# Copyright 2010-2011 OpenStack Foundation # 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 # # 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. import logging from oslo_config import cfg from oslo_utils import encodeutils import six from stevedore import driver from stevedore import extension from glance_store import capabilities from glance_store import exceptions from glance_store.i18n import _ from glance_store import location CONF = cfg.CONF LOG = logging.getLogger(__name__) _STORE_OPTS = [ cfg.ListOpt('stores', default=['file', 'http'], help=_(""" List of enabled Glance stores. Register the storage backends to use for storing disk images as a comma separated list. The default stores enabled for storing disk images with Glance are ``file`` and ``http``. Possible values: * A comma separated list that could include: * file * http * swift * rbd * sheepdog * cinder * vmware Related Options: * default_store """)), cfg.StrOpt('default_store', default='file', choices=('file', 'filesystem', 'http', 'https', 'swift', 'swift+http', 'swift+https', 'swift+config', 'rbd', 'sheepdog', 'cinder', 'vsphere'), help=_(""" The default scheme to use for storing images. Provide a string value representing the default scheme to use for storing images. If not set, Glance uses ``file`` as the default scheme to store images with the ``file`` store. NOTE: The value given for this configuration option must be a valid scheme for a store registered with the ``stores`` configuration option. Possible values: * file * filesystem * http * https * swift * swift+http * swift+https * swift+config * rbd * sheepdog * cinder * vsphere Related Options: * stores """)), cfg.IntOpt('store_capabilities_update_min_interval', default=0, min=0, help=_(""" Minimum interval in seconds to execute updating dynamic storage capabilities based on current backend status. Provide an integer value representing time in seconds to set the minimum interval before an update of dynamic storage capabilities for a storage backend can be attempted. Setting ``store_capabilities_update_min_interval`` does not mean updates occur periodically based on the set interval. Rather, the update is performed at the elapse of this interval set, if an operation of the store is triggered. By default, this option is set to zero and is disabled. Provide an integer value greater than zero to enable this option. NOTE: For more information on store capabilities and their updates, please visit: https://specs.openstack.org/openstack/glance-specs/\ specs/kilo/store-capabilities.html For more information on setting up a particular store in your deployment and help with the usage of this feature, please contact the storage driver maintainers listed here: http://docs.openstack.org/developer/glance_store/drivers/index.html Possible values: * Zero * Positive integer Related Options: * None """)), ] _STORE_CFG_GROUP = 'glance_store' def _list_opts(): driver_opts = [] mgr = extension.ExtensionManager('glance_store.drivers') # NOTE(zhiyan): Handle available drivers entry_points provided # NOTE(nikhil): Return a sorted list of drivers to ensure that the sample # configuration files generated by oslo config generator retain the order # in which the config opts appear across different runs. If this order of # config opts is not preserved, some downstream packagers may see a long # diff of the changes though not relevant as only order has changed. See # some more details at bug 1619487. drivers = sorted([ext.name for ext in mgr]) handled_drivers = [] # Used to handle backwards-compatible entries for store_entry in drivers: driver_cls = _load_store(None, store_entry, False) if driver_cls and driver_cls not in handled_drivers: if getattr(driver_cls, 'OPTIONS', None) is not None: driver_opts += driver_cls.OPTIONS handled_drivers.append(driver_cls) # NOTE(zhiyan): This separated approach could list # store options before all driver ones, which easier # to read and configure by operator. return ([(_STORE_CFG_GROUP, _STORE_OPTS)] + [(_STORE_CFG_GROUP, driver_opts)]) def register_opts(conf): opts = _list_opts() for group, opt_list in opts: LOG.debug("Registering options for group %s" % group) for opt in opt_list: conf.register_opt(opt, group=group) class Indexable(object): """Indexable for file-like objs iterators Wrapper that allows an iterator or filelike be treated as an indexable data structure. This is required in the case where the return value from Store.get() is passed to Store.add() when adding a Copy-From image to a Store where the client library relies on eventlet GreenSockets, in which case the data to be written is indexed over. """ def __init__(self, wrapped, size): """ Initialize the object :param wrappped: the wrapped iterator or filelike. :param size: the size of data available """ self.wrapped = wrapped self.size = int(size) if size else (wrapped.len if hasattr(wrapped, 'len') else 0) self.cursor = 0 self.chunk = None def __iter__(self): """ Delegate iteration to the wrapped instance. """ for self.chunk in self.wrapped: yield self.chunk def __getitem__(self, i): """ Index into the next chunk (or previous chunk in the case where the last data returned was not fully consumed). :param i: a slice-to-the-end """ start = i.start if isinstance(i, slice) else i if start < self.cursor: return self.chunk[(start - self.cursor):] self.chunk = self.another() if self.chunk: self.cursor += len(self.chunk) return self.chunk def another(self): """Implemented by subclasses to return the next element.""" raise NotImplementedError def getvalue(self): """ Return entire string value... used in testing """ return self.wrapped.getvalue() def __len__(self): """ Length accessor. """ return self.size def _load_store(conf, store_entry, invoke_load=True): try: LOG.debug("Attempting to import store %s", store_entry) mgr = driver.DriverManager('glance_store.drivers', store_entry, invoke_args=[conf], invoke_on_load=invoke_load) return mgr.driver except RuntimeError as e: LOG.warning("Failed to load driver %(driver)s. The " "driver will be disabled" % dict(driver=str([driver, e]))) def _load_stores(conf): for store_entry in set(conf.glance_store.stores): try: # FIXME(flaper87): Don't hide BadStoreConfiguration # exceptions. These exceptions should be propagated # to the user of the library. store_instance = _load_store(conf, store_entry) if not store_instance: continue yield (store_entry, store_instance) except exceptions.BadStoreConfiguration: continue def create_stores(conf=CONF): """ Registers all store modules and all schemes from the given config. Duplicates are not re-registered. """ store_count = 0 for (store_entry, store_instance) in _load_stores(conf): try: schemes = store_instance.get_schemes() store_instance.configure(re_raise_bsc=False) except NotImplementedError: continue if not schemes: raise exceptions.BackendException('Unable to register store %s. ' 'No schemes associated with it.' % store_entry) else: LOG.debug("Registering store %s with schemes %s", store_entry, schemes) scheme_map = {} loc_cls = store_instance.get_store_location_class() for scheme in schemes: scheme_map[scheme] = { 'store': store_instance, 'location_class': loc_cls, 'store_entry': store_entry } location.register_scheme_map(scheme_map) store_count += 1 return store_count def verify_default_store(): scheme = CONF.glance_store.default_store try: get_store_from_scheme(scheme) except exceptions.UnknownScheme: msg = _("Store for scheme %s not found") % scheme raise RuntimeError(msg) def get_known_schemes(): """Returns list of known schemes.""" return location.SCHEME_TO_CLS_MAP.keys() def get_store_from_scheme(scheme): """ Given a scheme, return the appropriate store object for handling that scheme. """ if scheme not in location.SCHEME_TO_CLS_MAP: raise exceptions.UnknownScheme(scheme=scheme) scheme_info = location.SCHEME_TO_CLS_MAP[scheme] store = scheme_info['store'] if not store.is_capable(capabilities.BitMasks.DRIVER_REUSABLE): # Driver instance isn't stateless so it can't # be reused safely and need recreation. store_entry = scheme_info['store_entry'] store = _load_store(store.conf, store_entry, invoke_load=True) store.configure() try: scheme_map = {} loc_cls = store.get_store_location_class() for scheme in store.get_schemes(): scheme_map[scheme] = { 'store': store, 'location_class': loc_cls, 'store_entry': store_entry } location.register_scheme_map(scheme_map) except NotImplementedError: scheme_info['store'] = store return store def get_store_from_uri(uri): """ Given a URI, return the store object that would handle operations on the URI. :param uri: URI to analyze """ scheme = uri[0:uri.find('/') - 1] return get_store_from_scheme(scheme) def get_from_backend(uri, offset=0, chunk_size=None, context=None): """Yields chunks of data from backend specified by uri.""" loc = location.get_location_from_uri(uri, conf=CONF) store = get_store_from_uri(uri) return store.get(loc, offset=offset, chunk_size=chunk_size, context=context) def get_size_from_backend(uri, context=None): """Retrieves image size from backend specified by uri.""" loc = location.get_location_from_uri(uri, conf=CONF) store = get_store_from_uri(uri) return store.get_size(loc, context=context) def delete_from_backend(uri, context=None): """Removes chunks of data from backend specified by uri.""" loc = location.get_location_from_uri(uri, conf=CONF) store = get_store_from_uri(uri) return store.delete(loc, context=context) def get_store_from_location(uri): """ Given a location (assumed to be a URL), attempt to determine the store from the location. We use here a simple guess that the scheme of the parsed URL is the store... :param uri: Location to check for the store """ loc = location.get_location_from_uri(uri, conf=CONF) return loc.store_name def check_location_metadata(val, key=''): if isinstance(val, dict): for key in val: check_location_metadata(val[key], key=key) elif isinstance(val, list): ndx = 0 for v in val: check_location_metadata(v, key='%s[%d]' % (key, ndx)) ndx = ndx + 1 elif not isinstance(val, six.text_type): raise exceptions.BackendException(_("The image metadata key %(key)s " "has an invalid type of %(type)s. " "Only dict, list, and unicode are " "supported.") % dict(key=key, type=type(val))) def store_add_to_backend(image_id, data, size, store, context=None, verifier=None): """ A wrapper around a call to each stores add() method. This gives glance a common place to check the output :param image_id: The image add to which data is added :param data: The data to be stored :param size: The length of the data in bytes :param store: The store to which the data is being added :param context: The request context :param verifier: An object used to verify signatures for images :return: The url location of the file, the size amount of data, the checksum of the data the storage systems metadata dictionary for the location """ (location, size, checksum, metadata) = store.add(image_id, data, size, context=context, verifier=verifier) if metadata is not None: if not isinstance(metadata, dict): msg = (_("The storage driver %(driver)s returned invalid " " metadata %(metadata)s. This must be a dictionary type") % dict(driver=str(store), metadata=str(metadata))) LOG.error(msg) raise exceptions.BackendException(msg) try: check_location_metadata(metadata) except exceptions.BackendException as e: e_msg = (_("A bad metadata structure was returned from the " "%(driver)s storage driver: %(metadata)s. %(e)s.") % dict(driver=encodeutils.exception_to_unicode(store), metadata=encodeutils.exception_to_unicode(metadata), e=encodeutils.exception_to_unicode(e))) LOG.error(e_msg) raise exceptions.BackendException(e_msg) return (location, size, checksum, metadata) def add_to_backend(conf, image_id, data, size, scheme=None, context=None, verifier=None): if scheme is None: scheme = conf['glance_store']['default_store'] store = get_store_from_scheme(scheme) return store_add_to_backend(image_id, data, size, store, context, verifier) def set_acls(location_uri, public=False, read_tenants=[], write_tenants=None, context=None): if write_tenants is None: write_tenants = [] loc = location.get_location_from_uri(location_uri, conf=CONF) scheme = get_store_from_location(location_uri) store = get_store_from_scheme(scheme) try: store.set_acls(loc, public=public, read_tenants=read_tenants, write_tenants=write_tenants, context=context) except NotImplementedError: LOG.debug(_("Skipping store.set_acls... not implemented."))