4ff0723479
The quantum/api/v2/views.py module is replaced by is_visible properties in the RESOURCE_ATTRIBUTE_MAP defined in quantum/api/v2/attributes.py. Extensions are given the ability to add extended attribute descriptions to this map during initialization, allowing extended attributes to be implemented similarly to core attributes in plugins. Resolves bug 1023111. Change-Id: Ic6e224d5d841b6a1d4d1c762d7306adaf91f7a2d
582 lines
20 KiB
Python
582 lines
20 KiB
Python
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright 2011 OpenStack LLC.
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# Copyright 2011 Justin Santa Barbara
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# All Rights Reserved.
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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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from abc import ABCMeta
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import imp
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import logging
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import os
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import routes
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import webob.dec
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import webob.exc
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from quantum.common import exceptions
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import quantum.extensions
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from quantum.manager import QuantumManager
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from quantum.openstack.common import cfg
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from quantum import wsgi
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LOG = logging.getLogger('quantum.api.extensions')
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class PluginInterface(object):
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__metaclass__ = ABCMeta
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@classmethod
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def __subclasshook__(cls, klass):
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"""
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The __subclasshook__ method is a class method
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that will be called everytime a class is tested
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using issubclass(klass, PluginInterface).
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In that case, it will check that every method
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marked with the abstractmethod decorator is
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provided by the plugin class.
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"""
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for method in cls.__abstractmethods__:
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if any(method in base.__dict__ for base in klass.__mro__):
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continue
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return NotImplemented
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return True
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class ExtensionDescriptor(object):
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"""Base class that defines the contract for extensions.
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Note that you don't have to derive from this class to have a valid
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extension; it is purely a convenience.
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"""
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def get_name(self):
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"""The name of the extension.
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e.g. 'Fox In Socks'
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"""
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raise NotImplementedError()
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def get_alias(self):
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"""The alias for the extension.
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e.g. 'FOXNSOX'
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"""
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raise NotImplementedError()
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def get_description(self):
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"""Friendly description for the extension.
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e.g. 'The Fox In Socks Extension'
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"""
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raise NotImplementedError()
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def get_namespace(self):
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"""The XML namespace for the extension.
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e.g. 'http://www.fox.in.socks/api/ext/pie/v1.0'
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"""
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raise NotImplementedError()
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def get_updated(self):
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"""The timestamp when the extension was last updated.
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e.g. '2011-01-22T13:25:27-06:00'
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"""
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# NOTE(justinsb): Not sure of the purpose of this is, vs the XML NS
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raise NotImplementedError()
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def get_resources(self):
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"""List of extensions.ResourceExtension extension objects.
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Resources define new nouns, and are accessible through URLs.
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"""
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resources = []
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return resources
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def get_actions(self):
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"""List of extensions.ActionExtension extension objects.
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Actions are verbs callable from the API.
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"""
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actions = []
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return actions
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def get_request_extensions(self):
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"""List of extensions.RequestException extension objects.
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Request extensions are used to handle custom request data.
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"""
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request_exts = []
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return request_exts
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def get_extended_attributes(self, version):
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"""Map describing extended attributes for core resources.
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Extended attributes are implemented by a core plugin similarly
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to the attributes defined in the core, and can appear in
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request and response messages. Their names are scoped with the
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extension's prefix. The core API version is passed to this
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function, which must return a
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map[<resource_name>][<attribute_name>][<attribute_property>]
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specifying the extended resource attribute properties required
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by that API version.
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"""
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return {}
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def get_plugin_interface(self):
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"""
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Returns an abstract class which defines contract for the plugin.
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The abstract class should inherit from extesnions.PluginInterface,
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Methods in this abstract class should be decorated as abstractmethod
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"""
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return None
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class ActionExtensionController(wsgi.Controller):
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def __init__(self, application):
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self.application = application
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self.action_handlers = {}
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def add_action(self, action_name, handler):
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self.action_handlers[action_name] = handler
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def action(self, request, id):
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input_dict = self._deserialize(request.body,
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request.get_content_type())
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for action_name, handler in self.action_handlers.iteritems():
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if action_name in input_dict:
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return handler(input_dict, request, id)
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# no action handler found (bump to downstream application)
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response = self.application
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return response
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class RequestExtensionController(wsgi.Controller):
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def __init__(self, application):
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self.application = application
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self.handlers = []
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def add_handler(self, handler):
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self.handlers.append(handler)
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def process(self, request, *args, **kwargs):
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res = request.get_response(self.application)
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# currently request handlers are un-ordered
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for handler in self.handlers:
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response = handler(request, res)
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return response
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class ExtensionController(wsgi.Controller):
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def __init__(self, extension_manager):
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self.extension_manager = extension_manager
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def _translate(self, ext):
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ext_data = {}
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ext_data['name'] = ext.get_name()
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ext_data['alias'] = ext.get_alias()
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ext_data['description'] = ext.get_description()
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ext_data['namespace'] = ext.get_namespace()
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ext_data['updated'] = ext.get_updated()
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ext_data['links'] = [] # TODO(dprince): implement extension links
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return ext_data
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def index(self, request):
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extensions = []
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for _alias, ext in self.extension_manager.extensions.iteritems():
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extensions.append(self._translate(ext))
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return dict(extensions=extensions)
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def show(self, request, id):
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# NOTE(dprince): the extensions alias is used as the 'id' for show
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ext = self.extension_manager.extensions.get(id, None)
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if not ext:
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raise webob.exc.HTTPNotFound(
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_("Extension with alias %s does not exist") % id)
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return self._translate(ext)
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def delete(self, request, id):
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raise webob.exc.HTTPNotFound()
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def create(self, request):
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raise webob.exc.HTTPNotFound()
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class ExtensionMiddleware(wsgi.Middleware):
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"""Extensions middleware for WSGI."""
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def __init__(self, application,
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ext_mgr=None):
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self.ext_mgr = (ext_mgr
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or ExtensionManager(
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get_extensions_path()))
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mapper = routes.Mapper()
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# extended resources
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for resource in self.ext_mgr.get_resources():
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LOG.debug(_('Extended resource: %s'),
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resource.collection)
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for action, method in resource.collection_actions.iteritems():
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path_prefix = ""
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parent = resource.parent
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conditions = dict(method=[method])
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path = "/%s/%s" % (resource.collection, action)
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if parent:
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path_prefix = "/%s/{%s_id}" % (parent["collection_name"],
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parent["member_name"])
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with mapper.submapper(controller=resource.controller,
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action=action,
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path_prefix=path_prefix,
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conditions=conditions) as submap:
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submap.connect(path)
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submap.connect("%s.:(format)" % path)
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mapper.resource(resource.collection, resource.collection,
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controller=resource.controller,
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member=resource.member_actions,
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parent_resource=resource.parent)
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# extended actions
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action_controllers = self._action_ext_controllers(application,
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self.ext_mgr, mapper)
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for action in self.ext_mgr.get_actions():
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LOG.debug(_('Extended action: %s'), action.action_name)
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controller = action_controllers[action.collection]
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controller.add_action(action.action_name, action.handler)
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# extended requests
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req_controllers = self._request_ext_controllers(application,
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self.ext_mgr, mapper)
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for request_ext in self.ext_mgr.get_request_extensions():
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LOG.debug(_('Extended request: %s'), request_ext.key)
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controller = req_controllers[request_ext.key]
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controller.add_handler(request_ext.handler)
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self._router = routes.middleware.RoutesMiddleware(self._dispatch,
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mapper)
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super(ExtensionMiddleware, self).__init__(application)
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@classmethod
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def factory(cls, global_config, **local_config):
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"""Paste factory."""
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def _factory(app):
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return cls(app, global_config, **local_config)
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return _factory
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def _action_ext_controllers(self, application, ext_mgr, mapper):
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"""Return a dict of ActionExtensionController-s by collection."""
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action_controllers = {}
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for action in ext_mgr.get_actions():
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if not action.collection in action_controllers.keys():
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controller = ActionExtensionController(application)
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mapper.connect("/%s/:(id)/action.:(format)" %
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action.collection,
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action='action',
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controller=controller,
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conditions=dict(method=['POST']))
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mapper.connect("/%s/:(id)/action" % action.collection,
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action='action',
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controller=controller,
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conditions=dict(method=['POST']))
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action_controllers[action.collection] = controller
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return action_controllers
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def _request_ext_controllers(self, application, ext_mgr, mapper):
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"""Returns a dict of RequestExtensionController-s by collection."""
