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# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# Copyright 2011 Justin Santa Barbara
# 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
# 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.
"""Generic Node base class for all workers that run on hosts."""
import os
import os.path
import random
import socket
import ssl
import sys
import eventlet
import eventlet.wsgi
import greenlet
from oslo_concurrency import processutils
from oslo_log import log as logging
import oslo_messaging as messaging
from oslo_service import service
from oslo_utils import excutils
from oslo_utils import importutils
from nova.api import wsgi as api_wsgi
from nova import baserpc
from nova import conductor
import nova.conf
from nova import context
from nova import debugger
from nova import exception
from nova.i18n import _
from nova import objects
from nova.objects import base as objects_base
from nova.objects import service as service_obj
from nova import rpc
from nova import servicegroup
from nova import utils
from nova import version
osprofiler = importutils.try_import("osprofiler")
osprofiler_initializer = importutils.try_import("osprofiler.initializer")
CONF = nova.conf.CONF
LOG = logging.getLogger(__name__)
'nova-compute': 'nova.compute.manager.ComputeManager',
'nova-conductor': 'nova.conductor.manager.ConductorManager',
'nova-scheduler': 'nova.scheduler.manager.SchedulerManager',
def _create_service_ref(this_service, context):
service = objects.Service(context) =
service.binary = this_service.binary
service.topic = this_service.topic
service.report_count = 0
return service
def _update_service_ref(service):
if service.version != service_obj.SERVICE_VERSION:'Updating service version for %(binary)s on '
'%(host)s from %(old)i to %(new)i',
{'binary': service.binary,
'old': service.version,
'new': service_obj.SERVICE_VERSION})
service.version = service_obj.SERVICE_VERSION
def setup_profiler(binary, host):
if osprofiler and CONF.profiler.enabled:
host=host)"OSProfiler is enabled.")
class Service(service.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 and reports
its state to the database services table.
def __init__(self, host, binary, topic, manager, report_interval=None,
periodic_enable=None, periodic_fuzzy_delay=None,
periodic_interval_max=None, *args, **kwargs):
super(Service, self).__init__() = host
self.binary = binary
self.topic = topic
self.manager_class_name = manager
self.servicegroup_api = servicegroup.API()
manager_class = importutils.import_class(self.manager_class_name)
if objects_base.NovaObject.indirection_api:
conductor_api = conductor.API()
self.manager = manager_class(, *args, **kwargs)
self.rpcserver = None
self.report_interval = report_interval
self.periodic_enable = periodic_enable
self.periodic_fuzzy_delay = periodic_fuzzy_delay
self.periodic_interval_max = periodic_interval_max
self.saved_args, self.saved_kwargs = args, kwargs
self.backdoor_port = None
def __repr__(self):
return "<%(cls_name)s: host=%(host)s, binary=%(binary)s, " \
"manager_class_name=%(manager)s>" % {
'cls_name': self.__class__.__name__,
'binary': self.binary,
'manager': self.manager_class_name
def start(self):
"""Start the service.
This includes starting an RPC service, initializing
periodic tasks, etc.
# NOTE(melwitt): Clear the cell cache holding database transaction
# context manager objects. We do this to ensure we create new internal
# oslo.db locks to avoid a situation where a child process receives an
# already locked oslo.db lock when it is forked. When a child process
# inherits a locked oslo.db lock, database accesses through that
# transaction context manager will never be able to acquire the lock
# and requests will fail with CellTimeout errors.
# See for more information.
# With python 3.7, it would be possible for oslo.db to make use of the
# os.register_at_fork() method to reinitialize its lock. Until we
# require python 3.7 as a minimum version, we must handle the situation
# outside of oslo.db.
context.CELL_CACHE = {}
verstr = version.version_string_with_package()'Starting %(topic)s node (version %(version)s)',
{'topic': self.topic, 'version': verstr})
ctxt = context.get_admin_context()
self.service_ref = objects.Service.get_by_host_and_binary(
ctxt,, self.binary)
self.model_disconnected = False
if self.service_ref:
self.service_ref = _create_service_ref(self, ctxt)
