916d97b5d6
Unifies haproxy reference implementation to make common agent based plugin driver which is suitable for all vendors who wants to use async mechanism. - Agent API as well as device driver API changed to handle loadbalancer objects individually; - Agent loads device drivers according to config; - LogicalDeviceCache class was removed from agent as it was used only as a list - to put and remove entries ant check whether entry is in or not. It was replaced with instance_mapping dict in agent to store known instances and corresponding device_drivers; - Agent reports which device drivers are supported (needs for scheduling on plugin side); - Agent-to-plugin API was extended to provide an ability for agent to update statuses of pools/vips/members/health_monitors; - Vendor should only implement device driver; plugin driver just needs to inherit AgentBasedPluginDriver and override device_driver member; - This patch doesn't move files to make review easier; all rename/replace will be done in a subsequent patch; DocImpact NOTE: Since the change in the agent RPC API is backward-incompatible (major RPC version change), LBaaS server-agent communications will be completely broken until both sides are upgraded so users will be unable to create new or update existing HAProxy loadbalancer instances during upgrade Implements blueprint lbaas-common-agent-driver Change-Id: I9fd90a1321611d202ef838681273081fa6c1686a
130 lines
5.1 KiB
Python
130 lines
5.1 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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import sqlalchemy as sa
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from sqlalchemy import orm
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from sqlalchemy.orm import joinedload
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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.db import model_base
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from neutron.extensions import lbaas_agentscheduler
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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 PoolLoadbalancerAgentBinding(model_base.BASEV2):
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"""Represents binding between neutron loadbalancer pools and agents."""
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pool_id = sa.Column(sa.String(36),
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sa.ForeignKey("pools.id", ondelete='CASCADE'),
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primary_key=True)
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agent = orm.relation(agents_db.Agent)
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agent_id = sa.Column(sa.String(36), sa.ForeignKey("agents.id",
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ondelete='CASCADE'))
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class LbaasAgentSchedulerDbMixin(agentschedulers_db.AgentSchedulerDbMixin,
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lbaas_agentscheduler
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.LbaasAgentSchedulerPluginBase):
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def get_lbaas_agent_hosting_pool(self, context, pool_id, active=None):
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query = context.session.query(PoolLoadbalancerAgentBinding)
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query = query.options(joinedload('agent'))
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binding = query.get(pool_id)
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if (binding and self.is_eligible_agent(
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active, binding.agent)):
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return {'agent': self._make_agent_dict(binding.agent)}
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def get_lbaas_agents(self, context, active=None, filters=None):
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query = context.session.query(agents_db.Agent)
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query = query.filter_by(agent_type=constants.AGENT_TYPE_LOADBALANCER)
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if active is not None:
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query = query.filter_by(admin_state_up=active)
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if filters:
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for key, value in filters.iteritems():
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column = getattr(agents_db.Agent, key, None)
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if column:
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query = query.filter(column.in_(value))
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return [agent
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for agent in query
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if self.is_eligible_agent(active, agent)]
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def list_pools_on_lbaas_agent(self, context, id):
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query = context.session.query(PoolLoadbalancerAgentBinding.pool_id)
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query = query.filter_by(agent_id=id)
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pool_ids = [item[0] for item in query]
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if pool_ids:
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return {'pools': self.get_pools(context, filters={'id': pool_ids})}
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else:
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return {'pools': []}
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def get_lbaas_agent_candidates(self, device_driver, active_agents):
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candidates = []
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for agent in active_agents:
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agent_conf = self.get_configuration_dict(agent)
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if device_driver in agent_conf['device_drivers']:
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candidates.append(agent)
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return candidates
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class ChanceScheduler(object):
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"""Allocate a loadbalancer agent for a vip in a random way."""
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def schedule(self, plugin, context, pool, device_driver):
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"""Schedule the pool to an active loadbalancer agent if there
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is no enabled agent hosting it.
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"""
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with context.session.begin(subtransactions=True):
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lbaas_agent = plugin.get_lbaas_agent_hosting_pool(
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context, pool['id'])
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if lbaas_agent:
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LOG.debug(_('Pool %(pool_id)s has already been hosted'
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' by lbaas agent %(agent_id)s'),
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{'pool_id': pool['id'],
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'agent_id': lbaas_agent['id']})
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return
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active_agents = plugin.get_lbaas_agents(context, active=True)
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if not active_agents:
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LOG.warn(_('No active lbaas agents for pool %s'), pool['id'])
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return
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candidates = plugin.get_lbaas_agent_candidates(device_driver,
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active_agents)
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if not candidates:
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LOG.warn(_('No lbaas agent supporting device driver %s'),
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device_driver)
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return
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chosen_agent = random.choice(candidates)
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binding = PoolLoadbalancerAgentBinding()
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binding.agent = chosen_agent
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binding.pool_id = pool['id']
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context.session.add(binding)
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LOG.debug(_('Pool %(pool_id)s is scheduled to '
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'lbaas agent %(agent_id)s'),
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{'pool_id': pool['id'],
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'agent_id': chosen_agent['id']})
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return chosen_agent
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