MTTL-376 Setup boiler plate code for logging the correlation ID

SearchApi.Tests/Properties/launchSettings.json

@@ -0,0 +1,27 @@
+{
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:51761/",
+      "sslPort": 44398
+    }
+  },
+  "profiles": {
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "LBH_search_api.Tests": {
+      "commandName": "Project",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      },
+      "applicationUrl": "https://localhost:5001;http://localhost:5000"
+    }
+  }
+}

SearchApi.Tests/V1/Controllers/BaseControllerTests.cs

@@ -0,0 +1,52 @@
+using System.Collections.Generic;
+using FluentAssertions;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Controllers;
+using Microsoft.AspNetCore.Routing;
+using NUnit.Framework;
+using SearchApi.V1.Controllers;
+using SearchApi.V1.Infrastructure;
+
+namespace SearchApi.Tests.V1.Controllers
+{
+    [TestFixture]
+    public class BaseControllerTests
+    {
+        private BaseController _sut;
+        private ControllerContext _controllerContext;
+        private HttpContext _stubHttpContext;
+
+        [SetUp]
+        public void Init()
+        {
+            _stubHttpContext = new DefaultHttpContext();
+            _controllerContext = new ControllerContext(new ActionContext(_stubHttpContext, new RouteData(), new ControllerActionDescriptor()));
+            _sut = new BaseController();
+
+            _sut.ControllerContext = _controllerContext;
+        }
+
+        [Test]
+        public void GetCorrelationShouldThrowExceptionIfCorrelationHeaderUnavailable()
+        {
+            // Arrange + Act + Assert
+            _sut.Invoking(x => x.GetCorrelationId())
+                .Should().Throw<KeyNotFoundException>()
+                .WithMessage("Request is missing a correlationId");
+        }
+
+        [Test]
+        public void GetCorrelationShouldReturnCorrelationIdWhenExists()
+        {
+            // Arrange
+            _stubHttpContext.Request.Headers.Add(Constants.CorrelationId, "123");
+
+            // Act
+            var result = _sut.GetCorrelationId();
+
+            // Assert
+            result.Should().BeEquivalentTo("123");
+        }
+    }
+}

SearchApi.Tests/V1/Gateways/ExampleGatewayTests.cs

@@ -10,7 +10,7 @@ namespace SearchApi.Tests.V1.Gateways
     //TODO: Rename Tests to match gateway name
     //For instruction on how to run tests please see the wiki: https://github.com/LBHackney-IT/lbh-base-api/wiki/Running-the-test-suite.
     [TestFixture]
-    [Ignore("Deciding on what DB to use")]
+    [Ignore("Not needed until we decide on DB")]
     public class ExampleGatewayTests : DatabaseTests
     {
         private readonly Fixture _fixture = new Fixture();

SearchApi.Tests/V1/Infrastructure/CorrelationMiddlewareTest.cs

@@ -0,0 +1,49 @@
+using System.Threading.Tasks;
+using FluentAssertions;
+using Microsoft.AspNetCore.Http;
+using NUnit.Framework;
+using SearchApi.V1.Infrastructure;
+
+namespace SearchApi.Tests.V1.Infrastructure
+{
+    [TestFixture]
+    public class CorrelationMiddlewareTest
+    {
+        private CorrelationMiddleware _sut;
+
+        [SetUp]
+        public void Init()
+        {
+            _sut = new CorrelationMiddleware(null);
+        }
+
+        [Test]
+        public async Task DoesNotReplaceCorrelationIdIfOneExists()
+        {
+            // Arrange
+            var httpContext = new DefaultHttpContext();
+            var headerValue = "123";
+
+            httpContext.HttpContext.Request.Headers.Add(Constants.CorrelationId, headerValue);
+
+            // Act
+            await _sut.InvokeAsync(httpContext).ConfigureAwait(false);
+
+            // Assert
+            httpContext.HttpContext.Request.Headers[Constants.CorrelationId].Should().BeEquivalentTo(headerValue);
+        }
+
+        [Test]
+        public async Task AddsCorrelationIdIfOneDoesNotExist()
+        {
+            // Arrange
+            var httpContext = new DefaultHttpContext();
+
+            // Act
+            await _sut.InvokeAsync(httpContext).ConfigureAwait(false);
+
+            // Assert
+            httpContext.HttpContext.Request.Headers[Constants.CorrelationId].Should().HaveCountGreaterThan(0);
+        }
+    }
+}

SearchApi.Tests/V1/Infrastructure/ExampleContextTests.cs

@@ -5,7 +5,7 @@
 namespace SearchApi.Tests.V1.Infrastructure
 {
     [TestFixture]
-    [Ignore("Deciding on what DB to use")]
+    [Ignore("Not needed until we decide on DB")]
     public class DatabaseContextTest : DatabaseTests
     {
         [Test]

SearchApi/Startup.cs

@@ -132,6 +132,8 @@ private static void RegisterUseCases(IServiceCollection services)
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
         public static void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         {
+            app.UseCorrelation();
+
             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();

SearchApi/V1/Controllers/BaseController.cs

@@ -1,6 +1,8 @@
+using System.Collections.Generic;
 using Microsoft.AspNetCore.Mvc;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
+using SearchApi.V1.Infrastructure;
 
 namespace SearchApi.V1.Controllers
 {
@@ -11,6 +13,14 @@ public BaseController()
             ConfigureJsonSerializer();
         }
 
+        public string GetCorrelationId()
+        {
+            if (HttpContext.Request.Headers[Constants.CorrelationId].Count == 0)
+                throw new KeyNotFoundException("Request is missing a correlationId");
+
+            return HttpContext.Request.Headers[Constants.CorrelationId];
+        }
+
         public static void ConfigureJsonSerializer()
         {
             JsonConvert.DefaultSettings = () =>

SearchApi/V1/Infrastructure/Constants.cs

@@ -0,0 +1,7 @@
+namespace SearchApi.V1.Infrastructure
+{
+    public static class Constants
+    {
+        public const string CorrelationId = "x-correlation-id";
+    }
+}

SearchApi/V1/Infrastructure/CorrelationMiddleware.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
+
+namespace SearchApi.V1.Infrastructure
+{
+    public class CorrelationMiddleware
+    {
+        private readonly RequestDelegate _next;
+
+        public CorrelationMiddleware(RequestDelegate next)
+        {
+            _next = next;
+        }
+
+        public async Task InvokeAsync(HttpContext context)
+        {
+            if (context.Request.Headers[Constants.CorrelationId].Count == 0)
+            {
+                context.Request.Headers[Constants.CorrelationId] = Guid.NewGuid().ToString();
+            }
+
+            if (_next != null)
+                await _next(context).ConfigureAwait(false);
+        }
+    }
+
+    public static class CorrelationMiddlewareExtensions
+    {
+        public static IApplicationBuilder UseCorrelation(
+            this IApplicationBuilder builder)
+        {
+            return builder.UseMiddleware<CorrelationMiddleware>();
+        }
+    }
+}