# Copyright 2015 Rackspace
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import abc
import json
import os
from six.moves import configparser
from six import add_metaclass
from cafe.common.reporting import cclogging
try:
from cafe.engine.mongo.client import BaseMongoClient
except:
""" We are temporarily ignoring errors due to plugin refactor.
The mongo data-source is currently not being used. and needs to be
abstracted out into a data-source plugin.
"""
pass
[docs]class ConfigDataException(Exception):
pass
[docs]class NonExistentConfigPathError(Exception):
pass
[docs]class ConfigEnvironmentVariableError(Exception):
pass
# This is a decorator
[docs]def expected_values(*values):
def decorator(fn):
def wrapped():
class UnexpectedConfigOptionValueError(Exception):
pass
value = fn()
if value not in values:
raise UnexpectedConfigOptionValueError(value)
return fn()
return wrapped
return decorator
def _get_path_from_env(os_env_var):
try:
return os.environ[os_env_var]
except KeyError:
msg = "'{0}' environment variable was not set.".format(
os_env_var)
raise ConfigEnvironmentVariableError(msg)
except Exception as exception:
print(
"Unexpected exception when attempting to access '{1}'"
" environment variable.".format(os_env_var))
raise exception
# Standard format to for flat key/value data sources
CONFIG_KEY = 'CAFE_{section_name}_{key}'
[docs]@add_metaclass(abc.ABCMeta)
class DataSource(object):
def __init__(self):
self._log = cclogging.logging.getLogger(
cclogging.get_object_namespace(self.__class__))
[docs] def get(self, item_name, default=None):
raise NotImplementedError
[docs] def get_raw(self, item_name, default=None):
raise NotImplementedError
[docs] def get_boolean(self, item_name, default=None):
raise NotImplementedError
[docs] def get_json(self, item_name, default=None):
raise NotImplementedError
@staticmethod
def _str_to_bool(value):
"""Attempts to convert a text value to a boolean.
Returns None otherwise."""
if value:
return value.lower() == 'true'
return None
@staticmethod
def _parse_json(value, log=None):
"""Parse the value as JSON. Returns None if value is invalid JSON."""
if not value:
return None
try:
return json.loads(value)
except ValueError as error:
if log is not None:
log.warning("Invalid JSON '{0}'. ValueError: {1}"
.format(value, error))
return None
[docs]class EnvironmentVariableDataSource(DataSource):
def __init__(self, section_name):
super(EnvironmentVariableDataSource, self).__init__()
self._section_name = section_name
[docs] def get(self, item_name, default=None):
return os.environ.get(CONFIG_KEY.format(
section_name=self._section_name, key=item_name), default)
[docs] def get_raw(self, item_name, default=None):
return self.get(item_name, default)
[docs] def get_boolean(self, item_name, default=None):
return self._str_to_bool(self.get(item_name, default))
[docs] def get_json(self, item_name, default=None):
return self._parse_json(self.get(item_name, default), log=self._log)
[docs]class ConfigParserDataSource(DataSource):
def __init__(self, config_file_path, section_name):
super(ConfigParserDataSource, self).__init__()
cafe_env_var = {key: value for key, value in os.environ.items()
if key.startswith('CAFE_')}
self._data_source = configparser.SafeConfigParser(
defaults=cafe_env_var)
self._section_name = section_name
# Check if the path exists
if not os.path.exists(config_file_path):
msg = 'Could not verify the existence of config file at {0}'\
.format(config_file_path)
raise NonExistentConfigPathError(msg)
# Read the file in and turn it into a SafeConfigParser instance
try:
self._data_source.read(config_file_path)
except Exception as exception:
self._log.exception(exception)
raise exception
[docs] def get(self, item_name, default=None):
try:
return self._data_source.get(self._section_name, item_name)
except (configparser.NoOptionError, configparser.NoSectionError) as e:
if default is None:
self._log.error(str(e))
else:
msg = "{0}. Using default value '{1}' instead".format(
str(e), default)
self._log.warning(msg)
return default
[docs] def get_raw(self, item_name, default=None):
try:
return self._data_source.get(
self._section_name, item_name, raw=True)
except (configparser.NoOptionError, configparser.NoSectionError) as e:
if default is None:
self._log.error(str(e))
else:
msg = "{0}. Using default value '{1}' instead".format(
str(e), default)
self._log.warning(msg)
return default
[docs] def get_boolean(self, item_name, default=None):
try:
return self._data_source.getboolean(self._section_name, item_name)