except (exception.ServiceTopicExists,
# NOTE(danms): If we race to create a record with a sibling
# worker, don't fail here.
self.service_ref = objects.Service.get_by_host_and_binary(
ctxt,, self.binary)
if self.backdoor_port is not None:
self.manager.backdoor_port = self.backdoor_port
LOG.debug("Creating RPC server for service %s", self.topic)
target = messaging.Target(topic=self.topic,
endpoints = [
baserpc.BaseRPCAPI(self.manager.service_name, self.backdoor_port)
serializer = objects_base.NovaObjectSerializer()
self.rpcserver = rpc.get_server(target, endpoints, serializer)
LOG.debug("Join ServiceGroup membership for this service %s",
# Add service to the ServiceGroup membership group.
self.servicegroup_api.join(, self.topic, self)
if self.periodic_enable:
if self.periodic_fuzzy_delay:
initial_delay = random.randint(0, self.periodic_fuzzy_delay)
initial_delay = None,
def __getattr__(self, key):
manager = self.__dict__.get('manager', None)
return getattr(manager, key)
def create(cls, host=None, binary=None, topic=None, manager=None,
report_interval=None, periodic_enable=None,
periodic_fuzzy_delay=None, periodic_interval_max=None):
"""Instantiates class and passes back application object.
:param host: defaults to
:param binary: defaults to basename of executable
:param topic: defaults to bin_name - 'nova-' part
:param manager: defaults to CONF.<topic>_manager
:param report_interval: defaults to CONF.report_interval
:param periodic_enable: defaults to CONF.periodic_enable
:param periodic_fuzzy_delay: defaults to CONF.periodic_fuzzy_delay
:param periodic_interval_max: if set, the max time to wait between runs
if not host:
host =
if not binary:
binary = os.path.basename(sys.argv[0])
if not topic:
topic = binary.rpartition('nova-')[2]
if not manager:
manager = SERVICE_MANAGERS.get(binary)
if report_interval is None:
report_interval = CONF.report_interval
if periodic_enable is None:
periodic_enable = CONF.periodic_enable
if periodic_fuzzy_delay is None:
periodic_fuzzy_delay = CONF.periodic_fuzzy_delay
service_obj = cls(host, binary, topic, manager,
# NOTE(gibi): This have to be after the service object creation as
# that is the point where we can safely use the RPC to the conductor.
# E.g. the Service.__init__ actually waits for the conductor to start
# up before it allows the service to be created. The
# raise_if_old_compute() depends on the RPC to be up and does not
# implement its own retry mechanism to connect to the conductor.
except exception.TooOldComputeService as e:
if CONF.workarounds.disable_compute_service_check_for_ffu:
return service_obj
def kill(self):
"""Destroy the service object in the datastore.
NOTE: Although this method is not used anywhere else than tests, it is
convenient to have it here, so the tests might easily and in clean way
stop and remove the service_ref.
except exception.NotFound:
LOG.warning('Service killed that has no database entry')
def stop(self):
"""stop the service and clean up."""
except Exception:
except Exception:
LOG.exception('Service error occurred during cleanup_host')
super(Service, self).stop()
def periodic_tasks(self, raise_on_error=False):
"""Tasks to be run at a periodic interval."""
ctxt = context.get_admin_context()
return self.manager.periodic_tasks(ctxt, raise_on_error=raise_on_error)
def basic_config_check(self):
"""Perform basic config checks before starting processing."""
# Make sure the tempdir exists and is writable
with utils.tempdir():
except Exception as e:
LOG.error('Temporary directory is invalid: %s', e)
def reset(self):
"""reset the service."""
# Reset the cell cache that holds database transaction context managers
context.CELL_CACHE = {}
class WSGIServer(service.ServiceBase):
"""Server class to manage a WSGI server, serving a WSGI application."""
default_pool_size = CONF.wsgi.default_pool_size
def __init__(self, name, app, host='', port=0, pool_size=None,
protocol=eventlet.wsgi.HttpProtocol, backlog=128,
use_ssl=False, max_url_len=None):
"""Initialize, but do not start, a WSGI server.
:param name: Pretty name for logging.
:param app: The WSGI application to serve.
