centralize a lot of service registration

src/Core/Utilities/LoggerFactoryExtensions.cs

@@ -0,0 +1,39 @@
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Logging;
+using Serilog;
+using Serilog.Events;
+using System;
+
+namespace Bit.Core.Utilities
+{
+    public static class LoggerFactoryExtensions
+    {
+        public static ILoggerFactory AddSerilog(
+            this ILoggerFactory factory,
+            IHostingEnvironment env,
+            IApplicationLifetime appLifetime,
+            GlobalSettings globalSettings,
+            Func<LogEvent, bool> filter = null)
+        {
+            if(env.IsProduction())
+            {
+                if(filter == null)
+                {
+                    filter = (e) => true;
+                }
+
+                var serilog = new LoggerConfiguration()
+                    .Enrich.FromLogContext()
+                    .Filter.ByIncludingOnly(filter)
+                    .WriteTo.AzureDocumentDB(new Uri(globalSettings.DocumentDb.Uri), globalSettings.DocumentDb.Key,
+                        timeToLive: TimeSpan.FromDays(7))
+                    .CreateLogger();
+
+                factory.AddSerilog(serilog);
+                appLifetime.ApplicationStopped.Register(Log.CloseAndFlush);
+            }
+
+            return factory;
+        }
+    }
+}