Setting up log4net in ASP.NET MVC

I seem to burn far to many hours trying to do the relatively simple task of setting up log4net on a project. Well step one is easy enough, install through nuget. Next...

Add web.config settings

I like to create a separate config file for log4net because it keeps things simpler. So add the following config:

	<configSections>
	<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
	</configSections>
	<!-- more config -->
	<log4net configSource="log4net.config" />

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Add the log4net config file

Next add a file called log4net to your solution and add the following config. This is a good starting point, logging to a file and also to the console. There is ALOT of config options for log4net, but this is a good starting point:

	<?xml version="1.0" encoding="utf-8"?>
	<log4net>
	<!-- Log to vs output window -->
	<appender name="TraceAppender" type="log4net.Appender.TraceAppender" >
	<layout type="log4net.Layout.PatternLayout">
	<conversionPattern value="%timestamp [%level] %-60message %newline" />
	</layout>
	</appender>
	<!-- Log to console app window -->
	<appender name="Console" type="log4net.Appender.ConsoleAppender">
	<layout type="log4net.Layout.PatternLayout">
	<conversionPattern value="%message%newline" />
	</layout>
	</appender>
	<!-- Log to a file -->
	<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
	<file value="Logs\log.log" />
	<appendToFile value="true" />
	<rollingStyle value="Size" />
	<maxSizeRollBackups value="10" />
	<maximumFileSize value="1MB" />
	<staticLogFileName value="true" />
	<layout type="log4net.Layout.PatternLayout">
	<conversionPattern value="%date [%thread] %level %logger - %message%newline" />
	</layout>
	</appender>
	<root>
	<level value="ALL" />
	<appender-ref ref="TraceAppender" />
	<appender-ref ref="Console" />
	<appender-ref ref="RollingFileAppender"/>
	</root>
	</log4net>

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Don't forget to set the log4net.config file to Copy Local in visual studio properties window.

Initalise the xml config

This is the bit I always forget. One line of code you stick somewhere in your app startup to get log4net to initialise using the xml configuration we just added;

	public class MvcApplication : System.Web.HttpApplication
	{
	protected void Application_Start()
	{
	// Configure log4net
	log4net.Config.XmlConfigurator.Configure();
	}
	}

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Write log statements

Now we are free to make full use of the log4net logging capabilities. First declare a logger at the top of the class, then log away:

	private static readonly ILog _logger = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
	public ActionResult Index()
	{
	_logger.Info("Displaying the home page");
	return View();
	}

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Finally if you are using the Visual Studio output window, its worth knowing that you can right click and turn off the white noise: