Source code for glance.common.location_strategy.store_type

# Copyright 2014 IBM Corp.
# All Rights Reserved.
#    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
#    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.

"""Storage preference based location strategy module"""

import urllib.parse as urlparse

from oslo_config import cfg

from glance.i18n import _

store_type_opts = [
Preference order of storage backends.

Provide a comma separated list of store names in the order in
which images should be retrieved from storage backends.
These store names must be registered with the ``stores``
configuration option.

NOTE: The ``store_type_preference`` configuration option is applied
only if ``store_type`` is chosen as a value for the
``location_strategy`` configuration option. An empty list will not
change the location order.

Possible values:
    * Empty list
    * Comma separated list of registered store names. Legal values are:
        * file
        * http
        * rbd
        * swift
        * cinder
        * vmware

Related options:
    * location_strategy
    * stores


CONF.register_opts(store_type_opts, group='store_type_location_strategy')


[docs] def get_strategy_name(): """Return strategy module name.""" return 'store_type'
[docs] def init(): """Initialize strategy module.""" # NOTE(zhiyan): We have a plan to do a reusable glance client library for # all clients like Nova and Cinder in near period, it would be able to # contains common code to provide uniform image service interface for them, # just like Brick in Cinder, this code can be moved to there and shared # between Glance and client both side. So this implementation as far as # possible to prevent make relationships with Glance(server)-specific code, # for example: using functions within store module to validate # 'store_type_preference' option. mapping = {'file': ['file', 'filesystem'], 'http': ['http', 'https'], 'rbd': ['rbd'], 'swift': ['swift', 'swift+https', 'swift+http'], 'cinder': ['cinder'], 'vmware': ['vsphere']} _STORE_TO_SCHEME_MAP.clear() _STORE_TO_SCHEME_MAP.update(mapping)
[docs] def get_ordered_locations(locations, uri_key='url', **kwargs): """ Order image location list. :param locations: The original image location list. :param uri_key: The key name for location URI in image location dictionary. :returns: The image location list with preferred store type order. """ def _foreach_store_type_preference(): store_types = CONF.store_type_location_strategy.store_type_preference for preferred_store in store_types: preferred_store = str(preferred_store).strip() if not preferred_store: continue yield preferred_store if not locations: return locations preferences = {} others = [] for preferred_store in _foreach_store_type_preference(): preferences[preferred_store] = [] for location in locations: uri = location.get(uri_key) if not uri: continue pieces = urlparse.urlparse(uri.strip()) store_name = None for store, schemes in _STORE_TO_SCHEME_MAP.items(): if pieces.scheme.strip() in schemes: store_name = store break if store_name in preferences: preferences[store_name].append(location) else: others.append(location) ret = [] # NOTE(zhiyan): While configuration again since py26 does not support # ordereddict container. for preferred_store in _foreach_store_type_preference(): ret.extend(preferences[preferred_store]) ret.extend(others) return ret