cinderlib/cinderlib/persistence/base.py
Hervé Beraud a6ce0fb43e Stop to use the __future__ module.
The __future__ module [1] was used in this context to ensure compatibility
between python 2 and python 3.

We previously dropped the support of python 2.7 [2] and now we only support
python 3 so we don't need to continue to use this module and the imports
listed below.

Imports commonly used and their related PEPs:
- `division` is related to PEP 238 [3]
- `print_function` is related to PEP 3105 [4]
- `unicode_literals` is related to PEP 3112 [5]
- `with_statement` is related to PEP 343 [6]
- `absolute_import` is related to PEP 328 [7]

[1] https://docs.python.org/3/library/__future__.html
[2] https://governance.openstack.org/tc/goals/selected/ussuri/drop-py27.html
[3] https://www.python.org/dev/peps/pep-0238
[4] https://www.python.org/dev/peps/pep-3105
[5] https://www.python.org/dev/peps/pep-3112
[6] https://www.python.org/dev/peps/pep-0343
[7] https://www.python.org/dev/peps/pep-0328

Change-Id: I9276da4050746a267b695102ce02c3cb85952a87
2020-06-02 20:08:16 +02:00

261 lines
9.7 KiB
Python

# Copyright (c) 2018, Red Hat, Inc.
# 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.
# NOTE(geguileo): Probably a good idea not to depend on cinder.cmd.volume
# having all the other imports as they could change.
from cinder import objects
from cinder.objects import base as cinder_base_ovo
from oslo_utils import timeutils
from oslo_versionedobjects import fields
import six
import cinderlib
from cinderlib import serialization
class PersistenceDriverBase(object):
"""Provide Metadata Persistency for our resources.
This class will be used to store new resources as they are created,
updated, and removed, as well as provide a mechanism for users to retrieve
volumes, snapshots, and connections.
"""
def __init__(self, **kwargs):
pass
@property
def db(self):
raise NotImplementedError()
def get_volumes(self, volume_id=None, volume_name=None, backend_name=None):
raise NotImplementedError()
def get_snapshots(self, snapshot_id=None, snapshot_name=None,
volume_id=None):
raise NotImplementedError()
def get_connections(self, connection_id=None, volume_id=None):
raise NotImplementedError()
def get_key_values(self, key):
raise NotImplementedError()
def set_volume(self, volume):
self.reset_change_tracker(volume)
if volume.volume_type:
volume.volume_type.obj_reset_changes()
if volume.volume_type.qos_specs_id:
volume.volume_type.qos_specs.obj_reset_changes()
def set_snapshot(self, snapshot):
self.reset_change_tracker(snapshot)
def set_connection(self, connection):
self.reset_change_tracker(connection)
def set_key_value(self, key_value):
pass
def delete_volume(self, volume):
self._set_deleted(volume)
self.reset_change_tracker(volume)
def delete_snapshot(self, snapshot):
self._set_deleted(snapshot)
self.reset_change_tracker(snapshot)
def delete_connection(self, connection):
self._set_deleted(connection)
self.reset_change_tracker(connection)
def delete_key_value(self, key):
pass
def _set_deleted(self, resource):
resource._ovo.deleted = True
resource._ovo.deleted_at = timeutils.utcnow()
if hasattr(resource._ovo, 'status'):
resource._ovo.status = 'deleted'
def reset_change_tracker(self, resource, fields=None):
if isinstance(fields, six.string_types):
fields = (fields,)
resource._ovo.obj_reset_changes(fields)
def get_changed_fields(self, resource):
# NOTE(geguileo): We don't use cinder_obj_get_changes to prevent
# recursion to children OVO which we are not interested and may result
# in circular references.
result = {key: getattr(resource._ovo, key)
for key in resource._changed_fields
if not isinstance(resource.fields[key], fields.ObjectField)}
if getattr(resource._ovo, 'volume_type', None):
if ('qos_specs' in resource.volume_type._changed_fields and
resource.volume_type.qos_specs):
result['qos_specs'] = resource._ovo.volume_type.qos_specs.specs
if ('extra_specs' in resource.volume_type._changed_fields and
resource.volume_type.extra_specs):
result['extra_specs'] = resource._ovo.volume_type.extra_specs
return result
def get_fields(self, resource):
result = {
key: getattr(resource._ovo, key)
for key in resource.fields
if (resource._ovo.obj_attr_is_set(key) and
key not in getattr(resource, 'obj_extra_fields', []) and not
isinstance(resource.fields[key], fields.ObjectField))
}
if getattr(resource._ovo, 'volume_type_id', None):
