tests/topotests/lib/topolog.py

   1 #
   2 # topolog.py
   3 # Library of helper functions for NetDEF Topology Tests
   4 #
   5 # Copyright (c) 2017 by
   6 # Network Device Education Foundation, Inc. ("NetDEF")
   7 #
   8 # Permission to use, copy, modify, and/or distribute this software
   9 # for any purpose with or without fee is hereby granted, provided
  10 # that the above copyright notice and this permission notice appear
  11 # in all copies.
  12 #
  13 # THE SOFTWARE IS PROVIDED "AS IS" AND NETDEF DISCLAIMS ALL WARRANTIES
  14 # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  15 # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NETDEF BE LIABLE FOR
  16 # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
  17 # DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  18 # WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  19 # ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  20 # OF THIS SOFTWARE.
  21 #
  22
  23 """
  24 Logging utilities for topology tests.
  25
  26 This file defines our logging abstraction.
  27 """
  28
  29 import sys
  30 import logging
  31
  32 # Helper dictionary to convert Topogen logging levels to Python's logging.
  33 DEBUG_TOPO2LOGGING = {
  34     'debug': logging.DEBUG,
  35     'info': logging.INFO,
  36     'output': logging.INFO,
  37     'warning': logging.WARNING,
  38     'error': logging.ERROR,
  39     'critical': logging.CRITICAL,
  40 }
  41
  42 class InfoFilter(logging.Filter):
  43     def filter(self, rec):
  44         return rec.levelno in (logging.DEBUG, logging.INFO)
  45
  46 #
  47 # Logger class definition
  48 #
  49
  50 class Logger(object):
  51     """
  52     Logger class that encapsulates logging functions, internaly it uses Python
  53     logging module with a separated instance instead of global.
  54
  55     Default logging level is 'info'.
  56     """
  57
  58     def __init__(self):
  59         # Create default global logger
  60         self.log_level = logging.INFO
  61         self.logger = logging.Logger('topolog', level=self.log_level)
  62
  63         handler_stdout = logging.StreamHandler(sys.stdout)
  64         handler_stdout.setLevel(logging.DEBUG)
  65         handler_stdout.addFilter(InfoFilter())
  66         handler_stdout.setFormatter(
  67             logging.Formatter(fmt='%(asctime)s %(levelname)s: %(message)s')
  68         )
  69         handler_stderr = logging.StreamHandler()
  70         handler_stderr.setLevel(logging.WARNING)
  71         handler_stderr.setFormatter(
  72             logging.Formatter(fmt='%(asctime)s %(levelname)s: %(message)s')
  73         )
  74
  75         self.logger.addHandler(handler_stdout)
  76         self.logger.addHandler(handler_stderr)
  77
  78         # Handle more loggers
  79         self.loggers = {'topolog': self.logger}
  80
  81     def set_log_level(self, level):
  82         "Set the logging level"
  83         self.log_level = DEBUG_TOPO2LOGGING.get(level)
  84         self.logger.setLevel(self.log_level)
  85
  86     def get_logger(self, name='topolog', log_level=None, target=sys.stdout):
  87         """
  88         Get a new logger entry. Allows creating different loggers for formating,
  89         filtering or handling (file, stream or stdout/stderr).
  90         """
  91         if log_level is None:
  92             log_level = self.log_level
  93         if self.loggers.has_key(name):
  94             return self.loggers[name]
  95
  96         nlogger = logging.Logger(name, level=log_level)
  97         if isinstance(target, str):
  98             handler = logging.FileHandler(filename=target)
  99         else:
 100             handler = logging.StreamHandler(stream=target)
 101
 102         handler.setFormatter(
 103             logging.Formatter(fmt='%(asctime)s %(levelname)s: %(message)s')
 104         )
 105         nlogger.addHandler(handler)
 106         self.loggers[name] = nlogger
 107         return nlogger
 108
 109 #
 110 # Global variables
 111 #
 112
 113 logger_config = Logger()
 114 logger = logger_config.logger