except (configparser.NoOptionError, configparser.NoSectionError) as e:
if default is None:
self._log.error(str(e))
else:
msg = "{0}. Using default value '{1}' instead".format(
str(e), default)
self._log.warning(msg)
return default
[docs] def get_json(self, item_name, default=None):
value = self._parse_json(self.get(item_name, None), log=self._log)
if value is None:
return default
return value
[docs]class DictionaryDataSource(DataSource):
[docs] def get(self, item_name, default=None):
section = self._data_source.get(self._section_name)
if section is None:
self._log.error("No section: '{section_name}'".format(
section_name=self._section_name))
return None
if item_name not in section:
self._log.error(
"No option '{item_name}' in section: '{section_name}'".format(
section_name=self._section_name, item_name=item_name))
return default
return section.get(item_name, default)
[docs] def get_raw(self, item_name, default=None):
section = self._data_source.get(self._section_name)
if section is None:
self._log.error("No section: '{section_name}'".format(
section_name=self._section_name))
return None
if item_name not in section:
self._log.error(
"No option '{item_name}' in section: '{section_name}'".format(
section_name=self._section_name, item_name=item_name))
return default
return section.get(item_name, default)
[docs] def get_boolean(self, item_name, default=None):
section = self._data_source.get(self._section_name)
if section is None:
self._log.error("No section: '{section_name}'".format(
section_name=self._section_name))
return None
if item_name not in section:
self._log.error(
"No option '{item_name}' in section: '{section_name}'".format(
section_name=self._section_name, item_name=item_name))
return default
return self._str_to_bool(self.get(item_name, default))
[docs] def get_json(self, item_name, default=None):
value = self._parse_json(self.get(item_name, None), log=self._log)
if value is None:
return default
return value
[docs]class JSONDataSource(DictionaryDataSource):
def __init__(self, config_file_path, section_name):
super(JSONDataSource, self).__init__()
self._section_name = section_name
# Check if file path exists
if not os.path.exists(config_file_path):
msg = 'Could not verify the existence of config file at {0}'\
.format(config_file_path)
raise NonExistentConfigPathError(msg)
with open(config_file_path) as config_file:
config_data = config_file.read()
try:
self._data_source = json.loads(config_data)
except Exception as exception:
self._log.exception(exception)
raise exception
[docs]class MongoDataSource(DictionaryDataSource):
def __init__(
self, hostname, db_name, username, password, config_name,
section_name):
super(MongoDataSource, self).__init__()
self._section_name = section_name
self.db = BaseMongoClient(
hostname=hostname, db_name=db_name,
username=username, password=password)
self.db.connect()
self.db.auth()
self._data_source = self.db.find_one({'config_name': config_name})
[docs]class BaseConfigSectionInterface(object):
"""Base class for building an interface for the data contained in a
SafeConfigParser object, as loaded from the config file as defined
by the engine's config file.
"""
def __init__(self, config_file_path, section_name):
self._log = cclogging.logging.getLogger(
cclogging.get_object_namespace(self.__class__))
self._override = EnvironmentVariableDataSource(
section_name)
self._data_source = ConfigParserDataSource(
config_file_path, section_name)
self._section_name = section_name
[docs] def get(self, item_name, default=None):
return self._override.get(item_name, None) or \
self._data_source.get(item_name, default)
[docs] def get_raw(self, item_name, default=None):
return self._override.get_raw(item_name, None) or \
self._data_source.get_raw(item_name, default)
[docs] def get_boolean(self, item_name, default=None):
value = self._override.get_boolean(item_name, None)
if value is None:
value = self._data_source.get_boolean(item_name, default)
return value
[docs] def get_json(self, item_name, default=None):
value = self._override.get_json(item_name, None)
if value is None:
value = self._data_source.get_json(item_name, default)
return value
[docs]class ConfigSectionInterface(BaseConfigSectionInterface):
def __init__(self, config_file_path=None, section_name=None):
section_name = (section_name or
getattr(self, 'SECTION_NAME', None) or
getattr(self, 'CONFIG_SECTION_NAME', None))
config_file_path = config_file_path or _get_path_from_env(
'CAFE_CONFIG_FILE_PATH')
super(ConfigSectionInterface, self).__init__(
config_file_path, section_name)