1ff8469ef7
The Oslo libraries have moved all of their code out of the 'oslo' namespace package into per-library packages. The namespace package was retained during kilo for backwards compatibility, but will be removed by the liberty-2 milestone. This change removes the use of the namespace package, replacing it with the new package names. The patches in the libraries will be put on hold until application patches have landed, or L2, whichever comes first. At that point, new versions of the libraries without namespace packages will be released as a major version update. Please merge this patch, or an equivalent, before L2 to avoid problems with those library releases. Blueprint: remove-namespace-packages https://blueprints.launchpad.net/oslo-incubator/+spec/remove-namespace-packages Change-Id: Iae62b48993eef3b31420f8cc245a55f5e303c4fc
149 lines
4.0 KiB
Python
149 lines
4.0 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 stevedore import extension
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from oslo_config import cfg
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from oslo_log import log as logging
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LOG = logging.getLogger(__name__)
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CONF = cfg.CONF
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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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@classmethod
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def get_cfg_opts(cls):
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"""Get any static configuration options
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Returns an array of tuples in the form:
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[(group1, [Option1, Option2]), (group2, [Option1, Option2])]
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"""
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return []
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@classmethod
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def get_extra_cfg_opts(cls):
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"""Get any dynamically built configuration options
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Returns an array of tuples in the form:
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[(group1, [Option1, Option2]), (group2, [Option1, Option2])]
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"""
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return []
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@classmethod
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def register_cfg_opts(cls, namespace):
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mgr = extension.ExtensionManager(namespace)
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for e in mgr:
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for group, opts in e.plugin.get_cfg_opts():
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if isinstance(group, six.string_types):
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group = cfg.OptGroup(name=group)
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CONF.register_group(group)
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CONF.register_opts(opts, group=group)
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@classmethod
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def register_extra_cfg_opts(cls, namespace):
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mgr = extension.ExtensionManager(namespace)
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for e in mgr:
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for group, opts in e.plugin.get_extra_cfg_opts():
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if isinstance(group, six.string_types):
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group = cfg.OptGroup(name=group)
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CONF.register_group(group)
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CONF.register_opts(opts, group=group)
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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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