vmware-nsx/neutron/services/loadbalancer/drivers/haproxy/namespace_driver.py
Oleg Bondarev 916d97b5d6 LBaaS: unify haproxy-on-host plugin driver and agent
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
2013-12-10 12:08:03 +04:00

353 lines
12 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright 2013 New Dream Network, LLC (DreamHost)
#
# 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.
#
# @author: Mark McClain, DreamHost
import os
import shutil
import socket
import netaddr
from oslo.config import cfg
from neutron.agent.common import config
from neutron.agent.linux import ip_lib
from neutron.agent.linux import utils
from neutron.common import exceptions
from neutron.openstack.common import importutils
from neutron.openstack.common import log as logging
from neutron.plugins.common import constants
from neutron.services.loadbalancer import constants as lb_const
from neutron.services.loadbalancer.drivers import agent_device_driver
from neutron.services.loadbalancer.drivers.haproxy import cfg as hacfg
LOG = logging.getLogger(__name__)
NS_PREFIX = 'qlbaas-'
DRIVER_NAME = 'haproxy_ns'
ACTIVE_PENDING = (
constants.ACTIVE,
constants.PENDING_CREATE,
constants.PENDING_UPDATE
)
STATE_PATH_DEFAULT = '$state_path/lbaas'
USER_GROUP_DEFAULT = 'nogroup'
OPTS = [
cfg.StrOpt(
'loadbalancer_state_path',
default=STATE_PATH_DEFAULT,
help=_('Location to store config and state files'),
deprecated_opts=[cfg.DeprecatedOpt('loadbalancer_state_path')],
),
cfg.StrOpt(
'user_group',
default=USER_GROUP_DEFAULT,
help=_('The user group'),
deprecated_opts=[cfg.DeprecatedOpt('user_group')],
)
]
cfg.CONF.register_opts(OPTS, 'haproxy')
class HaproxyNSDriver(agent_device_driver.AgentDeviceDriver):
def __init__(self, conf, plugin_rpc):
self.conf = conf
self.root_helper = config.get_root_helper(conf)
self.state_path = conf.haproxy.loadbalancer_state_path
try:
vif_driver = importutils.import_object(conf.interface_driver, conf)
except ImportError:
msg = (_('Error importing interface driver: %s')
% conf.haproxy.interface_driver)
LOG.error(msg)
raise
self.vif_driver = vif_driver
self.plugin_rpc = plugin_rpc
self.pool_to_port_id = {}
@classmethod
def get_name(cls):
return DRIVER_NAME
def create(self, logical_config):
pool_id = logical_config['pool']['id']
namespace = get_ns_name(pool_id)
self._plug(namespace, logical_config['vip']['port'])
self._spawn(logical_config)
def update(self, logical_config):
pool_id = logical_config['pool']['id']
pid_path = self._get_state_file_path(pool_id, 'pid')
extra_args = ['-sf']
extra_args.extend(p.strip() for p in open(pid_path, 'r'))
self._spawn(logical_config, extra_args)
def _spawn(self, logical_config, extra_cmd_args=()):
pool_id = logical_config['pool']['id']
namespace = get_ns_name(pool_id)
conf_path = self._get_state_file_path(pool_id, 'conf')
pid_path = self._get_state_file_path(pool_id, 'pid')
sock_path = self._get_state_file_path(pool_id, 'sock')
user_group = self.conf.haproxy.user_group
hacfg.save_config(conf_path, logical_config, sock_path, user_group)
cmd = ['haproxy', '-f', conf_path, '-p', pid_path]
cmd.extend(extra_cmd_args)
ns = ip_lib.IPWrapper(self.root_helper, namespace)
ns.netns.execute(cmd)
# remember the pool<>port mapping
self.pool_to_port_id[pool_id] = logical_config['vip']['port']['id']
def undeploy_instance(self, pool_id):
namespace = get_ns_name(pool_id)
ns = ip_lib.IPWrapper(self.root_helper, namespace)
pid_path = self._get_state_file_path(pool_id, 'pid')
# kill the process
kill_pids_in_file(self.root_helper, pid_path)
# unplug the ports
if pool_id in self.pool_to_port_id:
self._unplug(namespace, self.pool_to_port_id[pool_id])
# remove the configuration directory
conf_dir = os.path.dirname(self._get_state_file_path(pool_id, ''))
if os.path.isdir(conf_dir):
shutil.rmtree(conf_dir)
ns.garbage_collect_namespace()
def exists(self, pool_id):
namespace = get_ns_name(pool_id)
root_ns = ip_lib.IPWrapper(self.root_helper)
socket_path = self._get_state_file_path(pool_id, 'sock')
if root_ns.netns.exists(namespace) and os.path.exists(socket_path):
try:
s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
s.connect(socket_path)
return True
except socket.error:
pass
return False
def get_stats(self, pool_id):
socket_path = self._get_state_file_path(pool_id, 'sock')
TYPE_BACKEND_REQUEST = 2
TYPE_SERVER_REQUEST = 4
if os.path.exists(socket_path):
parsed_stats = self._get_stats_from_socket(
socket_path,
entity_type=TYPE_BACKEND_REQUEST | TYPE_SERVER_REQUEST)
pool_stats = self._get_backend_stats(parsed_stats)
pool_stats['members'] = self._get_servers_stats(parsed_stats)
return pool_stats
else:
LOG.warn(_('Stats socket not found for pool %s'), pool_id)
return {}
def _get_backend_stats(self, parsed_stats):
TYPE_BACKEND_RESPONSE = '1'
for stats in parsed_stats:
if stats.get('type') == TYPE_BACKEND_RESPONSE:
unified_stats = dict((k, stats.get(v, ''))
for k, v in hacfg.STATS_MAP.items())
return unified_stats
return {}
def _get_servers_stats(self, parsed_stats):
TYPE_SERVER_RESPONSE = '2'
res = {}
for stats in parsed_stats:
if stats.get('type') == TYPE_SERVER_RESPONSE:
res[stats['svname']] = {
lb_const.STATS_STATUS: (constants.INACTIVE
if stats['status'] == 'DOWN'
else constants.ACTIVE),
lb_const.STATS_HEALTH: stats['check_status'],
lb_const.STATS_FAILED_CHECKS: stats['chkfail']
}
return res
def _get_stats_from_socket(self, socket_path, entity_type):
try:
s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
s.connect(socket_path)
s.send('show stat -1 %s -1\n' % entity_type)
raw_stats = ''
chunk_size = 1024
while True:
chunk = s.recv(chunk_size)
raw_stats += chunk
if len(chunk) < chunk_size:
break
return self._parse_stats(raw_stats)
except socket.error as e:
LOG.warn(_('Error while connecting to stats socket: %s'), e)
return {}
def _parse_stats(self, raw_stats):
stat_lines = raw_stats.splitlines()
if len(stat_lines) < 2:
return []
stat_names = [name.strip('# ') for name in stat_lines[0].split(',')]
res_stats = []
for raw_values in stat_lines[1:]:
if not raw_values:
continue
stat_values = [value.strip() for value in raw_values.split(',')]
res_stats.append(dict(zip(stat_names, stat_values)))
return res_stats
def _get_state_file_path(self, pool_id, kind, ensure_state_dir=True):
"""Returns the file name for a given kind of config file."""
