Question

I have a application which is loading PlugIn-Modules with reflection.
The Application is defining a log4net-log-appender in the app.config like:

<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
  <file value="logs\xxx.log" />
  <appendToFile value="true" />
  <rollingStyle value="Size" />
  <maxSizeRollBackups value="10" />
  <maximumFileSize value="1MB" />
  <staticLogFileName value="true" />
  <threshold value="DEBUG" />
  <layout type="log4net.Layout.PatternLayout">
    <conversionPattern value="%date [%thread] %-5level %logger{2} - %message%newline" />
  </layout>
</appender>

I get the Logger in the code like:

private static readonly ILog log = LogManager.GetLogger(typeof(Indexer));

Now, I am searching a way to declare different Log-Files for each Module (assembly), which is loaded as PlugIn with reflection.

The first problem is, that the modules are using Business-Library-Classes together (they are in a assembly which is used of all modules) which also generates log-entries. This entries should also be inserted in the log-file of the module.

The second problem is, I don’t know the modules at developing-time. So I cannot insert some config in the app.config.

Answer 1

The second problem is, i don’t know the modules at developing-time. So i cannot insert some config in the app.config.

This reveals that it might not be possible in the config file. When you add a new plugin, you can add code to add a new appender for the plugin.

Hers some (code) to get you inspired:

// Setup RollingFileAppender
  log4net.Appender.RollingFileAppender fileAppender = new log4net.Appender.RollingFileAppender();
  fileAppender.Layout = new log4net.Layout.PatternLayout("%d [%t]%-5p %c [%x] - %m%n");
  fileAppender.MaximumFileSize = "100KB";
  fileAppender.MaxSizeRollBackups = 5;
  fileAppender.RollingStyle = log4net.Appender.RollingFileAppender.RollingMode.Size;
  fileAppender.AppendToFile = true;
  fileAppender.File = fileName;
  fileAppender.Name = "XXXRollingFileAppender";
  log4net.Config.BasicConfigurator.Configure(fileAppender);

You need to add that it is only from the plugin-assembly you want to log, and maybe omit them from the already configures RollingFileAppender.