b72c034885
OS-Brick uses file locks to ensure single access to critital sections, and uses the oslo concurrency "lock_path" configuration option to determine where to create these locks. This is fine when each host has a single service using os-brick, which is the case of Compute nodes and Controller nodes where Glance is not using Cinder as its backend. The problem happens when we have an HCI deployment where Cinder and Nova are collocated on the same host or when Glance uses Cinder as its backend and is running on the same host. In those scenarios os-brick will create file locks in different paths for each service, which is not the intended behavior. A possible solutions is to set the "lock_path" of all the services to the same location, which is not great, not only because we'll have all nova, cinder, glance, and os-brick locks mixed in a single location (service prefixes help a bit here), but also because then Cinder will have permissions on the Nova and Glance locks, which doesn't seem right. This patch introduces a new mechanism in os-brick to have its own "lock_path" configuration option in the "os_brick" group. It defaults to the current behavior if not explicitly defined, so it will use olso concurrency's "lock_path". To do this the patch introduces the oslo.config dependency and adds a new "setup" method that sets the default of the os_brick "lock_path". This new "setup" method is required because the order in which configuration options for the different namespaces are imported cannot be guaranteed, so the setup must be called *after* the service has already imported all (or at least the ones os-brick cares about) configuration option namespaces. In other words, when os-brick files are loaded the value for oslo concurrency's "lock_path" is not yet known, so it cannot be used as a default, and the oslo_config substitution feature does not support values from other namespaces, so we cannot default the "lock_path" from the os_brick namespace to the value in "oslo_concurrency". Since the value that is going to be used as the "lock_path" is not known until the "setup" method is called, we cannot use the standard "synchronized" method from "oslo_concurrency.lock_utils" and we need to use our own. In the current os-brick code, each connector that requires a lock is importing and creating its own "synchronized" instance, but this patch changes this behavior and creates a single instance, just like Cinder does. This feature requires changes in multiple projects -os-brick, cinder, nova, glance, glance_store, devstack- to be fully supported, but this is the base of all this effort. Change-Id: Ic52338278eb5bb3d90ce582fe6b23f37eb5568c4
46 lines
1.7 KiB
Python
46 lines
1.7 KiB
Python
# Copyright (c) 2022, 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 oslo_config import cfg
|
|
|
|
|
|
_opts = [
|
|
cfg.StrOpt('lock_path',
|
|
default=None, # Set by set_defaults method below on setup
|
|
help='Directory to use for os-brick lock files. Defaults to '
|
|
'oslo_concurrency.lock_path which is a sensible default '
|
|
'for compute nodes, but not for HCI deployments or '
|
|
'controllers where Glance uses Cinder as a backend, as '
|
|
'locks should use the same directory.'),
|
|
]
|
|
|
|
cfg.CONF.register_opts(_opts, group='os_brick')
|
|
|
|
|
|
def list_opts():
|
|
"""oslo.config.opts entrypoint for sample config generation."""
|
|
return [('os_brick', _opts)]
|
|
|
|
|
|
def set_defaults(conf=cfg.CONF):
|
|
"""Set default values that depend on other libraries.
|
|
|
|
Service configuration options must have been initialized before this call
|
|
because oslo's lock_path doesn't have a value before that.
|
|
|
|
Called from both os_brick setup and from the oslo.config.opts entrypoint
|
|
for sample config generation.
|
|
"""
|
|
conf.set_default('lock_path', conf.oslo_concurrency.lock_path, 'os_brick')
|