# Copyright (C) 2013 Deutsche Telekom AG # 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. """Base class for all backup drivers.""" import abc from oslo_config import cfg from oslo_log import log as logging from oslo_serialization import jsonutils import six from cinder.db import base from cinder import exception from cinder.i18n import _, _LI, _LW from cinder import keymgr service_opts = [ cfg.IntOpt('backup_metadata_version', default=2, help='Backup metadata version to be used when backing up ' 'volume metadata. If this number is bumped, make sure the ' 'service doing the restore supports the new version.'), cfg.IntOpt('backup_object_number_per_notification', default=10, help='The number of chunks or objects, for which one ' 'Ceilometer notification will be sent'), cfg.IntOpt('backup_timer_interval', default=120, help='Interval, in seconds, between two progress notifications ' 'reporting the backup status'), ] CONF = cfg.CONF CONF.register_opts(service_opts) LOG = logging.getLogger(__name__) class BackupMetadataAPI(base.Base): TYPE_TAG_VOL_BASE_META = 'volume-base-metadata' TYPE_TAG_VOL_META = 'volume-metadata' TYPE_TAG_VOL_GLANCE_META = 'volume-glance-metadata' def __init__(self, context, db_driver=None): super(BackupMetadataAPI, self).__init__(db_driver) self.context = context @staticmethod def _is_serializable(value): """Returns True if value is serializable.""" try: jsonutils.dumps(value) except TypeError: LOG.info(_LI("Value with type=%s is not serializable"), type(value)) return False return True def _save_vol_base_meta(self, container, volume_id): """Save base volume metadata to container. This will fetch all fields from the db Volume object for volume_id and save them in the provided container dictionary. """ type_tag = self.TYPE_TAG_VOL_BASE_META LOG.debug("Getting metadata type '%s'", type_tag) meta = self.db.volume_get(self.context, volume_id) if meta: container[type_tag] = {} for key, value in meta: # Exclude fields that are "not JSON serializable" if not self._is_serializable(value): LOG.info(_LI("Unable to serialize field '%s' - excluding " "from backup"), key) continue # Copy the encryption key uuid for backup if key is 'encryption_key_id' and value is not None: value = keymgr.API().copy_key(self.context, value) LOG.debug("Copying encryption key uuid for backup.") container[type_tag][key] = value LOG.debug("Completed fetching metadata type '%s'", type_tag) else: LOG.debug("No metadata type '%s' available", type_tag) def _save_vol_meta(self, container, volume_id): """Save volume metadata to container. This will fetch all fields from the db VolumeMetadata object for volume_id and save them in the provided container dictionary. """ type_tag = self.TYPE_TAG_VOL_META LOG.debug("Getting metadata type '%s'", type_tag) meta = self.db.volume_metadata_get(self.context, volume_id) if meta: container[type_tag] = {} for entry in meta: # Exclude fields that are "not JSON serializable" if not self._is_serializable(meta[entry]): LOG.info(_LI("Unable to serialize field '%s' - excluding " "from backup"), entry) continue container[type_tag][entry] = meta[entry] LOG.debug("Completed fetching metadata type '%s'", type_tag) else: LOG.debug("No metadata type '%s' available", type_tag) def _save_vol_glance_meta(self, container, volume_id): """Save volume Glance metadata to container. This will fetch all fields from the db VolumeGlanceMetadata object for volume_id and save them in the provided container dictionary. """ type_tag = self.TYPE_TAG_VOL_GLANCE_META LOG.debug("Getting metadata type '%s'", type_tag) try: meta = self.db.volume_glance_metadata_get(self.context, volume_id) if meta: container[type_tag] = {} for entry in meta: # Exclude fields that are "not JSON serializable" if not self._is_serializable(entry.value): LOG.info(_LI("Unable to serialize field '%s' - " "excluding from backup"), entry) continue container[type_tag][entry.key] = entry.value LOG.debug("Completed fetching metadata type '%s'", type_tag) except exception.GlanceMetadataNotFound: LOG.debug("No metadata type '%s' available", type_tag) @staticmethod def _filter(metadata, fields): """Returns set of metadata restricted to required fields. If fields is empty list, the full set is returned. """ if not fields: return metadata subset = {} for field in fields: if field in metadata: subset[field] = metadata[field] else: LOG.debug("Excluding field '%s'", field) return subset def _restore_vol_base_meta(self, metadata, volume_id, fields): """Restore values to Volume object for provided fields.""" LOG.debug("Restoring volume base metadata") # Ignore unencrypted backups. key = 'encryption_key_id' if key in fields and key in metadata and metadata[key] is not None: self._restore_vol_encryption_meta(volume_id, metadata['volume_type_id']) metadata = self._filter(metadata, fields) self.db.volume_update(self.context, volume_id, metadata) def _restore_vol_encryption_meta(self, volume_id, src_volume_type_id): """Restores the volume_type_id for encryption if needed. Only allow restoration of an encrypted backup if the destination volume has the same volume type as the source volume. Otherwise encryption will not work. If volume types are already the same, no action is needed. """ dest_vol = self.db.volume_get(self.context, volume_id) if dest_vol['volume_type_id'] != src_volume_type_id: LOG.debug("Volume type id's do not match.") # If the volume types do not match, and the destination volume # does not have a volume type, force the destination volume # to have the encrypted volume type, provided it still exists. if dest_vol['volume_type_id'] is None: try: self.db.volume_type_get( self.context, src_volume_type_id) except exception.VolumeTypeNotFound: LOG.debug("Volume type of source volume has been " "deleted. Encrypted backup restore has " "failed.") msg = _("The source volume type '%s' is not " "available.") % (src_volume_type_id) raise