senlin/senlin/policies/placement_policy.py

77 lines
2.1 KiB
Python

# 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.
"""
Policy for placing nodes across AZs and/or regions.
NOTE: How placement policy works
Input:
cluster: cluster whose nodes are to be manipulated.
action.data['placement']:
- count: number of nodes to create; it can be decision from a scaling
policy. If no scaling policy is in effect, the count will be
assumed to be 1.
Output:
stored in action.data: A dictionary containing scheduling decisions made.
{
'status': 'OK',
'placement': {
'count': 2,
'placements': [
{
'AZ': 'nova-1',
'region': 'RegionOne',
},
{
'AZ': 'nova-2',
'region': 'RegionTwo',
}
]
}
}
"""
from senlin.common import consts
from senlin.policies import base
class PlacementPolicy(base.Policy):
'''Policy for placing members of a cluster.
This policy is expected to be enforced before new member(s) added to an
existing cluster.
'''
VERSION = '1.0'
TARGET = [
('BEFORE', consts.CLUSTER_SCALE_OUT),
]
PROFILE_TYPE = [
'os.nova.server',
]
properties_schema = {
}
def __init__(self, name, spec, **kwargs):
super(PlacementPolicy, self).__init__(name, spec, **kwargs)
self.regions = self.properties.get('regions')
self.AZs = self.properties.get('availability_zones')
def pre_op(self, cluster_id, action):
'''Call back when new nodes are created for a cluster.'''
# TODO(anyone): calculate available AZs and or regions
return