Logging during Application Startup¶

var builder = WebApplication.CreateBuilder(args);

// register LocalTextFileListener
KissLog.KissLogConfiguration.Listeners.Add(new LocalTextFileListener(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "logs"), FlushTrigger.OnMessage));

// create a "Program" logger, used to log code executed during application startup
using var loggerFactory = LoggerFactory.Create(config =>
{
    config
        .AddConfiguration(builder.Configuration.GetSection("Logging"))
        .AddSimpleConsole()
        .AddKissLog(options =>
        {
            options.Formatter = (FormatterArgs args) =>
            {
                if (args.Exception == null)
                    return args.DefaultValue;

                string exceptionStr = new ExceptionFormatter().Format(args.Exception, args.Logger);
                return string.Join(Environment.NewLine, new[] { args.DefaultValue, exceptionStr });
            };
        });
});
var logger = loggerFactory.CreateLogger(nameof(Program));

logger.LogDebug("Executing an important startup code [...]");

try
{
    // simulating an exception during startup code

    int zero = 0;
    var result = 10 / zero;
}
catch (Exception ex)
{
    logger.LogError(ex, "Error executing startup code");
    throw;
}

// code removed for simplicity

app.Run();

using KissLog;
using KissLog.Listeners.FileListener;
using System;

namespace AspNet.Mvc
{
    public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();
            RouteConfig.RegisterRoutes(RouteTable.Routes);

             // register LocalTextFileListener
            KissLogConfiguration.Listeners.Add(new LocalTextFileListener(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "logs"), FlushTrigger.OnMessage));

            Logger logger = new Logger(url: "Application_Start");

            logger.Debug("Executing an important startup code [...]");

            try
            {
                // simulating an exception during startup code

                int zero = 0;
                var result = 10 / zero;
            }
            catch (Exception ex)
            {
                logger.Error(ex);
                throw;
            }
            finally
            {
                Logger.NotifyListeners(logger);
            }
        }

        // [ ... ]
    }
}