In a previous post I showed how we configured a client’s application to use Apache log4net and Azure Application Insights.

I modified the code to allow the Instrumentation Key input via a command line parameter or from the ApplicationInsights.config file.

class Program
{
   private static ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

   static void Main(string[] args)
   {
      if (( args.Length != 0) && (args.Length != 1 ))
      {
         Console.WriteLine("Usage AzureApplicationInsightsClientConsole");
         Console.WriteLine("      AzureApplicationInsightsClientConsole <instrumentationKey>");
         return;
      }

      if (args.Length == 1)
      {
         TelemetryConfiguration.Active.InstrumentationKey = args[0];
      }

      log.Debug("This is a Log4Net Debug message");
      log.Info("This is a Log4Net Info message");
      log.Warn("This is a Log4Net Warning message");
      log.Error("This is an Log4Net Error message");
      log.Fatal("This is a Log4Net Fatal message");

      TelemetryConfiguration.Active.TelemetryChannel.Flush();

      Console.WriteLine("Press <enter> to exit>");
      Console.ReadLine();
   }
}

I updated the Log4Net setup to use the ManagedColoredConsoleAppender which required a couple of modifications to the Log4Net.config file. (I had to remove HighIntensity)

 <appender name="ColoredConsoleAppender" type="log4net.Appender.ManagedColoredConsoleAppender">
      <mapping>
         <level value="ERROR" />
         <foreColor value="White" />
         <backColor value="Red" />
      </mapping>
      <mapping>
         <level value="DEBUG" />
         <backColor value="Green" />
      </mapping>
      <layout type="log4net.Layout.PatternLayout">
         <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
      </layout>
   </appender>

A sample project is available here.