Log4Net and GAC - How to reference Configuraition Files?

Question

Hello all

I am using log4net during my development, as as part of a project constraint, I now need to add it to the Global Assembly Cache.

The logging definitions are in a file Log4Net.xml. That file is referenced in my assemblyinfo as: [assembly: log4net.Config.XmlConfigurator(ConfigFile = "Log4Net.xml", Watch = true)]. So long as the xml file was in the same directory as the log4net.dll, everything has been working fine.

However now that I've added log4net to the GAC, it is no longer picking up the xml file.

Does anyone know what I need to change in order to have it pick up the XML file again? Is hardcoding the patch in the assembly reference the only way?

Many thanks

Answer 1

You might ensure that your log4net.xml file is set to "Copy Always" (Right Click on log4net.xml -> Properties -> Copy to Output Directory = Copy always). To ensure that your config file is being copied, you should check your bin\debug or bin\release directory and verify that the log4net.xml file exists in the same directory that your application executes.

If that doesn't workthen you can try enabling internal debugging in log4net. To enable internal debugging, add the following key to your app.config file. This will send internal log4net debug messages to your Visual Studio Output window (View -> Output).

<configuration>
  <appSettings>
    <add key="log4net.Internal.Debug" value="true"/>
  </appSettings>
</configuration>

For more information on log4net's internal debugging, you might check Phil Haack's blog post here.

If all else fails, you can turn on internal debugging and explicitly load the configuration by calling log4net's XmlConfigurator.ConfigureAndWatch method.

var fi = new FileInfo(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location) + "\\log4net.xml");
XmlConfigurator.ConfigureAndWatch(fi);

Answer 2

log4net expects the config file to be in the path returned by:

 System.AppDomain.CurrentDomain.BaseDirectory

Let your application print this information to some file and then you know where you need to place the config file.

Of course there are other solutions, but then you cannot use the attribute anymore. Calling the ConfigureAndWatch() method directly allows you to figure out yourself where the config file is; you can even decide on a location (does not have to be a hard-coded path).