Per-Instance logging with NLog & TopShelf

Program.cs

using System;
using System.Timers;
using FubuCore;
using NLog;
using NLog.Layouts;
using NLog.Targets;
using Topshelf;
using Topshelf.Runtime;

namespace Dragon.WindowsService
{
    public class TownCrier
    {
        readonly Timer _timer;
        public TownCrier(HostSettings settings)
        {
            _timer = new Timer(1000) { AutoReset = true };
            _timer.Elapsed += (sender, eventArgs) => Console.WriteLine("It is {0} and all is well", DateTime.Now);
        }
        public void Start() { _timer.Start(); }

        public bool Stop(HostControl hostControl)
        {
            _timer.Stop();
            return true;
        }

        public void ShutDown(HostControl control)
        {
            Stop(control);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            HostFactory.Run(x =>
            {
                x.Service<TownCrier>(s =>
                {
                    s.ConstructUsing(settings =>
                    {
                        ReconfigureNLog(settings);
                        return new TownCrier(settings);
                    });
                    s.WhenStarted(tc => tc.Start());
                    s.WhenStopped((tc, control) => tc.Stop(control));
                    s.WhenShutdown((tc, control) => tc.ShutDown(control));
                });

                x.RunAsLocalSystem();

                x.UseNLog();

                x.SetDescription("Sample Topshelf Host");
                x.SetDisplayName("Stuff");
                x.SetServiceName("Stuff");
            });
        }

        private static void ReconfigureNLog(HostSettings settings)
        {
            var target = LogManager.Configuration.FindTargetByName("file") as FileTarget;
            if (target != null && string.IsNullOrWhiteSpace(settings.InstanceName) == false)
            {
                var customLogFileName = "log.{0}.".ToFormat(settings.ServiceName);
                target.FileName = (target.FileName as SimpleLayout).Text.Replace("log.", customLogFileName);
                target.ArchiveFileName = (target.ArchiveFileName as SimpleLayout).Text.Replace("log.", customLogFileName);
                LogManager.ReconfigExistingLoggers();
            }
        }
    }
}