result['extra_specs'] = resource._ovo.volume_type.extra_specs
if resource._ovo.volume_type.qos_specs_id:
result['qos_specs'] = resource._ovo.volume_type.qos_specs.specs
return result
class DB(object):
"""Replacement for DB access methods.
This will serve as replacement for methods used by:
- Drivers
- OVOs' get_by_id and save methods
- DB implementation
Data will be retrieved using the persistence driver we setup.
"""
GET_METHODS_PER_DB_MODEL = {
objects.Volume.model: 'volume_get',
objects.VolumeType.model: 'volume_type_get',
objects.Snapshot.model: 'snapshot_get',
objects.QualityOfServiceSpecs.model: 'qos_specs_get',
}
def __init__(self, persistence_driver):
self.persistence = persistence_driver
# Replace get_by_id OVO methods with something that will return
# expected data
objects.Volume.get_by_id = self.volume_get
objects.Snapshot.get_by_id = self.snapshot_get
objects.VolumeAttachmentList.get_all_by_volume_id = \
self.__connections_get
# Disable saving in OVOs
for ovo_name in cinder_base_ovo.CinderObjectRegistry.obj_classes():
ovo_cls = getattr(objects, ovo_name)
ovo_cls.save = lambda *args, **kwargs: None
def __connections_get(self, context, volume_id):
# Used by drivers to lazy load volume_attachment
connections = self.persistence.get_connections(volume_id=volume_id)
ovos = [conn._ovo for conn in connections]
result = objects.VolumeAttachmentList(objects=ovos)
return result
def __volume_get(self, volume_id, as_ovo=True):
in_memory = volume_id in cinderlib.Backend._volumes_inflight
if in_memory:
vol = cinderlib.Backend._volumes_inflight[volume_id]
else:
vol = self.persistence.get_volumes(volume_id)[0]
vol_result = vol._ovo if as_ovo else vol
return in_memory, vol_result
def volume_get(self, context, volume_id, *args, **kwargs):
return self.__volume_get(volume_id)[1]
def snapshot_get(self, context, snapshot_id, *args, **kwargs):
return self.persistence.get_snapshots(snapshot_id)[0]._ovo
def volume_type_get(self, context, id, inactive=False,
expected_fields=None):
if id in cinderlib.Backend._volumes_inflight:
vol = cinderlib.Backend._volumes_inflight[id]
else:
vol = self.persistence.get_volumes(id)[0]
if not vol._ovo.volume_type_id:
return None
return vol_type_to_dict(vol._ovo.volume_type)
# Our volume type name is the same as the id and the volume name
def _volume_type_get_by_name(self, context, name, session=None):
return self.volume_type_get(context, name)
def qos_specs_get(self, context, qos_specs_id, inactive=False):
if qos_specs_id in cinderlib.Backend._volumes_inflight:
vol = cinderlib.Backend._volumes_inflight[qos_specs_id]
else:
vol = self.persistence.get_volumes(qos_specs_id)[0]
if not vol._ovo.volume_type_id:
return None
return vol_type_to_dict(vol._ovo.volume_type)['qos_specs']
@classmethod
def image_volume_cache_get_by_volume_id(cls, context, volume_id):
return None
def get_by_id(self, context, model, id, *args, **kwargs):
method = getattr(self, self.GET_METHODS_PER_DB_MODEL[model])
return method(context, id)
def volume_get_all_by_host(self, context, host, filters=None):
backend_name = host.split('#')[0].split('@')[1]
result = self.persistence.get_volumes(backend_name=backend_name)
return [vol._ovo for vol in result]
def _volume_admin_metadata_get(self, context, volume_id, session=None):
vol = self.volume_get(context, volume_id)
return vol.admin_metadata
def _volume_admin_metadata_update(self, context, volume_id, metadata,
delete, session=None, add=True,
update=True):
vol_in_memory, vol = self.__volume_get(volume_id, as_ovo=False)
changed = False
if delete:
remove = set(vol.admin_metadata.keys()).difference(metadata.keys())
changed = bool(remove)
for k in remove:
del vol.admin_metadata[k]
for k, v in metadata.items():
is_in = k in vol.admin_metadata
if (not is_in and add) or (is_in and update):
vol.admin_metadata[k] = v
changed = True
if changed and not vol_in_memory:
vol._changed_fields.add('admin_metadata')
self.persistence.set_volume(vol)
def volume_admin_metadata_delete(self, context, volume_id, key):
vol_in_memory, vol = self.__volume_get(volume_id, as_ovo=False)
if key in vol.admin_metadata:
del vol.admin_metadata[key]
if not vol_in_memory:
vol._changed_fields.add('admin_metadata')
self.persistence.set_volume(vol)
def vol_type_to_dict(volume_type):
res = serialization.obj_to_primitive(volume_type)
res = res['versioned_object.data']
if res.get('qos_specs'):
res['qos_specs'] = res['qos_specs']['versioned_object.data']
return res