tools/helpers/logging.py

   1 # Copyright 2021 Oliver Smith
   2 # SPDX-License-Identifier: GPL-3.0-or-later
   3 import logging
   4 from logging.handlers import RotatingFileHandler
   5 import os
   6 import sys
   7
   8
   9 class stdout_logger(logging.StreamHandler):
  10     """
  11     Write to stdout and to the already opened log file.
  12     """
  13     _args = None
  14
  15     def emit(self, record):
  16         # INFO or higher: Write to stdout
  17         if self._args.quiet or (
  18                 record.levelno < logging.INFO and
  19                 not self._args.details_to_stdout):
  20             return
  21
  22         try:
  23             msg = self.format(record)
  24             stream = self.stream
  25             stream.write(msg)
  26             stream.write(self.terminator)
  27             self.flush()
  28
  29         except (KeyboardInterrupt, SystemExit):
  30             raise
  31         except BaseException:
  32             self.handleError(record)
  33
  34
  35 def add_verbose_log_level():
  36     """
  37     Add a new log level "verbose", which is below "debug". Also monkeypatch
  38     logging, so it can be used with logging.verbose().
  39
  40     This function is based on work by Voitek Zylinski and sleepycal:
  41     https://stackoverflow.com/a/20602183
  42     All stackoverflow user contributions are licensed as CC-BY-SA:
  43     https://creativecommons.org/licenses/by-sa/3.0/
  44     """
  45     logging.VERBOSE = 5
  46     logging.addLevelName(logging.VERBOSE, "VERBOSE")
  47     logging.Logger.verbose = lambda inst, msg, * \
  48         args, **kwargs: inst.log(logging.VERBOSE, msg, *args, **kwargs)
  49     logging.verbose = lambda msg, *args, **kwargs: logging.log(logging.VERBOSE,
  50                                                                msg, *args,
  51                                                                **kwargs)
  52
  53
  54 def init(args):
  55     root_logger = logging.getLogger()
  56     root_logger.handlers = []
  57
  58     # Set log level
  59     add_verbose_log_level()
  60     root_logger.setLevel(logging.DEBUG)
  61     if args.verbose:
  62         root_logger.setLevel(logging.VERBOSE)
  63
  64     # Add custom stdout log handler
  65     handler = stdout_logger()
  66     handler._args = args
  67     handler.setFormatter(logging.Formatter("[%(asctime)s] %(message)s",
  68                                   datefmt="%H:%M:%S"))
  69     root_logger.addHandler(handler)
  70
  71     # Add file log handler
  72     if args.action == "container" and not args.details_to_stdout:
  73         os.chmod(args.log, 0o644)
  74         handler = RotatingFileHandler(args.log, maxBytes=5*1024*1024, backupCount=1)
  75         handler.setFormatter(logging.Formatter("(%(process)d) [%(asctime)s] %(message)s",
  76                                       datefmt="%a, %d %b %Y %H:%M:%S"))
  77         root_logger.addHandler(handler)
  78
  79 def disable():
  80     logger = logging.getLogger()
  81     logger.disabled = True