How to use log4net in Asp.net core 2.0

Question

I configure log4net in my asp.net core 2.0 application as mentioned in this article LINK

program.cs

public static void Main(string[] args) {     var logRepository = LogManager.GetRepository(Assembly.GetEntryAssembly());     XmlConfigurator.Configure(logRepository, new FileInfo("log4net.config"));      BuildWebHost(args).Run(); } 

HomeController

public class HomeController : Controller {     private static readonly log4net.ILog log = log4net.LogManager.GetLogger(typeof(HomeController));      public IActionResult Error()     {         log.Info("Hello logging world!");         return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });     } } 

log4net.config

<?xml version="1.0" encoding="utf-8"?> <configuration>   <log4net>     <root>       <level value="ALL" />       <appender-ref ref="RollingFile" />     </root>     <appender name="RollingFile" type="log4net.Appender.FileAppender">       <file value="‪C:\Temp\app.log" />        <layout type="log4net.Layout.PatternLayout">         <conversionPattern value="%-5p %d{hh:mm:ss} %message%newline" />       </layout>     </appender>   </log4net> </configuration> 

Unlucky!, I didn't see any file generated in ‪C:\Temp\app.log directory. What would be the mistake? how to configure log4net for asp.net core 2.0?

Answer 1

I am successfully able to log a file using the following code

public static void Main(string[] args) {     XmlDocument log4netConfig = new XmlDocument();     log4netConfig.Load(File.OpenRead("log4net.config"));     var repo = log4net.LogManager.CreateRepository(Assembly.GetEntryAssembly(),                typeof(log4net.Repository.Hierarchy.Hierarchy));     log4net.Config.XmlConfigurator.Configure(repo, log4netConfig["log4net"]);      BuildWebHost(args).Run(); } 

log4net.config in website root

<?xml version="1.0" encoding="utf-8" ?> <log4net>   <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">     <lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>     <file value="C:\Temp\" />     <datePattern value="yyyy-MM-dd.'txt'"/>     <staticLogFileName value="false"/>     <appendToFile value="true"/>     <rollingStyle value="Date"/>     <maxSizeRollBackups value="100"/>     <maximumFileSize value="15MB"/>     <layout type="log4net.Layout.PatternLayout">       <conversionPattern value="%date [%thread] %-5level App  %newline %message %newline %newline"/>     </layout>   </appender>     <root>       <level value="ALL"/>       <appender-ref ref="RollingLogFileAppender"/>     </root> </log4net> 

Answer 2

There is a third-party log4net adapter for the ASP.NET Core logging interface.

Only thing you need to do is pass the ILoggerFactory to your Startup class, then call

loggerFactory.AddLog4Net(); 

and have a config in place. So you don't have to write any boiler-plate code.

More info here