133 lines
5.6 KiB
Python
133 lines
5.6 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright (c) 2013 OpenStack Foundation.
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import random
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from oslo.config import cfg
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from sqlalchemy import sql
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from neutron.common import constants
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from neutron.db import agents_db
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from neutron.db import agentschedulers_db
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from neutron.openstack.common.db import exception as db_exc
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from neutron.openstack.common import log as logging
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LOG = logging.getLogger(__name__)
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class ChanceScheduler(object):
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"""Allocate a DHCP agent for a network in a random way.
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More sophisticated scheduler (similar to filter scheduler in nova?)
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can be introduced later.
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"""
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def _schedule_bind_network(self, context, agents, network_id):
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for agent in agents:
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context.session.begin(subtransactions=True)
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try:
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binding = agentschedulers_db.NetworkDhcpAgentBinding()
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binding.dhcp_agent = agent
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binding.network_id = network_id
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context.session.add(binding)
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# try to actually write the changes and catch integrity
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# DBDuplicateEntry
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context.session.commit()
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except db_exc.DBDuplicateEntry:
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# it's totally ok, someone just did our job!
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context.session.rollback()
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LOG.info(_('Agent %s already present'), agent)
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LOG.debug(_('Network %(network_id)s is scheduled to be '
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'hosted by DHCP agent %(agent_id)s'),
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{'network_id': network_id,
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'agent_id': agent})
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def schedule(self, plugin, context, network):
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"""Schedule the network to active DHCP agent(s).
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A list of scheduled agents is returned.
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"""
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agents_per_network = cfg.CONF.dhcp_agents_per_network
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#TODO(gongysh) don't schedule the networks with only
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# subnets whose enable_dhcp is false
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with context.session.begin(subtransactions=True):
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dhcp_agents = plugin.get_dhcp_agents_hosting_networks(
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context, [network['id']], active=True)
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if len(dhcp_agents) >= agents_per_network:
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LOG.debug(_('Network %s is hosted already'),
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network['id'])
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return
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n_agents = agents_per_network - len(dhcp_agents)
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enabled_dhcp_agents = plugin.get_agents_db(
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context, filters={
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'agent_type': [constants.AGENT_TYPE_DHCP],
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'admin_state_up': [True]})
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if not enabled_dhcp_agents:
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LOG.warn(_('No more DHCP agents'))
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return
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active_dhcp_agents = [
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agent for agent in set(enabled_dhcp_agents)
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if not agents_db.AgentDbMixin.is_agent_down(
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agent['heartbeat_timestamp'])
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and agent not in dhcp_agents
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]
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if not active_dhcp_agents:
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LOG.warn(_('No more DHCP agents'))
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return
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n_agents = min(len(active_dhcp_agents), n_agents)
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chosen_agents = random.sample(active_dhcp_agents, n_agents)
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self._schedule_bind_network(context, chosen_agents, network['id'])
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return chosen_agents
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def auto_schedule_networks(self, plugin, context, host):
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"""Schedule non-hosted networks to the DHCP agent on
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the specified host.
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"""
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agents_per_network = cfg.CONF.dhcp_agents_per_network
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with context.session.begin(subtransactions=True):
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query = context.session.query(agents_db.Agent)
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query = query.filter(agents_db.Agent.agent_type ==
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constants.AGENT_TYPE_DHCP,
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agents_db.Agent.host == host,
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agents_db.Agent.admin_state_up == sql.true())
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dhcp_agents = query.all()
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for dhcp_agent in dhcp_agents:
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if agents_db.AgentDbMixin.is_agent_down(
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dhcp_agent.heartbeat_timestamp):
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LOG.warn(_('DHCP agent %s is not active'), dhcp_agent.id)
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continue
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fields = ['network_id', 'enable_dhcp']
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subnets = plugin.get_subnets(context, fields=fields)
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net_ids = set(s['network_id'] for s in subnets
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if s['enable_dhcp'])
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if not net_ids:
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LOG.debug(_('No non-hosted networks'))
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return False
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for net_id in net_ids:
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agents = plugin.get_dhcp_agents_hosting_networks(
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context, [net_id], active=True)
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if len(agents) >= agents_per_network:
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continue
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if any(dhcp_agent.id == agent.id for agent in agents):
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continue
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binding = agentschedulers_db.NetworkDhcpAgentBinding()
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binding.dhcp_agent = dhcp_agent
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binding.network_id = net_id
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context.session.add(binding)
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return True
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