vmware-nsx/neutron/service.py
2014-12-14 02:58:34 +00:00

298 lines
10 KiB
Python

# Copyright 2011 VMware, Inc
# 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 inspect
import logging as std_logging
import os
import random
from oslo.config import cfg
from oslo.messaging import server as rpc_server
from oslo.utils import excutils
from oslo.utils import importutils
from neutron.common import config
from neutron.common import rpc as n_rpc
from neutron import context
from neutron.db import api as session
from neutron.i18n import _LE, _LI
from neutron import manager
from neutron.openstack.common import log as logging
from neutron.openstack.common import loopingcall
from neutron.openstack.common import service as common_service
from neutron import wsgi
service_opts = [
cfg.IntOpt('periodic_interval',
default=40,
help=_('Seconds between running periodic tasks')),
cfg.IntOpt('api_workers',
default=0,
help=_('Number of separate API worker processes for service')),
cfg.IntOpt('rpc_workers',
default=0,
help=_('Number of RPC worker processes for service')),
cfg.IntOpt('periodic_fuzzy_delay',
default=5,
help=_('Range of seconds to randomly delay when starting the '
'periodic task scheduler to reduce stampeding. '
'(Disable by setting to 0)')),
]
CONF = cfg.CONF
CONF.register_opts(service_opts)
LOG = logging.getLogger(__name__)
class WsgiService(object):
"""Base class for WSGI based services.
For each api you define, you must also define these flags:
:<api>_listen: The address on which to listen
:<api>_listen_port: The port on which to listen
"""
def __init__(self, app_name):
self.app_name = app_name
self.wsgi_app = None
def start(self):
self.wsgi_app = _run_wsgi(self.app_name)
def wait(self):
self.wsgi_app.wait()
class NeutronApiService(WsgiService):
"""Class for neutron-api service."""
@classmethod
def create(cls, app_name='neutron'):
# Setup logging early, supplying both the CLI options and the
# configuration mapping from the config file
# We only update the conf dict for the verbose and debug
# flags. Everything else must be set up in the conf file...
# Log the options used when starting if we're in debug mode...
config.setup_logging()
# Dump the initial option values
cfg.CONF.log_opt_values(LOG, std_logging.DEBUG)
service = cls(app_name)
return service
def serve_wsgi(cls):
try:
service = cls.create()
service.start()
except Exception:
with excutils.save_and_reraise_exception():
LOG.exception(_LE('Unrecoverable error: please check log '
'for details.'))
return service
class RpcWorker(object):
"""Wraps a worker to be handled by ProcessLauncher"""
def __init__(self, plugin):
self._plugin = plugin
self._servers = []
def start(self):
# We may have just forked from parent process. A quick disposal of the
# existing sql connections avoids producing errors later when they are
# discovered to be broken.
session.get_engine().pool.dispose()
self._servers = self._plugin.start_rpc_listeners()
def wait(self):
for server in self._servers:
if isinstance(server, rpc_server.MessageHandlingServer):
server.wait()
def stop(self):
for server in self._servers:
if isinstance(server, rpc_server.MessageHandlingServer):
server.stop()
self._servers = []
def serve_rpc():
plugin = manager.NeutronManager.get_plugin()
# If 0 < rpc_workers then start_rpc_listeners would be called in a
# subprocess and we cannot simply catch the NotImplementedError. It is
# simpler to check this up front by testing whether the plugin supports
# multiple RPC workers.
if not plugin.rpc_workers_supported():
LOG.debug("Active plugin doesn't implement start_rpc_listeners")
if 0 < cfg.CONF.rpc_workers:
LOG.error(_LE("'rpc_workers = %d' ignored because "
"start_rpc_listeners is not implemented."),
cfg.CONF.rpc_workers)
raise NotImplementedError()
try:
rpc = RpcWorker(plugin)
if cfg.CONF.rpc_workers < 1:
rpc.start()
return rpc
else:
launcher = common_service.ProcessLauncher(wait_interval=1.0)
launcher.launch_service(rpc, workers=cfg.CONF.rpc_workers)
return launcher
except Exception:
with excutils.save_and_reraise_exception():
LOG.exception(_LE('Unrecoverable error: please check log for '
'details.'))