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request_ext_controllers = {}
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for req_ext in ext_mgr.get_request_extensions():
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if not req_ext.key in request_ext_controllers.keys():
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controller = RequestExtensionController(application)
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mapper.connect(req_ext.url_route + '.:(format)',
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action='process',
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controller=controller,
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conditions=req_ext.conditions)
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mapper.connect(req_ext.url_route,
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action='process',
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controller=controller,
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conditions=req_ext.conditions)
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request_ext_controllers[req_ext.key] = controller
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return request_ext_controllers
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@webob.dec.wsgify(RequestClass=wsgi.Request)
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def __call__(self, req):
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"""Route the incoming request with router."""
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req.environ['extended.app'] = self.application
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return self._router
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@staticmethod
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@webob.dec.wsgify(RequestClass=wsgi.Request)
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def _dispatch(req):
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"""Dispatch the request.
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Returns the routed WSGI app's response or defers to the extended
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application.
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"""
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match = req.environ['wsgiorg.routing_args'][1]
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if not match:
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return req.environ['extended.app']
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app = match['controller']
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return app
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def plugin_aware_extension_middleware_factory(global_config, **local_config):
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"""Paste factory."""
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def _factory(app):
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ext_mgr = PluginAwareExtensionManager.get_instance()
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return ExtensionMiddleware(app, ext_mgr=ext_mgr)
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return _factory
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class ExtensionManager(object):
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"""Load extensions from the configured extension path.
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See tests/unit/extensions/foxinsocks.py for an
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example extension implementation.
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"""
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def __init__(self, path):
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LOG.info(_('Initializing extension manager.'))
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self.path = path
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self.extensions = {}
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self._load_all_extensions()
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def get_resources(self):
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"""Returns a list of ResourceExtension objects."""
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resources = []
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resources.append(ResourceExtension('extensions',
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ExtensionController(self)))
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for ext in self.extensions.itervalues():
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try:
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resources.extend(ext.get_resources())
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except AttributeError:
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# NOTE(dprince): Extension aren't required to have resource
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# extensions
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pass
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return resources
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def get_actions(self):
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"""Returns a list of ActionExtension objects."""
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actions = []
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for ext in self.extensions.itervalues():
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try:
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actions.extend(ext.get_actions())
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except AttributeError:
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# NOTE(dprince): Extension aren't required to have action
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# extensions
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pass
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return actions
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def get_request_extensions(self):
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"""Returns a list of RequestExtension objects."""
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request_exts = []
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for ext in self.extensions.itervalues():
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try:
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request_exts.extend(ext.get_request_extensions())
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except AttributeError:
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# NOTE(dprince): Extension aren't required to have request
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# extensions
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pass
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return request_exts
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def extend_resources(self, version, attr_map):
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"""Extend resources with additional attributes."""
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for ext in self.extensions.itervalues():
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try:
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extended_attrs = ext.get_extended_attributes(version)
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for resource, resource_attrs in extended_attrs.iteritems():
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attr_map[resource].update(resource_attrs)
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except AttributeError:
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# Extensions aren't required to have extended
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# attributes
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pass
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def _check_extension(self, extension):
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"""Checks for required methods in extension objects."""
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try:
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LOG.debug(_('Ext name: %s'), extension.get_name())
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LOG.debug(_('Ext alias: %s'), extension.get_alias())
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LOG.debug(_('Ext description: %s'), extension.get_description())
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LOG.debug(_('Ext namespace: %s'), extension.get_namespace())
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LOG.debug(_('Ext updated: %s'), extension.get_updated())
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except AttributeError as ex:
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LOG.exception(_("Exception loading extension: %s"), unicode(ex))
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return False
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return True
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def _load_all_extensions(self):
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"""Load extensions from the configured path.
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Load extensions from the configured path. The extension name is
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constructed from the module_name. If your extension module was named
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widgets.py the extension class within that module should be
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'Widgets'.
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See tests/unit/extensions/foxinsocks.py for an example
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extension implementation.
