122 lines
4.0 KiB
Python
122 lines
4.0 KiB
Python
# -*- coding: utf-8 -*-
|
|
#
|
|
# 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 etcd3
|
|
from etcd3 import exceptions as etcd3_exc
|
|
from oslo_utils import encodeutils
|
|
import six
|
|
|
|
from tooz import coordination
|
|
from tooz import locking
|
|
from tooz import utils
|
|
|
|
|
|
def _translate_failures(func):
|
|
"""Translates common requests exceptions into tooz exceptions."""
|
|
|
|
@six.wraps(func)
|
|
def wrapper(*args, **kwargs):
|
|
try:
|
|
return func(*args, **kwargs)
|
|
except etcd3_exc.ConnectionFailedError as e:
|
|
utils.raise_with_cause(coordination.ToozConnectionError,
|
|
encodeutils.exception_to_unicode(e),
|
|
cause=e)
|
|
except etcd3_exc.ConnectionTimeoutError as e:
|
|
utils.raise_with_cause(coordination.OperationTimedOut,
|
|
encodeutils.exception_to_unicode(e),
|
|
cause=e)
|
|
except etcd3_exc.Etcd3Exception as e:
|
|
utils.raise_with_cause(coordination.ToozError,
|
|
encodeutils.exception_to_unicode(e),
|
|
cause=e)
|
|
|
|
return wrapper
|
|
|
|
|
|
class Etcd3Lock(locking.Lock):
|
|
"""An etcd3-specific lock.
|
|
|
|
Thin wrapper over etcd3's lock object basically to provide the heartbeat()
|
|
semantics for the coordination driver.
|
|
"""
|
|
|
|
def __init__(self, etcd3_lock, coord):
|
|
super(Etcd3Lock, self).__init__(etcd3_lock.name)
|
|
self._lock = etcd3_lock
|
|
self._coord = coord
|
|
|
|
@_translate_failures
|
|
def acquire(self, *args, **kwargs):
|
|
res = self._lock.acquire()
|
|
if res:
|
|
self._coord._acquired_locks.add(self)
|
|
return res
|
|
|
|
@_translate_failures
|
|
def release(self, *args, **kwargs):
|
|
if self._lock.is_acquired():
|
|
res = self._lock.release()
|
|
if res:
|
|
self._coord._acquired_locks.remove(self)
|
|
|
|
@_translate_failures
|
|
def break_(self):
|
|
res = self._lock.release()
|
|
if res:
|
|
self._coord._acquired_locks.remove(self)
|
|
|
|
@_translate_failures
|
|
def heartbeat(self):
|
|
return self._lock.refresh()
|
|
|
|
|
|
class Etcd3Driver(coordination.CoordinationDriver):
|
|
"""An etcd based driver.
|
|
|
|
This driver uses etcd provide the coordination driver semantics and
|
|
required API(s).
|
|
"""
|
|
|
|
#: Default socket/lock/member/leader timeout used when none is provided.
|
|
DEFAULT_TIMEOUT = 30
|
|
|
|
#: Default hostname used when none is provided.
|
|
DEFAULT_HOST = "localhost"
|
|
|
|
#: Default port used if none provided (4001 or 2379 are the common ones).
|
|
DEFAULT_PORT = 2379
|
|
|
|
def __init__(self, member_id, parsed_url, options):
|
|
super(Etcd3Driver, self).__init__(member_id)
|
|
host = parsed_url.hostname or self.DEFAULT_HOST
|
|
port = parsed_url.port or self.DEFAULT_PORT
|
|
options = utils.collapse(options)
|
|
timeout = int(options.get('timeout', self.DEFAULT_TIMEOUT))
|
|
self.client = etcd3.client(host=host, port=port, timeout=timeout)
|
|
self.lock_timeout = int(options.get('lock_timeout', timeout))
|
|
self._acquired_locks = set()
|
|
|
|
def get_lock(self, name):
|
|
etcd3_lock = self.client.lock(name, ttl=self.lock_timeout)
|
|
return Etcd3Lock(etcd3_lock, self)
|
|
|
|
def heartbeat(self):
|
|
# NOTE(jaypipes): Copying because set can mutate during iteration
|
|
for lock in self._acquired_locks.copy():
|
|
lock.heartbeat()
|
|
return self.lock_timeout
|