134 lines
5.7 KiB
Python
134 lines
5.7 KiB
Python
# 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 oslo.config import cfg
|
|
from sqlalchemy import sql
|
|
|
|
from neutron.common import constants
|
|
from neutron.db import agents_db
|
|
from neutron.db import agentschedulers_db
|
|
from neutron.openstack.common.db import exception as db_exc
|
|
from neutron.openstack.common import log as logging
|
|
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
class ChanceScheduler(object):
|
|
"""Allocate a DHCP agent for a network in a random way.
|
|
More sophisticated scheduler (similar to filter scheduler in nova?)
|
|
can be introduced later.
|
|
"""
|
|
|
|
def _schedule_bind_network(self, context, agents, network_id):
|
|
for agent in agents:
|
|
context.session.begin(subtransactions=True)
|
|
try:
|
|
binding = agentschedulers_db.NetworkDhcpAgentBinding()
|
|
binding.dhcp_agent = agent
|
|
binding.network_id = network_id
|
|
context.session.add(binding)
|
|
# try to actually write the changes and catch integrity
|
|
# DBDuplicateEntry
|
|
context.session.commit()
|
|
except db_exc.DBDuplicateEntry:
|
|
# it's totally ok, someone just did our job!
|
|
context.session.rollback()
|
|
LOG.info(_('Agent %s already present'), agent)
|
|
LOG.debug(_('Network %(network_id)s is scheduled to be '
|
|
'hosted by DHCP agent %(agent_id)s'),
|
|
{'network_id': network_id,
|
|
'agent_id': agent})
|
|
|
|
def schedule(self, plugin, context, network):
|
|
"""Schedule the network to active DHCP agent(s).
|
|
|
|
A list of scheduled agents is returned.
|
|
"""
|
|
agents_per_network = cfg.CONF.dhcp_agents_per_network
|
|
|
|
#TODO(gongysh) don't schedule the networks with only
|
|
# subnets whose enable_dhcp is false
|
|
with context.session.begin(subtransactions=True):
|
|
dhcp_agents = plugin.get_dhcp_agents_hosting_networks(
|
|
context, [network['id']], active=True)
|
|
if len(dhcp_agents) >= agents_per_network:
|
|
LOG.debug(_('Network %s is hosted already'),
|
|
network['id'])
|
|
return
|
|
n_agents = agents_per_network - len(dhcp_agents)
|
|
enabled_dhcp_agents = plugin.get_agents_db(
|
|
context, filters={
|
|
'agent_type': [constants.AGENT_TYPE_DHCP],
|
|
'admin_state_up': [True]})
|
|
if not enabled_dhcp_agents:
|
|
LOG.warn(_('No more DHCP agents'))
|
|
return
|
|
active_dhcp_agents = [
|
|
agent for agent in set(enabled_dhcp_agents)
|
|
if not agents_db.AgentDbMixin.is_agent_down(
|
|
agent['heartbeat_timestamp'])
|
|
and agent not in dhcp_agents
|
|
]
|
|
if not active_dhcp_agents:
|
|
LOG.warn(_('No more DHCP agents'))
|
|
return
|
|
n_agents = min(len(active_dhcp_agents), n_agents)
|
|
chosen_agents = random.sample(active_dhcp_agents, n_agents)
|
|
self._schedule_bind_network(context, chosen_agents, network['id'])
|
|
return chosen_agents
|
|
|
|
def auto_schedule_networks(self, plugin, context, host):
|
|
"""Schedule non-hosted networks to the DHCP agent on
|
|
the specified host.
|
|
"""
|
|
agents_per_network = cfg.CONF.dhcp_agents_per_network
|
|
# a list of (agent, net_ids) tuples
|
|
bindings_to_add = []
|
|
with context.session.begin(subtransactions=True):
|
|
fields = ['network_id', 'enable_dhcp']
|
|
subnets = plugin.get_subnets(context, fields=fields)
|
|
net_ids = set(s['network_id'] for s in subnets
|
|
if s['enable_dhcp'])
|
|
if not net_ids:
|
|
LOG.debug(_('No non-hosted networks'))
|
|
return False
|
|
query = context.session.query(agents_db.Agent)
|
|
query = query.filter(agents_db.Agent.agent_type ==
|
|
constants.AGENT_TYPE_DHCP,
|
|
agents_db.Agent.host == host,
|
|
agents_db.Agent.admin_state_up == sql.true())
|
|
dhcp_agents = query.all()
|
|
for dhcp_agent in dhcp_agents:
|
|
if agents_db.AgentDbMixin.is_agent_down(
|
|
dhcp_agent.heartbeat_timestamp):
|
|
LOG.warn(_('DHCP agent %s is not active'), dhcp_agent.id)
|
|
continue
|
|
for net_id in net_ids:
|
|
agents = plugin.get_dhcp_agents_hosting_networks(
|
|
context, [net_id], active=True)
|
|
if len(agents) >= agents_per_network:
|
|
continue
|
|
if any(dhcp_agent.id == agent.id for agent in agents):
|
|
continue
|
|
bindings_to_add.append((dhcp_agent, net_id))
|
|
# do it outside transaction so particular scheduling results don't
|
|
# make other to fail
|
|
for agent, net_id in bindings_to_add:
|
|
self._schedule_bind_network(context, [agent], net_id)
|
|
return True
|