nova-solver-scheduler/nova_solverscheduler/scheduler/solvers/constraints/aggregate_num_instances.py

53 lines
1.8 KiB
Python

# Copyright (c) 2015 Cisco Systems 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
from oslo_log import log as logging
from nova.i18n import _LW
from nova_solverscheduler.scheduler.solvers.constraints \
import num_instances_constraint
from nova_solverscheduler.scheduler.solvers import utils
CONF = cfg.CONF
CONF.import_opt('max_instances_per_host',
'nova.scheduler.filters.num_instances_filter')
LOG = logging.getLogger(__name__)
class AggregateNumInstancesConstraint(
num_instances_constraint.NumInstancesConstraint):
"""AggregateNumInstancesConstraint with per-aggregate max num instances
per host.
Fall back to global max_instances_per_host if no per-aggregate setting
found.
"""
def _get_max_instances_per_host(self, host_state, filter_properties):
aggregate_vals = utils.aggregate_values_from_key(
host_state, 'max_instances_per_host')
try:
value = utils.validate_num_values(
aggregate_vals, CONF.max_instances_per_host, cast_to=int)
except ValueError as e:
LOG.warning(_LW("Could not decode max_instances_per_host: '%s'"),
e)
value = CONF.max_instances_per_host
return value