Python logging.Handler for use in external Metasploit modules.

log_handler.py

import logging
import metasploit.module as module

class MetasploitLogHandler(logging.Handler):
    def emit(self, record):
        log_entry = self.format(record)
        level = 'debug'
        if record.levelno >= logging.ERROR:
            level = 'error'
        elif record.levelno >= logging.WARNING:
            level = 'warning'
        elif record.levelno >= logging.INFO:
            level = 'info'
        module.log(log_entry, level)
        return

    @classmethod
    def setup(cls, level=logging.DEBUG):
        logger = logging.getLogger()
        if level is not None:
            logger.setLevel(level)
        handler = cls()
        logger.addHandler(handler)
        return handler

MetasploitLogHandler.setup()

Just as a note to all who use this:
Metasploit has some difficulties if there are newlines in the message to be logged. To solve the problem, you can do something like this:

for msplit in message.splitlines():
   logging.info(msplit )