deb-manila/manila/scheduler/drivers/chance.py
Clinton Knight af2e103514 Reorganize scheduler and merge code from Oslo incubator
With oslo-incubator going away, we need to pull those classes into
the Manila code base, along with their unit tests.  This presents a
good opportunity to do some long-needed housecleaning.  This commit
does the following:

1. Moves the scheduler classes from openstack.common to manila.
2. Adds the unit tests from olso-incubator into Manila.
3. Removes duplication among the combined scheduler modules.
4. Moves scheduler drivers into a sub-module.
5. Normalizes class and module naming throughout the scheduler.
6. Splits some unit test files so they match the names of the
   modules that they test.
7. Converts usage of mox & oslotest to mock & unittest.
8. Adds a few unit tests to boost coverage levels.

Implements: blueprint reorganize-manila-scheduler
Change-Id: I7aa237e17787e89a95bb198093ea9bc9498279cd
2015-12-01 20:54:17 +00:00

77 lines
2.6 KiB
Python

# Copyright (c) 2010 OpenStack, LLC.
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.
"""
Chance (Random) Scheduler implementation
"""
import random
from oslo_config import cfg
from manila import exception
from manila.i18n import _
from manila.scheduler.drivers import base
CONF = cfg.CONF
class ChanceScheduler(base.Scheduler):
"""Implements Scheduler as a random node selector."""
def _filter_hosts(self, request_spec, hosts, **kwargs):
"""Filter a list of hosts based on request_spec."""
filter_properties = kwargs.get('filter_properties', {})
ignore_hosts = filter_properties.get('ignore_hosts', [])
hosts = [host for host in hosts if host not in ignore_hosts]
return hosts
def _schedule(self, context, topic, request_spec, **kwargs):
"""Picks a host that is up at random."""
elevated = context.elevated()
hosts = self.hosts_up(elevated, topic)
if not hosts:
msg = _("Is the appropriate service running?")
raise exception.NoValidHost(reason=msg)
hosts = self._filter_hosts(request_spec, hosts, **kwargs)
if not hosts:
msg = _("Could not find another host")
raise exception.NoValidHost(reason=msg)
return hosts[int(random.random() * len(hosts))]
def schedule_create_share(self, context, request_spec, filter_properties):
"""Picks a host that is up at random."""
topic = CONF.share_topic
host = self._schedule(context, topic, request_spec,
filter_properties=filter_properties)
share_id = request_spec['share_id']
snapshot_id = request_spec['snapshot_id']
updated_share = base.share_update_db(context, share_id, host)
self.share_rpcapi.create_share_instance(
context,
updated_share.instance,
host,
request_spec,
filter_properties,
snapshot_id
)