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
  43 class InfoFilter(logging.Filter):
  44     def filter(self, rec):
  45         return rec.levelno in (logging.DEBUG, logging.INFO)
  46
  47
  48 #
  49 # Logger class definition
  50 #
  51
  52
  53 class Logger(object):
  54     """
  55     Logger class that encapsulates logging functions, internaly it uses Python
  56     logging module with a separated instance instead of global.
  57
  58     Default logging level is 'info'.
  59     """
  60
  61     def __init__(self):
  62         # Create default global logger
  63         self.log_level = logging.INFO
  64         self.logger = logging.Logger("topolog", level=self.log_level)
  65
  66         handler_stdout = logging.StreamHandler(sys.stdout)
  67         handler_stdout.setLevel(logging.DEBUG)
  68         handler_stdout.addFilter(InfoFilter())
  69         handler_stdout.setFormatter(
  70             logging.Formatter(fmt="%(asctime)s %(levelname)s: %(message)s")
  71         )
  72         handler_stderr = logging.StreamHandler()
  73         handler_stderr.setLevel(logging.WARNING)
  74         handler_stderr.setFormatter(
  75             logging.Formatter(fmt="%(asctime)s %(levelname)s: %(message)s")
  76         )
  77
  78         self.logger.addHandler(handler_stdout)
  79         self.logger.addHandler(handler_stderr)
  80
  81         # Handle more loggers
  82         self.loggers = {"topolog": self.logger}
  83
  84     def set_log_level(self, level):
  85         "Set the logging level"
  86         self.log_level = DEBUG_TOPO2LOGGING.get(level)
  87         self.logger.setLevel(self.log_level)
  88
  89     def get_logger(self, name="topolog", log_level=None, target=sys.stdout):
  90         """
  91         Get a new logger entry. Allows creating different loggers for formating,
  92         filtering or handling (file, stream or stdout/stderr).
  93         """
  94         if log_level is None:
  95             log_level = self.log_level
  96         if name in self.loggers:
  97             return self.loggers[name]
  98
  99         nlogger = logging.Logger(name, level=log_level)
 100         if isinstance(target, str):
 101             handler = logging.FileHandler(filename=target)
 102         else:
 103             handler = logging.StreamHandler(stream=target)
 104
 105         handler.setFormatter(
 106             logging.Formatter(fmt="%(asctime)s %(levelname)s: %(message)s")
 107         )
 108         nlogger.addHandler(handler)
 109         self.loggers[name] = nlogger
 110         return nlogger
 111
 112
 113 #
 114 # Global variables
 115 #
 116
 117 logger_config = Logger()
 118 logger = logger_config.logger