heat-translator/translator/conf/config.py
Julio Ruano 3f98139a7e Allow for dynamic class loading of target types
Tosca types need to be mapped to corresponding target translation
types (i.e. HOT). This commit allows for the target types to be
dynamically loaded from a directory. It allows for more flexibility
by pulling types from a known directory instead of defining each
individiual type statically in the code. For example, with this
commit you no longer need a separate import for each target type.

Also, this commit adds the notion of a global configuration object
that can be shared throughout the translator. The configuration
defines the location directory for custom defined target types.
This configuration can be set by the user in the corresponding
translator/conf/translator.conf file. In the future, additional
values can be added to this configuration and the code can be
extended to support them, but only the required values were
implemented here.

Change-Id: If7b8da12eef5b8ed8a2e11b1f412203d4ed59c5a
Implements: blueprint dynamic-tosca-to-hot-map
2015-09-28 12:09:02 -05:00

68 lines
2.3 KiB
Python

#
# 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.
''' Provide a global configuration for the TOSCA translator'''
from six.moves import configparser
from toscaparser.utils.gettextutils import _
import translator.common.exception as exception
class ConfigProvider(object):
'''Global config proxy that wraps a ConfigParser object.
Allows for class based access to config values. Should only be initialized
once using the corresponding translator.conf file in the conf directory.
'''
# List that captures all of the conf file sections.
# Append any new sections to this list.
_sections = ['DEFAULT']
_translator_config = None
@classmethod
def _load_config(cls, conf_file):
'''Private method only to be called once from the __init__ module'''
cls._translator_config = configparser.ConfigParser()
try:
cls._translator_config.read(conf_file)
except configparser.ParsingError:
msg = _('Unable to parse translator.conf file.'
'Check to see that it exists in the conf directory.')
raise exception.ConfFileParseError(message=msg)
@classmethod
def get_value(cls, section, key):
try:
value = cls._translator_config.get(section, key)
except configparser.NoOptionError:
raise exception.ConfOptionNotDefined(key=key, section=section)
except configparser.NoSectionError:
raise exception.ConfSectionNotDefined(section=section)
return value
@classmethod
def get_all_values(cls):
values = []
for section in cls._sections:
try:
values.extend(cls._translator_config.items(section=section))
except configparser.NoOptionError:
raise exception.ConfSectionNotDefined(section=section)
return values