extra = {'hostname': socket.gethostname(), 'ip': socket.gethostbyname(socket.gethostname()), 'user': getpass.getuser()}


def get_logger():
    logging.basicConfig(
        format='%(asctime)s # %(user)s # %(hostname)s # %(ip)s # %(message)s',
        datefmt='%m/%d/%Y %I:%M:%S')

    crawler_logger = logging.getLogger("crawler")
    crawler_logger.setLevel(logging.INFO)
    crawler_logger = logging.LoggerAdapter(crawler_logger, extra)
    return crawler_logger

logger.warning("Harmful URL # Potentially harmful url # %s" % url["url"])

logger.info("URL already exists: %s ", url_dict["url"])

logger.error("ERROR # ERROR while crawling url. %s" % e)

--- Logging error ---
Traceback (most recent call last):
  File "/usr/lib/python3.6/logging/__init__.py", line 992, in emit
    msg = self.format(record)
  File "/usr/lib/python3.6/logging/__init__.py", line 838, in format
    return fmt.format(record)
  File "/usr/lib/python3.6/logging/__init__.py", line 578, in format
    s = self.formatMessage(record)
  File "/usr/lib/python3.6/logging/__init__.py", line 547, in formatMessage
    return self._style.format(record)
  File "/usr/lib/python3.6/logging/__init__.py", line 391, in format
    return self._fmt % record.__dict__
KeyError: 'user'