confs_dir = os.path.abspath(os.path.normpath(self.state_path))
conf_dir = os.path.join(confs_dir, pool_id)
if ensure_state_dir:
if not os.path.isdir(conf_dir):
os.makedirs(conf_dir, 0o755)
return os.path.join(conf_dir, kind)
def _plug(self, namespace, port, reuse_existing=True):
self.plugin_rpc.plug_vip_port(port['id'])
interface_name = self.vif_driver.get_device_name(Wrap(port))
if ip_lib.device_exists(interface_name, self.root_helper, namespace):
if not reuse_existing:
raise exceptions.PreexistingDeviceFailure(
dev_name=interface_name
)
else:
self.vif_driver.plug(
port['network_id'],
port['id'],
interface_name,
port['mac_address'],
namespace=namespace
)
cidrs = [
'%s/%s' % (ip['ip_address'],
netaddr.IPNetwork(ip['subnet']['cidr']).prefixlen)
for ip in port['fixed_ips']
]
self.vif_driver.init_l3(interface_name, cidrs, namespace=namespace)
gw_ip = port['fixed_ips'][0]['subnet'].get('gateway_ip')
if gw_ip:
cmd = ['route', 'add', 'default', 'gw', gw_ip]
ip_wrapper = ip_lib.IPWrapper(self.root_helper,
namespace=namespace)
ip_wrapper.netns.execute(cmd, check_exit_code=False)
def _unplug(self, namespace, port_id):
port_stub = {'id': port_id}
self.plugin_rpc.unplug_vip_port(port_id)
interface_name = self.vif_driver.get_device_name(Wrap(port_stub))
self.vif_driver.unplug(interface_name, namespace=namespace)
def deploy_instance(self, logical_config):
# do actual deploy only if vip is configured and active
if ('vip' not in logical_config or
logical_config['vip']['status'] not in ACTIVE_PENDING or
not logical_config['vip']['admin_state_up']):
return
if self.exists(logical_config['pool']['id']):
self.update(logical_config)
else:
self.create(logical_config)
def _refresh_device(self, pool_id):
logical_config = self.plugin_rpc.get_logical_device(pool_id)
self.deploy_instance(logical_config)
def create_vip(self, vip):
self._refresh_device(vip['pool_id'])
def update_vip(self, old_vip, vip):
self._refresh_device(vip['pool_id'])
def delete_vip(self, vip):
self.undeploy_instance(vip['pool_id'])
def create_pool(self, pool):
# nothing to do here because a pool needs a vip to be useful
pass
def update_pool(self, old_pool, pool):
self._refresh_device(pool['id'])
def delete_pool(self, pool):
# delete_pool may be called before vip deletion in case
# pool's admin state set to down
if self.exists(pool['id']):
self.undeploy_instance(pool['id'])
def create_member(self, member):
self._refresh_device(member['pool_id'])
def update_member(self, old_member, member):
self._refresh_device(member['pool_id'])
def delete_member(self, member):
self._refresh_device(member['pool_id'])
def create_pool_health_monitor(self, health_monitor, pool_id):
self._refresh_device(pool_id)
def update_pool_health_monitor(self, old_health_monitor, health_monitor,
pool_id):
self._refresh_device(pool_id)
def delete_pool_health_monitor(self, health_monitor, pool_id):
self._refresh_device(pool_id)
# NOTE (markmcclain) For compliance with interface.py which expects objects
class Wrap(object):
"""A light attribute wrapper for compatibility with the interface lib."""
def __init__(self, d):
self.__dict__.update(d)
def __getitem__(self, key):
return self.__dict__[key]
def get_ns_name(namespace_id):
return NS_PREFIX + namespace_id
def kill_pids_in_file(root_helper, pid_path):
if os.path.exists(pid_path):
with open(pid_path, 'r') as pids:
for pid in pids:
pid = pid.strip()
try:
utils.execute(['kill', '-9', pid], root_helper)
except RuntimeError:
LOG.exception(
_('Unable to kill haproxy process: %s'),
pid
)