feat(example-management): add seq and serilog (#491)

Co-authored-by: Ratan Sunder Parai <ratanparai@gmail.com>

src/Services/ExamManagement/ExamManagement.API/ExamManagement.API.csproj

@@ -5,6 +5,9 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Serilog" Version="2.10.0" />
+    <PackageReference Include="Serilog.Enrichers.Span" Version="1.3.0" />
+    <PackageReference Include="Serilog.Sinks.Console" Version="4.0.0" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.1.4" />
   </ItemGroup>
 

src/Services/ExamManagement/ExamManagement.API/Program.cs

@@ -1,20 +1,74 @@
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Hosting;
+using Serilog;
+using Serilog.Enrichers.Span;
 
 namespace ExamManagement.API
 {
     public class Program
     {
+        public static readonly string Namespace = typeof(Program).Namespace!;
+        public static readonly string AppName = Namespace.Substring(Namespace.LastIndexOf('.', Namespace.LastIndexOf('.') - 1) + 1);
+
+        [System.Diagnostics.CodeAnalysis.SuppressMessage(
+            "Design",
+            "CA1031:Do not catch general exception types",
+            Justification = "Top level all exception catcher")]
         public static void Main(string[] args)
         {
-            CreateHostBuilder(args).Build().Run();
+            Activity.DefaultIdFormat = ActivityIdFormat.W3C;
+
+            var configuration = GetConfiguration();
+
+            Log.Logger = CreateSerilogLogger(configuration);
+            try
+            {
+                Log.Information("Configuring web host ({ApplicationContext})...", AppName);
+                CreateHostBuilder(args).Build().Run();                
+
+                return 0;
+            }
+            catch (Exception ex)
+            {
+                Log.Fatal(ex, "Host terminated unexpectedly");
+                return 1;
+            }
+            finally
+            {
+                Log.CloseAndFlush();
+            }
         }
 
-        public static IHostBuilder CreateHostBuilder(string[] args) =>
+        public static IHostBuilder CreateHostBuilder(IConfiguration configuration,string[] args) =>
             Host.CreateDefaultBuilder(args)
                 .ConfigureWebHostDefaults(webBuilder =>
                 {
                     webBuilder.UseStartup<Startup>();
+                    webBuilder.UseConfiguration(configuration);
+                    webBuilder.UseSerilog();
                 });
+
+        private static ILogger CreateSerilogLogger(IConfiguration configuration)
+        {
+            return new LoggerConfiguration()
+                .MinimumLevel.Verbose()
+                .Enrich.WithProperty("ApplicationContext", AppName)
+                .Enrich.FromLogContext()
+                .Enrich.WithSpan()
+                .WriteTo.Console()
+                .WriteTo.Seq("http://seq")
+                .ReadFrom.Configuration(configuration)
+                .CreateLogger();
+        }
+
+        private static IConfiguration GetConfiguration()
+        {
+            var builder = new ConfigurationBuilder()
+                .SetBasePath(Directory.GetCurrentDirectory())
+                .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
+                .AddEnvironmentVariables();
+
+            return builder.Build();
+        }        
     }
 }

src/Services/ExamManagement/ExamManagement.API/Startup.cs

@@ -4,6 +4,7 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.OpenApi.Models;
+using Serilog;
 
 namespace ExamManagement.API
 {
@@ -27,14 +28,20 @@ public void ConfigureServices(IServiceCollection services)
             });
         }
 
-        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
-        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
+        public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerFactory loggerFactory)
         {
+            var pathBase = Configuration["PATH_BASE"];
+            if (!string.IsNullOrEmpty(pathBase))
+            {
+                loggerFactory.CreateLogger<Startup>().LogInformation("Using PATH BASE '{pathBase}'", pathBase);
+                app.UsePathBase(pathBase);
+            }
+
             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();
-
             }
+            app.UseSerilogRequestLogging();
             app.UseSwagger();
             app.UseSwaggerUI(c => c.SwaggerEndpoint("/swagger/v1/swagger.json", "ExamManagement.API v1"));