/usr/lib/python2.7/dist-packages/neutron_lbaas/agent_scheduler.py is in python-neutron-lbaas 1:9.1.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 | # Copyright (c) 2013 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.
import random
from neutron.db import agents_db
from neutron.db import agentschedulers_db
from neutron.db import model_base
from oslo_log import log as logging
import six
import sqlalchemy as sa
from sqlalchemy import orm
from sqlalchemy.orm import joinedload
from neutron_lbaas._i18n import _LW
from neutron_lbaas.extensions import lbaas_agentschedulerv2
from neutron_lbaas.services.loadbalancer import constants as lb_const
LOG = logging.getLogger(__name__)
class LoadbalancerAgentBinding(model_base.BASEV2):
"""Represents binding between neutron loadbalancer and agents."""
__tablename__ = "lbaas_loadbalanceragentbindings"
loadbalancer_id = sa.Column(
sa.String(36),
sa.ForeignKey("lbaas_loadbalancers.id", ondelete='CASCADE'),
primary_key=True)
agent = orm.relation(agents_db.Agent)
agent_id = sa.Column(
sa.String(36),
sa.ForeignKey("agents.id", ondelete='CASCADE'),
nullable=False)
class LbaasAgentSchedulerDbMixin(agentschedulers_db.AgentSchedulerDbMixin,
lbaas_agentschedulerv2
.LbaasAgentSchedulerPluginBase):
agent_notifiers = {}
def get_agent_hosting_loadbalancer(self, context,
loadbalancer_id, active=None):
query = context.session.query(LoadbalancerAgentBinding)
query = query.options(joinedload('agent'))
binding = query.get(loadbalancer_id)
if (binding and self.is_eligible_agent(
active, binding.agent)):
return {'agent': self._make_agent_dict(binding.agent)}
def get_lbaas_agents(self, context, active=None, filters=None):
query = context.session.query(agents_db.Agent)
query = query.filter_by(agent_type=lb_const.AGENT_TYPE_LOADBALANCERV2)
if active is not None:
query = query.filter_by(admin_state_up=active)
if filters:
for key, value in six.iteritems(filters):
column = getattr(agents_db.Agent, key, None)
if column:
query = query.filter(column.in_(value))
return [agent
for agent in query
if self.is_eligible_agent(active, agent)]
def list_loadbalancers_on_lbaas_agent(self, context, id):
query = context.session.query(
LoadbalancerAgentBinding.loadbalancer_id)
query = query.filter_by(agent_id=id)
loadbalancer_ids = [item[0] for item in query]
if loadbalancer_ids:
lbs = self.get_loadbalancers(context,
filters={'id': loadbalancer_ids})
return lbs
return []
def get_lbaas_agent_candidates(self, device_driver, active_agents):
candidates = []
for agent in active_agents:
agent_conf = self.get_configuration_dict(agent)
if device_driver in agent_conf['device_drivers']:
candidates.append(agent)
return candidates
class ChanceScheduler(object):
"""Allocate a loadbalancer agent for a vip in a random way."""
def schedule(self, plugin, context, loadbalancer, device_driver):
"""Schedule the load balancer to an active loadbalancer agent if there
is no enabled agent hosting it.
"""
with context.session.begin(subtransactions=True):
lbaas_agent = plugin.db.get_agent_hosting_loadbalancer(
context, loadbalancer.id)
if lbaas_agent:
LOG.debug('Load balancer %(loadbalancer_id)s '
'has already been hosted'
' by lbaas agent %(agent_id)s',
{'loadbalancer_id': loadbalancer.id,
'agent_id': lbaas_agent['id']})
return
active_agents = plugin.db.get_lbaas_agents(context, active=True)
if not active_agents:
LOG.warning(
_LW('No active lbaas agents for load balancer %s'),
loadbalancer.id)
return
candidates = plugin.db.get_lbaas_agent_candidates(device_driver,
active_agents)
if not candidates:
LOG.warning(_LW('No lbaas agent supporting device driver %s'),
device_driver)
return
chosen_agent = random.choice(candidates)
binding = LoadbalancerAgentBinding()
binding.agent = chosen_agent
binding.loadbalancer_id = loadbalancer.id
context.session.add(binding)
LOG.debug(
'Load balancer %(loadbalancer_id)s is scheduled '
'to lbaas agent %(agent_id)s', {
'loadbalancer_id': loadbalancer.id,
'agent_id': chosen_agent['id']}
)
return chosen_agent
|