86 lines
2.9 KiB
Python
86 lines
2.9 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.
|
|
from __future__ import absolute_import
|
|
import inspect
|
|
|
|
from cinder.cmd import volume as volume_cmd
|
|
import six
|
|
from stevedore import driver
|
|
|
|
from cinderlib import exception
|
|
from cinderlib.persistence import base
|
|
|
|
|
|
DEFAULT_STORAGE = 'memory'
|
|
|
|
|
|
class MyDict(dict):
|
|
"""Custom non clearable dictionary.
|
|
|
|
Required to overcome the nature of oslo.config where configuration comes
|
|
from files and command line input.
|
|
|
|
Using this dictionary we can load from memory everything and it won't clear
|
|
things when we dynamically load a driver and the driver has new
|
|
configuration options.
|
|
"""
|
|
def clear(self):
|
|
pass
|
|
|
|
|
|
def setup(config):
|
|
"""Setup persistence to be used in cinderlib.
|
|
|
|
By default memory persistance will be used, but there are other mechanisms
|
|
available and other ways to use custom mechanisms:
|
|
|
|
- Persistence plugins: Plugin mechanism uses Python entrypoints under
|
|
namespace cinderlib.persistence.storage, and cinderlib comes with 3
|
|
different mechanisms, "memory", "dbms", and "memory_dbms". To use any of
|
|
these one must pass the string name in the storage parameter and any
|
|
other configuration as keyword arguments.
|
|
- Passing a class that inherits from PersistenceDriverBase as storage
|
|
parameter and initialization parameters as keyword arguments.
|
|
- Passing an instance that inherits from PersistenceDriverBase as storage
|
|
parameter.
|
|
"""
|
|
if config is None:
|
|
config = {}
|
|
else:
|
|
config = config.copy()
|
|
|
|
# Prevent driver dynamic loading clearing configuration options
|
|
volume_cmd.CONF._ConfigOpts__cache = MyDict()
|
|
|
|
# Default configuration is using memory storage
|
|
storage = config.pop('storage', None) or DEFAULT_STORAGE
|
|
if isinstance(storage, base.PersistenceDriverBase):
|
|
return storage
|
|
|
|
if inspect.isclass(storage) and issubclass(storage,
|
|
base.PersistenceDriverBase):
|
|
return storage(**config)
|
|
|
|
if not isinstance(storage, six.string_types):
|
|
raise exception.InvalidPersistence(storage)
|
|
|
|
persistence_driver = driver.DriverManager(
|
|
namespace='cinderlib.persistence.storage',
|
|
name=storage,
|
|
invoke_on_load=True,
|
|
invoke_kwds=config,
|
|
)
|
|
return persistence_driver.driver
|