using Serilog;
using SerilogWeb.Classic.Enrichers;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Web;
using System.Web.Hosting;

namespace TestSerilog.App_Start
{
  public class SerilogConfig
  {
    public static ILogger CreateLogger()
    {
      var logpath = HostingEnvironment.MapPath("~");
      var config = new LoggerConfiguration()
        .Enrich.WithMachineName()
        .Enrich.WithProperty("ApplicationName", AssemblyTitle)
        .Enrich.With<HttpRequestClientHostIPEnricher>()
        .Enrich.With<HttpRequestRawUrlEnricher>()
        .Enrich.With<HttpRequestIdEnricher>()
        .Enrich.With<UserNameEnricher>()
        //.Enrich.WithProperty("RuntimeVersion", Environment.Version)
        // this ensures that calls to LogContext.PushProperty will cause the logger to be enriched
        .Enrich.FromLogContext()
        .MinimumLevel.Verbose()
        .WriteTo.Seq(ConfigurationManager.AppSettings["SeqServer"], apiKey: ConfigurationManager.AppSettings["SeqApiKey"])
        .WriteTo.RollingFile(Path.Combine(logpath, "Logs\\EricSunTestLog-{Date}.log"), retainedFileCountLimit: null, outputTemplate: "{Timestamp:yyyy-MM-dd HH:mm:ss.fff zzz} [{Level}] {SourceContext} - ({MachineName}|{HttpRequestId}|{UserName}) {Message}{NewLine}{Exception}");
      return config.CreateLogger();
    }

    public static string AssemblyTitle
    {
      get
      {
        var attributes = typeof(SerilogConfig).Assembly.GetCustomAttributes(typeof(AssemblyTitleAttribute), false);
        if (attributes.Length > 0)
        {
          var titleAttribute = (AssemblyTitleAttribute)attributes[0];
          if (titleAttribute.Title.Length > 0)
            return titleAttribute.Title;
        }
        return Path.GetFileNameWithoutExtension(Assembly.GetEntryAssembly().CodeBase);
      }
    }
  }
}

 <appSettings>
  <add key="SeqServer" value="http://localhost:5341/" />
  <add key="SeqApiKey" value="" />
 </appSettings>

using Microsoft.Owin;
using Owin;
using Serilog;
using TestSerilog.App_Start;

[assembly: OwinStartupAttribute(typeof(TestSerilog.Startup))]
namespace TestSerilog
{
  public partial class Startup
  {
    public void Configuration(IAppBuilder app)
    {
      ConfigureAuth(app);
      Log.Logger = SerilogConfig.CreateLogger();
    }
  }
}

using Serilog;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace TestSerilog.Controllers
{
  public class HomeController : Controller
  {
    private ILogger _logger = Log.Logger; 

    public ActionResult Index()
    {
      _logger.Debug("This is index -- debug.");
      _logger.Information("This is index -- information.");
      _logger.Warning("This is index -- warning.");
      _logger.Error("This is index -- error.");
      return View();
    }

    public ActionResult About()
    {
      ViewBag.Message = "Your application description page.";

      return View();
    }

    public ActionResult Contact()
    {
      ViewBag.Message = "Your contact page.";

      return View();
    }
  }
}