From a90b985bcb5d6af6e402573b755bbd6821a5543e Mon Sep 17 00:00:00 2001
From: plockwood <paul.lockwood@education.gov.uk>
Date: Wed, 4 Oct 2023 17:41:44 +0100
Subject: [PATCH] add serilog and api user enricher

---
 TramsDataApi/Program.cs                       | 58 ++++++++++++-------
 .../SerilogCustomEnrichers/ApiUserEnricher.cs | 57 ++++++++++++++++++
 TramsDataApi/Startup.cs                       |  5 ++
 TramsDataApi/TramsDataApi.csproj              |  2 +
 TramsDataApi/appsettings.json                 | 18 +++++-
 5 files changed, 117 insertions(+), 23 deletions(-)
 create mode 100644 TramsDataApi/SerilogCustomEnrichers/ApiUserEnricher.cs

diff --git a/TramsDataApi/Program.cs b/TramsDataApi/Program.cs
index ff5fdce29..c3980562f 100644
--- a/TramsDataApi/Program.cs
+++ b/TramsDataApi/Program.cs
@@ -1,25 +1,39 @@
-using Microsoft.AspNetCore.Hosting;
-using Microsoft.Extensions.Hosting;
+using Microsoft.ApplicationInsights.Extensibility;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Mvc.ApiExplorer;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
+using Serilog;
+using System;
+using TramsDataApi;
+using TramsDataApi.SerilogCustomEnrichers;
 
-namespace TramsDataApi
+var builder = WebApplication.CreateBuilder(args);
+
+
+var startup = new Startup(builder.Configuration);
+
+startup.ConfigureServices(builder.Services);
+
+builder.Host.UseSerilog((context, services, loggerConfiguration) =>
 {
-    public class Program
-    {
-        public static void Main(string[] args)
-        {
-            CreateHostBuilder(args).Build().Run();
-        }
-
-        public static IHostBuilder CreateHostBuilder(string[] args)
-        {
-            var builder = Host.CreateDefaultBuilder(args);
-            return builder.ConfigureLogging(c =>
-                {
-                    c.ClearProviders();
-                    c.AddConsole();
-                })
-                .ConfigureWebHostDefaults(webBuilder => { webBuilder.UseStartup<Startup>(); });
-        }
-    }
-}
\ No newline at end of file
+    var enricher = services.GetRequiredService<ApiUserEnricher>();
+
+    loggerConfiguration
+    .WriteTo.ApplicationInsights(services.GetRequiredService<TelemetryConfiguration>(), TelemetryConverter.Traces)
+    .Enrich.FromLogContext()
+    .Enrich.With(enricher)
+    .WriteTo.Console();
+    });
+
+var app = builder.Build();
+
+var provider = app.Services.GetRequiredService<IApiVersionDescriptionProvider>();
+
+startup.Configure(app, app.Environment, provider);
+
+ILogger<Program> logger = app.Services.GetRequiredService<ILogger<Program>>();
+
+logger.LogInformation("Logger is working...");
+
+app.Run();
diff --git a/TramsDataApi/SerilogCustomEnrichers/ApiUserEnricher.cs b/TramsDataApi/SerilogCustomEnrichers/ApiUserEnricher.cs
new file mode 100644
index 000000000..683585ebc
--- /dev/null
+++ b/TramsDataApi/SerilogCustomEnrichers/ApiUserEnricher.cs
@@ -0,0 +1,57 @@
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Configuration;
+using Serilog.Core;
+using Serilog.Events;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using TramsDataApi.ResponseModels;
+using TramsDataApi.UseCases;
+
+namespace TramsDataApi.SerilogCustomEnrichers
+{
+    public class ApiUserEnricher : ILogEventEnricher
+    {
+        private readonly IHttpContextAccessor _httpContextAccessor;
+        private readonly IUseCase<string, ApiUser> _apiKeyService;
+
+        public ApiUserEnricher(IHttpContextAccessor httpContextAccessor, IUseCase<string, ApiUser> apiKeyService)
+        {
+            _httpContextAccessor = httpContextAccessor;
+            _apiKeyService = apiKeyService;
+        }
+
+        public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
+        {
+            var httpContext = _httpContextAccessor.HttpContext;
+
+            if (httpContext is null)
+            {
+                return;
+            }
+
+            ApiUser user = null;
+
+            if (httpContext.Request.Headers.TryGetValue("ApiKey", out var apiKey))
+            {
+                user = _apiKeyService.Execute(apiKey);
+            }
+
+            var httpContextModel = new HttpContextModel
+            {
+                Method = httpContext.Request.Method,
+                User = user?.UserName ?? "Unknow or not applicable"
+
+            };
+
+            logEvent.AddPropertyIfAbsent(propertyFactory.CreateProperty("ApiUser", httpContextModel.User, true));
+        }
+    }
+
+    public class HttpContextModel
+    {
+        public string Method { get; init; }
+
+        public string User { get; init; }
+    }
+}
diff --git a/TramsDataApi/Startup.cs b/TramsDataApi/Startup.cs
index 5c4ed6db1..0ca076828 100644
--- a/TramsDataApi/Startup.cs
+++ b/TramsDataApi/Startup.cs
@@ -15,6 +15,8 @@ namespace TramsDataApi
     using Middleware;
     using Swagger;
     using UseCases;
+    using TramsDataApi.SerilogCustomEnrichers;
+    using TramsDataApi.ResponseModels;
 
     public class Startup
     {
@@ -93,6 +95,9 @@ public void ConfigureServices(IServiceCollection services)
                     opt.ConnectionString = appInsightsCnnStr;
                 });
             }
+
+            services.AddSingleton<IUseCase<string, ApiUser>, ApiKeyService>();
+            services.AddSingleton<ApiUserEnricher>();
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
diff --git a/TramsDataApi/TramsDataApi.csproj b/TramsDataApi/TramsDataApi.csproj
index e3abc3726..d15c3f9a3 100644
--- a/TramsDataApi/TramsDataApi.csproj
+++ b/TramsDataApi/TramsDataApi.csproj
@@ -19,6 +19,8 @@
           <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
         </PackageReference>
         <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="6.0.19" />
+        <PackageReference Include="Serilog.AspNetCore" Version="7.0.0" />
+        <PackageReference Include="Serilog.Sinks.ApplicationInsights" Version="4.0.0" />
         <PackageReference Include="Swashbuckle.AspNetCore" Version="6.5.0" />
         <PackageReference Include="TimeZoneConverter" Version="6.1.0" />
         <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
diff --git a/TramsDataApi/appsettings.json b/TramsDataApi/appsettings.json
index 71bf017c4..8d5b1d1d7 100644
--- a/TramsDataApi/appsettings.json
+++ b/TramsDataApi/appsettings.json
@@ -21,5 +21,21 @@
   "ConnectionStrings": {
     "DefaultConnection": "Server=localhost,1433;Database=sip;User Id=sa;TrustServerCertificate=True;Password=Your_password123"
   },
-  "SyncAcademyConversionProjectsSchedule": "0 0/15 * * * *"
+  "SyncAcademyConversionProjectsSchedule": "0 0/15 * * * *",
+  "Serilog": {
+    "Using": [
+      "Serilog.Sinks.ApplicationInsights"
+    ],
+    "MinimumLevel": {
+      "Default": "Information",
+      "Override": {
+        "Microsoft": "Warning",
+        "System": "Warning"
+      }
+    },
+    "Enrich": [ "FromLogContext" ],
+    "Properties": {
+      "Application": "Dfe.Academies.Api"
+    }
+  }
 }