def _run_wsgi(app_name):
app = config.load_paste_app(app_name)
if not app:
LOG.error(_LE('No known API applications configured.'))
return
server = wsgi.Server("Neutron")
server.start(app, cfg.CONF.bind_port, cfg.CONF.bind_host,
workers=cfg.CONF.api_workers)
# Dump all option values here after all options are parsed
cfg.CONF.log_opt_values(LOG, std_logging.DEBUG)
LOG.info(_LI("Neutron service started, listening on %(host)s:%(port)s"),
{'host': cfg.CONF.bind_host, 'port': cfg.CONF.bind_port})
return server
class Service(n_rpc.Service):
"""Service object for binaries running on hosts.
A service takes a manager and enables rpc by listening to queues based
on topic. It also periodically runs tasks on the manager.
"""
def __init__(self, host, binary, topic, manager, report_interval=None,
periodic_interval=None, periodic_fuzzy_delay=None,
*args, **kwargs):
self.binary = binary
self.manager_class_name = manager
manager_class = importutils.import_class(self.manager_class_name)
self.manager = manager_class(host=host, *args, **kwargs)
self.report_interval = report_interval
self.periodic_interval = periodic_interval
self.periodic_fuzzy_delay = periodic_fuzzy_delay
self.saved_args, self.saved_kwargs = args, kwargs
self.timers = []
super(Service, self).__init__(host, topic, manager=self.manager)
def start(self):
self.manager.init_host()
super(Service, self).start()
if self.report_interval:
pulse = loopingcall.FixedIntervalLoopingCall(self.report_state)
pulse.start(interval=self.report_interval,
initial_delay=self.report_interval)
self.timers.append(pulse)
if self.periodic_interval:
if self.periodic_fuzzy_delay:
initial_delay = random.randint(0, self.periodic_fuzzy_delay)
else:
initial_delay = None
periodic = loopingcall.FixedIntervalLoopingCall(
self.periodic_tasks)
periodic.start(interval=self.periodic_interval,
initial_delay=initial_delay)
self.timers.append(periodic)
self.manager.after_start()
def __getattr__(self, key):
manager = self.__dict__.get('manager', None)
return getattr(manager, key)
@classmethod
def create(cls, host=None, binary=None, topic=None, manager=None,
report_interval=None, periodic_interval=None,
periodic_fuzzy_delay=None):
"""Instantiates class and passes back application object.
:param host: defaults to CONF.host
:param binary: defaults to basename of executable
:param topic: defaults to bin_name - 'neutron-' part
:param manager: defaults to CONF.<topic>_manager
:param report_interval: defaults to CONF.report_interval
:param periodic_interval: defaults to CONF.periodic_interval
:param periodic_fuzzy_delay: defaults to CONF.periodic_fuzzy_delay
"""
if not host:
host = CONF.host
if not binary:
binary = os.path.basename(inspect.stack()[-1][1])
if not topic:
topic = binary.rpartition('neutron-')[2]
topic = topic.replace("-", "_")
if not manager:
manager = CONF.get('%s_manager' % topic, None)
if report_interval is None:
report_interval = CONF.report_interval
if periodic_interval is None:
periodic_interval = CONF.periodic_interval
if periodic_fuzzy_delay is None:
periodic_fuzzy_delay = CONF.periodic_fuzzy_delay
service_obj = cls(host, binary, topic, manager,
report_interval=report_interval,
periodic_interval=periodic_interval,
periodic_fuzzy_delay=periodic_fuzzy_delay)
return service_obj
def kill(self):
"""Destroy the service object."""
self.stop()
def stop(self):
super(Service, self).stop()
for x in self.timers:
try:
x.stop()
except Exception:
LOG.exception(_LE("Exception occurs when timer stops"))
self.timers = []
def wait(self):
super(Service, self).wait()
for x in self.timers:
try:
x.wait()
except Exception:
LOG.exception(_LE("Exception occurs when waiting for timer"))
def periodic_tasks(self, raise_on_error=False):
"""Tasks to be run at a periodic interval."""
ctxt = context.get_admin_context()
self.manager.periodic_tasks(ctxt, raise_on_error=raise_on_error)
def report_state(self):
"""Update the state of this service."""
# Todo(gongysh) report state to neutron server
pass