nova/nova/scheduler/filters/availability_zone_filter.py
Dan Smith f7c688b8ef Refined fix for validating image on rebuild
This aims to fix the issue described in bug 1664931 where a rebuild
fails to validate the existing host with the scheduler when a new
image is provided. The previous attempt to do this could cause rebuilds
to fail unnecessarily because we ran _all_ of the filters during a
rebuild, which could cause usage/resource filters to prevent an otherwise
valid rebuild from succeeding.

This aims to classify filters as useful for rebuild or not, and only apply
the former during a rebuild scheduler check. We do this by using an internal
scheduler hint, indicating our intent. This should (a) filter out
all hosts other than the one we're running on and (b) be detectable by
the filtering infrastructure as an internally-generated scheduling request
in order to trigger the correct filtering behavior.

Closes-Bug: #1664931
Change-Id: I1a46ef1503be2febcd20f4594f44344d05525446
2017-11-27 15:52:45 -05:00

64 lines
2.1 KiB
Python

# Copyright (c) 2011-2012 OpenStack Foundation
# 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_log import log as logging
import nova.conf
from nova.scheduler import filters
from nova.scheduler.filters import utils
LOG = logging.getLogger(__name__)
CONF = nova.conf.CONF
class AvailabilityZoneFilter(filters.BaseHostFilter):
"""Filters Hosts by availability zone.
Works with aggregate metadata availability zones, using the key
'availability_zone'
Note: in theory a compute node can be part of multiple availability_zones
"""
# Availability zones do not change within a request
run_filter_once_per_request = True
RUN_ON_REBUILD = False
def host_passes(self, host_state, spec_obj):
availability_zone = spec_obj.availability_zone
if not availability_zone:
return True
metadata = utils.aggregate_metadata_get_by_host(
host_state, key='availability_zone')
if 'availability_zone' in metadata:
hosts_passes = availability_zone in metadata['availability_zone']
host_az = metadata['availability_zone']
else:
hosts_passes = availability_zone == CONF.default_availability_zone
host_az = CONF.default_availability_zone
if not hosts_passes:
LOG.debug("Availability Zone '%(az)s' requested. "
"%(host_state)s has AZs: %(host_az)s",
{'host_state': host_state,
'az': availability_zone,
'host_az': host_az})
return hosts_passes