You can extend and customize syslog-ng OSE easily by writing destinations, parsers, template functions, and sources in Python.

To debug and troubleshoot your Python code, syslog-ng OSE allows you to use the logger() method to send log messages to the internal() source of syslog-ng OSE. That way the diagnostic messages of your Python code are treated the same way as other such log messages of syslog-ng OSE. This has the following benefits:

• The logger() method respects the log level settings of syslog-ng OSE. You can write error, warning, info, debug, and trace level messages.

• You can follow what your Python code is doing even if syslog-ng OSE is running as a daemon in the background.

Logging to the internal() source is available in syslog-ng OSE version 3.20 and later.

To send log messages to the internal() source from Python

1. Add the following import to your Python code:

   import syslogng

2. Create a logger object:

   logger = syslogng.Logger()

3. Use the logger object in your Python code, for example:

   logger.info("This is a sample log message send from the Python code.")

   You can use the following log levels: logger.error, logger.warning, logger.info, logger.debug, logger.trace

4. Make sure that your syslog-ng OSE configuration includes the internal() source, for example:

   source s_internal { internal(); };
   destination d_internal { file("/var/log/internal.txt"); };
   log {source(s_internal); destination(d_internal); };