Reload config on change (#527)

* Reload config on change.
Added test case.

* added testing for adding the json with reloadOnChange = false

test/Ocelot.AcceptanceTests/ConfigurationReloadTests.cs

@@ -0,0 +1,68 @@
+using Ocelot.Configuration.File;
+using Ocelot.Configuration.Setter;
+using Ocelot.Middleware;
+using Shouldly;
+using System;
+using System.Collections.Generic;
+using System.Text;
+using TestStack.BDDfy;
+using Xunit;
+
+namespace Ocelot.AcceptanceTests
+{
+    public class ConfigurationReloadTests : IDisposable
+    {
+        private FileConfiguration _initialConfig;
+        private FileConfiguration _anotherConfig;
+        private Steps _steps;
+
+        public ConfigurationReloadTests()
+        {
+            _steps = new Steps();
+
+            _initialConfig = new FileConfiguration
+            {
+                GlobalConfiguration = new FileGlobalConfiguration
+                {
+                    RequestIdKey = "initialKey"
+                }
+            };
+
+            _anotherConfig = new FileConfiguration
+            {
+                GlobalConfiguration = new FileGlobalConfiguration
+                {
+                    RequestIdKey = "someOtherKey"
+                }
+            };
+        }
+
+        [Fact]
+        public void should_reload_config_on_change()
+        {           
+            this.Given(x => _steps.GivenThereIsAConfiguration(_initialConfig))
+                .And(x => _steps.GivenOcelotIsRunningReloadingConfig(true))
+                .And(x => _steps.GivenThereIsAConfiguration(_anotherConfig))
+                .And(x => _steps.GivenIWait(2500))
+                .And(x => _steps.ThenConfigShouldBe(_anotherConfig))
+                .BDDfy();
+        }
+
+        [Fact]
+        public void should_not_reload_config_on_change()
+        {
+           
+            this.Given(x => _steps.GivenThereIsAConfiguration(_initialConfig))
+                .And(x => _steps.GivenOcelotIsRunningReloadingConfig(false))
+                .And(x => _steps.GivenThereIsAConfiguration(_anotherConfig))
+                .And(x => _steps.GivenIWait(2500))
+                .And(x => _steps.ThenConfigShouldBe(_initialConfig))
+                .BDDfy();
+        }
+
+        public void Dispose()
+        {
+            _steps.Dispose();
+        }
+    }
+}

test/Ocelot.AcceptanceTests/Steps.cs

@@ -34,6 +34,7 @@ namespace Ocelot.AcceptanceTests
     using Butterfly;
     using Configuration.Repository;
     using Microsoft.Net.Http.Headers;
+    using Ocelot.Configuration.Creator;
     using MediaTypeHeaderValue = System.Net.Http.Headers.MediaTypeHeaderValue;
 
     public class Steps : IDisposable
@@ -55,6 +56,18 @@ namespace Ocelot.AcceptanceTests
             _random = new Random();
         }
 
+        public async Task ThenConfigShouldBe(FileConfiguration fileConfig)
+        {
+            var internalConfigCreator = _ocelotServer.Host.Services.GetService<IInternalConfigurationCreator>();
+
+            var internalConfigRepo = _ocelotServer.Host.Services.GetService<IInternalConfigurationRepository>();
+            var internalConfig = internalConfigRepo.Get();
+
+            var config = await internalConfigCreator.Create(fileConfig);
+
+            internalConfig.Data.RequestId.ShouldBe(config.Data.RequestId);
+        }
+
         public async Task StartFakeOcelotWithWebSockets()
         {
             _ocelotBuilder = new WebHostBuilder();
@@ -116,6 +129,34 @@ namespace Ocelot.AcceptanceTests
             File.WriteAllText(configurationPath, jsonConfiguration);
         }
 
+        public void GivenOcelotIsRunningReloadingConfig(bool shouldReload)
+        {
+            _webHostBuilder = new WebHostBuilder();
+
+            _webHostBuilder
+                .ConfigureAppConfiguration((hostingContext, config) =>
+                {
+                    config.SetBasePath(hostingContext.HostingEnvironment.ContentRootPath);
+                    var env = hostingContext.HostingEnvironment;
+                    config.AddJsonFile("appsettings.json", optional: true, reloadOnChange: false)
+                        .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: false);
+                    config.AddJsonFile("ocelot.json", optional: false, reloadOnChange: shouldReload);
+                    config.AddEnvironmentVariables();
+                })
+                .ConfigureServices(s =>
+                {
+                    s.AddOcelot();                    
+                })
+                .Configure(app =>
+                {
+                    app.UseOcelot().Wait();
+                });
+
+            _ocelotServer = new TestServer(_webHostBuilder);
+
+            _ocelotClient = _ocelotServer.CreateClient();
+        }
+
         /// <summary>
         /// This is annoying cos it should be in the constructor but we need to set up the file before calling startup so its a step.
         /// </summary>