Set libvirt environment variables to deactivate logging

import os

import time

import signal

import logging

            if self.loop.role is not None:

                self.loop.close_plugins()

            logger.debug('Role hypervisor affected')

            # set libvirt environement variables

            os.environ['LIBVIRT_DEBUG'] = '4'

            # os.environ['LIBVIRT_LOG_FILTERS'] = ''

            os.environ['LIBVIRT_LOG_OUTPUT'] = '4:stderr'

            # we don't import those modules at the top because some dependancies

            # may not be installed

            from cloudcontrol.node.hypervisor import Handler as HypervisorHandler