exception.EncryptedBackupOperationFailed(msg) # Update dest volume with src volume's volume_type_id. LOG.debug("The volume type of the destination volume " "will become the volume type of the source " "volume.") self.db.volume_update(self.context, volume_id, {'volume_type_id': src_volume_type_id}) else: # Volume type id's do not match, and destination volume # has a volume type. Throw exception. LOG.warning(_LW("Destination volume type is different from " "source volume type for an encrypted volume. " "Encrypted backup restore has failed.")) msg = (_("The source volume type '%(src)s' is different " "than the destination volume type '%(dest)s'.") % {'src': src_volume_type_id, 'dest': dest_vol['volume_type_id']}) raise exception.EncryptedBackupOperationFailed(msg) def _restore_vol_meta(self, metadata, volume_id, fields): """Restore values to VolumeMetadata object for provided fields.""" LOG.debug("Restoring volume metadata") metadata = self._filter(metadata, fields) self.db.volume_metadata_update(self.context, volume_id, metadata, True) def _restore_vol_glance_meta(self, metadata, volume_id, fields): """Restore values to VolumeGlanceMetadata object for provided fields. First delete any existing metadata then save new values. """ LOG.debug("Restoring volume glance metadata") metadata = self._filter(metadata, fields) self.db.volume_glance_metadata_delete_by_volume(self.context, volume_id) for key, value in metadata.items(): self.db.volume_glance_metadata_create(self.context, volume_id, key, value) # Now mark the volume as bootable self.db.volume_update(self.context, volume_id, {'bootable': True}) def _v1_restore_factory(self): """All metadata is backed up but we selectively restore. Returns a dictionary of the form: {: (, )} Empty field list indicates that all backed up fields should be restored. """ return {self.TYPE_TAG_VOL_META: (self._restore_vol_meta, []), self.TYPE_TAG_VOL_GLANCE_META: (self._restore_vol_glance_meta, [])} def _v2_restore_factory(self): """All metadata is backed up but we selectively restore. Returns a dictionary of the form: {: (, )} Empty field list indicates that all backed up fields should be restored. """ return {self.TYPE_TAG_VOL_BASE_META: (self._restore_vol_base_meta, ['encryption_key_id']), self.TYPE_TAG_VOL_META: (self._restore_vol_meta, []), self.TYPE_TAG_VOL_GLANCE_META: (self._restore_vol_glance_meta, [])} def get(self, volume_id): """Get volume metadata. Returns a json-encoded dict containing all metadata and the restore version i.e. the version used to decide what actually gets restored from this container when doing a backup restore. """ container = {'version': CONF.backup_metadata_version} self._save_vol_base_meta(container, volume_id) self._save_vol_meta(container, volume_id) self._save_vol_glance_meta(container, volume_id) if container: return jsonutils.dumps(container) else: return None def put(self, volume_id, json_metadata): """Restore volume metadata to a volume. The json container should contain a version that is supported here. """ meta_container = jsonutils.loads(json_metadata) version = meta_container['version'] if version == 1: factory = self._v1_restore_factory() elif version == 2: factory = self._v2_restore_factory() else: msg = (_("Unsupported backup metadata version (%s)") % (version)) raise exception.BackupMetadataUnsupportedVersion(msg) for type in factory: func = factory[type][0] fields = factory[type][1] if type in meta_container: func(meta_container[type], volume_id, fields) else: LOG.debug("No metadata of type '%s' to restore", type) @six.add_metaclass(abc.ABCMeta) class BackupDriver(base.Base): def __init__(self, context, db_driver=None): super(BackupDriver, self).__init__(db_driver) self.context = context self.backup_meta_api = BackupMetadataAPI(context, db_driver) # This flag indicates if backup driver supports force # deletion. So it should be set to True if the driver that inherits # from BackupDriver supports the force deletion function. self.support_force_delete = False def get_metadata(self, volume_id): return self.backup_meta_api.get(volume_id) def put_metadata(self, volume_id, json_metadata): self.backup_meta_api.put(volume_id, json_metadata) @abc.abstractmethod def backup(self, backup, volume_file, backup_metadata=False): """Start a backup of a specified volume.""" return @abc.abstractmethod def restore(self, backup, volume_id, volume_file): """Restore a saved backup.""" return @abc.abstractmethod def delete(self, backup): """Delete a saved backup.""" return def export_record(self, backup): """Export driver specific backup record information. If backup backend needs additional driver specific information to import backup record back into the system it must overwrite this method and return it here as a dictionary so it can be serialized into a string. Default backup driver implementation has no extra information. :param backup: backup object to export :returns driver_info - dictionary with extra information """ return {} def import_record(self, backup, driver_info): """Import driver specific backup record information. If backup backend needs additional driver specific information to import backup record back into the system it must overwrite this method since it will be called with the extra information that was provided by export_record when exporting the backup. Default backup driver implementation does nothing since it didn't export any specific data in export_record. :param backup: backup object to export :param driver_info: dictionary with driver specific backup record information :returns nothing """ return @six.add_metaclass(abc.ABCMeta) class BackupDriverWithVerify(BackupDriver): @abc.abstractmethod def verify(self, backup): """Verify that the backup exists on the backend. Verify that the backup is OK, possibly following an import record operation. :param backup: backup id of the backup to verify :raises: InvalidBackup, NotImplementedError """ return