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"""
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for path in self.path.split(':'):
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if os.path.exists(path):
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self._load_all_extensions_from_path(path)
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else:
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LOG.error("Extension path \"%s\" doesn't exist!" % path)
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def _load_all_extensions_from_path(self, path):
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for f in os.listdir(path):
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try:
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LOG.info(_('Loading extension file: %s'), f)
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mod_name, file_ext = os.path.splitext(os.path.split(f)[-1])
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ext_path = os.path.join(path, f)
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if file_ext.lower() == '.py' and not mod_name.startswith('_'):
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mod = imp.load_source(mod_name, ext_path)
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ext_name = mod_name[0].upper() + mod_name[1:]
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new_ext_class = getattr(mod, ext_name, None)
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if not new_ext_class:
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LOG.warn(_('Did not find expected name '
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'"%(ext_name)s" in %(file)s'),
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{'ext_name': ext_name,
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'file': ext_path})
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continue
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new_ext = new_ext_class()
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self.add_extension(new_ext)
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except Exception as exception:
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LOG.warn("extension file %s wasnt loaded due to %s",
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f, exception)
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def add_extension(self, ext):
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# Do nothing if the extension doesn't check out
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if not self._check_extension(ext):
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return
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alias = ext.get_alias()
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LOG.warn(_('Loaded extension: %s'), alias)
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if alias in self.extensions:
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raise exceptions.Error("Found duplicate extension: %s" %
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alias)
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self.extensions[alias] = ext
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class PluginAwareExtensionManager(ExtensionManager):
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_instance = None
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def __init__(self, path, plugin):
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self.plugin = plugin
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super(PluginAwareExtensionManager, self).__init__(path)
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def _check_extension(self, extension):
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"""Checks if plugin supports extension and implements the
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extension contract."""
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extension_is_valid = super(PluginAwareExtensionManager,
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self)._check_extension(extension)
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return (extension_is_valid and
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self._plugin_supports(extension) and
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self._plugin_implements_interface(extension))
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def _plugin_supports(self, extension):
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alias = extension.get_alias()
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supports_extension = (hasattr(self.plugin,
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"supported_extension_aliases") and
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alias in self.plugin.supported_extension_aliases)
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if not supports_extension:
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LOG.warn("extension %s not supported by plugin %s",
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alias, self.plugin)
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return supports_extension
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def _plugin_implements_interface(self, extension):
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if(not hasattr(extension, "get_plugin_interface") or
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extension.get_plugin_interface() is None):
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return True
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plugin_has_interface = isinstance(self.plugin,
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extension.get_plugin_interface())
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if not plugin_has_interface:
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LOG.warn("plugin %s does not implement extension's"
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"plugin interface %s" % (self.plugin,
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extension.get_alias()))
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return plugin_has_interface
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@classmethod
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def get_instance(cls):
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if cls._instance is None:
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cls._instance = cls(get_extensions_path(),
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QuantumManager.get_plugin())
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return cls._instance
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|
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class RequestExtension(object):
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"""Extend requests and responses of core Quantum OpenStack API controllers.
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Provide a way to add data to responses and handle custom request data
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that is sent to core Quantum OpenStack API controllers.
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"""
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def __init__(self, method, url_route, handler):
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self.url_route = url_route
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self.handler = handler
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self.conditions = dict(method=[method])
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self.key = "%s-%s" % (method, url_route)
|
|
|
|
|
|
class ActionExtension(object):
|
|
"""Add custom actions to core Quantum OpenStack API controllers."""
|
|
|
|
def __init__(self, collection, action_name, handler):
|
|
self.collection = collection
|
|
self.action_name = action_name
|
|
self.handler = handler
|
|
|
|
|
|
class ResourceExtension(object):
|
|
"""Add top level resources to the OpenStack API in Quantum."""
|
|
|
|
def __init__(self, collection, controller, parent=None,
|
|
collection_actions={}, member_actions={}):
|
|
self.collection = collection
|
|
self.controller = controller
|
|
self.parent = parent
|
|
self.collection_actions = collection_actions
|
|
self.member_actions = member_actions
|
|
|
|
|
|
# Returns the extention paths from a config entry and the __path__
|
|
# of quantum.extensions
|
|
def get_extensions_path():
|
|
paths = ':'.join(quantum.extensions.__path__)
|
|
if cfg.CONF.api_extensions_path:
|
|
paths = ':'.join([cfg.CONF.api_extensions_path, paths])
|
|
|
|
return paths
|