osm_mon/core/settings.py

   1 # Copyright 2017 Intel Research and Development Ireland Limited
   2 # *************************************************************
   3
   4 # This file is part of OSM Monitoring module
   5 # All Rights Reserved to Intel Corporation
   6
   7 # Licensed under the Apache License, Version 2.0 (the "License"); you may
   8 # not use this file except in compliance with the License. You may obtain
   9 # a copy of the License at
  10
  11 #         http://www.apache.org/licenses/LICENSE-2.0
  12
  13 # Unless required by applicable law or agreed to in writing, software
  14 # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  15 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  16 # License for the specific language governing permissions and limitations
  17 # under the License.
  18
  19 # For those usages not covered by the Apache License, Version 2.0 please
  20 # contact: helena.mcgough@intel.com or adrian.hoban@intel.com
  21 ##
  22 """Global configuration managed by environment variables."""
  23
  24 import logging
  25 import os
  26
  27 from collections import namedtuple
  28
  29 from osm_mon.core.singleton import Singleton
  30
  31 import six
  32
  33 __author__ = "Helena McGough"
  34
  35 log = logging.getLogger(__name__)
  36
  37
  38 class BadConfigError(Exception):
  39     """Configuration exception."""
  40
  41     pass
  42
  43
  44 class CfgParam(namedtuple('CfgParam', ['key', 'default', 'data_type'])):
  45     """Configuration parameter definition."""
  46
  47     def value(self, data):
  48         """Convert a string to the parameter type."""
  49         try:
  50             return self.data_type(data)
  51         except (ValueError, TypeError):
  52             raise BadConfigError(
  53                 'Invalid value "%s" for configuration parameter "%s"' % (
  54                     data, self.key))
  55
  56
  57 @Singleton
  58 class Config(object):
  59     """Configuration object."""
  60
  61     _configuration = [
  62         CfgParam('BROKER_URI', "localhost:9092", six.text_type),
  63         CfgParam('MONGO_URI', "mongo:27017", six.text_type),
  64         CfgParam('DATABASE', "sqlite:///mon_sqlite.db", six.text_type),
  65         CfgParam('OS_DEFAULT_GRANULARITY', 300, int),
  66         CfgParam('REQUEST_TIMEOUT', 10, int),
  67         CfgParam('OSMMON_LOG_LEVEL', "INFO", six.text_type),
  68         CfgParam('OSMMON_KAFKA_LOG_LEVEL', "WARN", six.text_type),
  69         CfgParam('OSMMON_COLLECTOR_INTERVAL', 30, int),
  70         CfgParam('OSMMON_EVALUATOR_INTERVAL', 30, int),
  71         CfgParam('OSMMON_VCA_HOST', "localhost", six.text_type),
  72         CfgParam('OSMMON_VCA_SECRET', "secret", six.text_type),
  73         CfgParam('OSMMON_VCA_USER', "admin", six.text_type),
  74         CfgParam('OSMMON_DATABASE_COMMONKEY', "changeme", six.text_type),
  75     ]
  76
  77     _config_dict = {cfg.key: cfg for cfg in _configuration}
  78     _config_keys = _config_dict.keys()
  79
  80     def __init__(self):
  81         """Set the default values."""
  82         for cfg in self._configuration:
  83             setattr(self, cfg.key, cfg.default)
  84         self.read_environ()
  85
  86     def read_environ(self):
  87         """Check the appropriate environment variables and update defaults."""
  88         for key in self._config_keys:
  89             try:
  90                 val = self._config_dict[key].data_type(os.environ[key])
  91                 setattr(self, key, val)
  92             except KeyError as exc:
  93                 log.debug("Environment variable not present: %s", exc)
  94         return