6652bcc842
* [H401] Docstrings should not start with a space. Change-Id: I1e98718a6612aea04453904fa4eca892a1dd1744
103 lines
2.7 KiB
Python
103 lines
2.7 KiB
Python
# Copyright 2012 Bouvet ASA
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#
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# Author: Endre Karlson <endre.karlson@bouvet.no>
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import abc
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import six
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from stevedore import driver
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from stevedore import enabled
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from designate.openstack.common import log as logging
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LOG = logging.getLogger(__name__)
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@six.add_metaclass(abc.ABCMeta)
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class Plugin(object):
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__plugin_ns__ = None
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__plugin_name__ = None
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__plugin_type__ = None
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def __init__(self):
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self.name = self.get_canonical_name()
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LOG.debug("Loaded plugin %s" % self.name)
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@classmethod
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def get_canonical_name(cls):
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"""
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Return the plugin name
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"""
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type_ = cls.get_plugin_type()
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name = cls.get_plugin_name()
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return "%s:%s" % (type_, name)
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@classmethod
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def get_plugin_name(cls):
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return cls.__plugin_name__
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@classmethod
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def get_plugin_type(cls):
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return cls.__plugin_type__
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class DriverPlugin(Plugin):
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"""
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A Driver plugin is a singleton, where only a single driver will loaded
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at a time.
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For example: Storage implementations (SQLAlchemy)
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"""
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@classmethod
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def get_driver(cls, name):
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"""Load a single driver"""
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LOG.debug('Looking for driver %s in %s' % (name, cls.__plugin_ns__))
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mgr = driver.DriverManager(cls.__plugin_ns__, name)
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return mgr.driver
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class ExtensionPlugin(Plugin):
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"""
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Extension plugins are loaded as a group, where multiple extensions will
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be loaded and used at the same time.
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For example: Designate Sink handlers
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"""
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@classmethod
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def get_extensions(cls, enabled_extensions=None):
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"""Load a series of extensions"""
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LOG.debug('Looking for extensions in %s' % cls.__plugin_ns__)
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def _check_func(ext):
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if enabled_extensions is None:
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# All extensions are enabled by default, if no specific list
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# is specified
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return True
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return ext.plugin.get_plugin_name() in enabled_extensions
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mgr = enabled.EnabledExtensionManager(
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cls.__plugin_ns__, check_func=_check_func,
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propagate_map_exceptions=True)
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return [e.plugin for e in mgr]
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