiGatewayWaitingForTheResponseToBeOk(string url)
+        {
+            var result = WaitFor(2000).Until(() => {
+                try
+                {
+                    _response = _ocelotClient.GetAsync(url).Result;
+                    _response.EnsureSuccessStatusCode();
+                    return true;
+                }
+                catch(Exception)
+                {
+                    return false;
+                }
+            });
+
+            result.ShouldBeTrue();
+        }
+
         public void WhenIGetUrlOnTheApiGateway(string url, string cookie, string value)
         {
             var request = _ocelotServer.CreateRequest(url);