Logging - Allow external log4net config file

[ferventcoder]

If choco finds a log file next to it by the name of log4net.config.xml (a little bit different on purpose), it will use that file instead of the built-in configuration for log4net. Use this with caution as it could cause certain logging items to disappear when the external config does not include the necessary logging sections. It may even cause choco to error.

[ferventcoder]

Start out by placing this: https://github.com/chocolatey/choco/blob/master/src/chocolatey/infrastructure/logging/log4net.config.xml as a file next to choco in $env:ChocolateyInstall (the choco.exe here is the one you want).

Then convert the ManagedColoredConsoleAppenders to just ConsoleAppenders. https://logging.apache.org/log4net/release/sdk/html/T_log4net_Appender_ConsoleAppender.htm

Something like (not fully tested out, but it appears to work):

<?xml version="1.0"?>
<!-- For colors that can be used with ManagedColoredConsoleAppender, see
     http://msdn.microsoft.com/en-us/library/system.consolecolor(v=vs.110).aspx 
-->
<log4net>
  <appender name="NormalLoggingColoredConsoleAppender" type="log4net.Appender.ConsoleAppender">
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%message%newline" />
    </layout>
    <filter type="log4net.Filter.LevelRangeFilter">
      <param name="LevelMin" value="INFO" />
      <param name="LevelMax" value="FATAL" />
    </filter>
  </appender>

  <appender name="ImportantLoggingColoredConsoleAppender" type="log4net.Appender.ConsoleAppender">
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%message%newline" />
    </layout>
    <filter type="log4net.Filter.LevelRangeFilter">
      <param name="LevelMin" value="INFO" />
      <param name="LevelMax" value="FATAL" />
    </filter>
  </appender>

  <appender name="VerboseLoggingColoredConsoleAppender" type="log4net.Appender.ConsoleAppender">
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%message%newline" />
    </layout>
    <filter type="log4net.Filter.LevelRangeFilter">
      <param name="LevelMin" value="ERROR" />
      <param name="LevelMax" value="FATAL" />
    </filter>
  </appender> 
  
  <appender name="TraceLoggingColoredConsoleAppender" type="log4net.Appender.ConsoleAppender">
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%message%newline" />
    </layout>
    <filter type="log4net.Filter.LevelRangeFilter">
      <param name="LevelMin" value="FATAL" />
      <param name="LevelMax" value="FATAL" />
    </filter>
  </appender>
  
  <root>
    <level value="DEBUG" />
  </root>

  <logger name="Important">
    <level value="DEBUG" />
    <appender-ref ref="ImportantLoggingColoredConsoleAppender" />
  </logger>  
  
  <logger name="Verbose">
    <level value="DEBUG" />
    <appender-ref ref="VerboseLoggingColoredConsoleAppender" />
  </logger>  
  
  <logger name="Trace">
    <level value="DEBUG" />
    <appender-ref ref="TraceLoggingColoredConsoleAppender" />
  </logger>

  <logger name="chocolatey">
    <level value="DEBUG"/>
    <appender-ref ref="NormalLoggingColoredConsoleAppender" />
  </logger>  
  
  <logger name="LogFileOnly">
    <level value="DEBUG"/>
  </logger>
</log4net>

NOTE: It's best NOT to rename the appenders as Chocolatey needs to use those names internally.

[ferventcoder]