:param host: IP address to serve the application.
:param port: Port number to server the application.
:param pool_size: Maximum number of eventlets to spawn concurrently.
:param backlog: Maximum number of queued connections.
:param max_url_len: Maximum length of permitted URLs.
:returns: None
:raises: nova.exception.InvalidInput
# Allow operators to customize http requests max header line size.
eventlet.wsgi.MAX_HEADER_LINE = CONF.wsgi.max_header_line = name = app
self._server = None
self._protocol = protocol
self.pool_size = pool_size or self.default_pool_size
self._pool = eventlet.GreenPool(self.pool_size)
self._logger = logging.getLogger("nova.%s.wsgi.server" %
self._use_ssl = use_ssl
self._max_url_len = max_url_len
self.client_socket_timeout = CONF.wsgi.client_socket_timeout or None
if backlog < 1:
raise exception.InvalidInput(
reason=_('The backlog must be more than 0'))
bind_addr = (host, port)
# TODO(dims): eventlet's green dns/socket module does not actually
# support IPv6 in getaddrinfo(). We need to get around this in the
# future or monitor upstream for a fix
info = socket.getaddrinfo(bind_addr[0],
family = info[0]
bind_addr = info[-1]
except Exception:
family = socket.AF_INET
self._socket = eventlet.listen(bind_addr, family, backlog=backlog)
except EnvironmentError:
LOG.error("Could not bind to %(host)s:%(port)s",
{'host': host, 'port': port})
(, self.port) = self._socket.getsockname()[0:2]"%(name)s listening on %(host)s:%(port)s",
{'name':, 'host':, 'port': self.port})
def start(self):
"""Start serving a WSGI application.
:returns: None
# The server socket object will be closed after server exits,
# but the underlying file descriptor will remain open, and will
# give bad file descriptor error. So duplicating the socket object,
# to keep file descriptor usable.
dup_socket = self._socket.dup()
socket.SO_REUSEADDR, 1)
# sockets can hang around forever without keepalive
socket.SO_KEEPALIVE, 1)
# This option isn't available in the OS X version of eventlet
if hasattr(socket, 'TCP_KEEPIDLE'):
if self._use_ssl:
ca_file = CONF.wsgi.ssl_ca_file
cert_file = CONF.wsgi.ssl_cert_file
key_file = CONF.wsgi.ssl_key_file
if cert_file and not os.path.exists(cert_file):
raise RuntimeError(
_("Unable to find cert_file : %s") % cert_file)
if ca_file and not os.path.exists(ca_file):
raise RuntimeError(
_("Unable to find ca_file : %s") % ca_file)
if key_file and not os.path.exists(key_file):
raise RuntimeError(
_("Unable to find key_file : %s") % key_file)
if self._use_ssl and (not cert_file or not key_file):
raise RuntimeError(
_("When running server in SSL mode, you must "
"specify both a cert_file and key_file "
"option value in your configuration file"))
ssl_kwargs = {
'server_side': True,
'certfile': cert_file,
'keyfile': key_file,
'cert_reqs': ssl.CERT_NONE,
if CONF.wsgi.ssl_ca_file:
ssl_kwargs['ca_certs'] = ca_file
ssl_kwargs['cert_reqs'] = ssl.CERT_REQUIRED
dup_socket = eventlet.wrap_ssl(dup_socket,
except Exception:
with excutils.save_and_reraise_exception():
"Failed to start %(name)s on %(host)s:%(port)s with "
"SSL support",
{'name':, 'host':,
'port': self.port})
wsgi_kwargs = {
'func': eventlet.wsgi.server,
'sock': dup_socket,
'protocol': self._protocol,
'custom_pool': self._pool,
'log': self._logger,
'log_format': CONF.wsgi.wsgi_log_format,
'debug': False,
'keepalive': CONF.wsgi.keep_alive,
'socket_timeout': self.client_socket_timeout
if self._max_url_len:
wsgi_kwargs['url_length_limit'] = self._max_url_len
self._server = utils.spawn(**wsgi_kwargs)
def reset(self):
"""Reset server greenpool size to default.
:returns: None
def stop(self):
"""Stop this server.
This is not a very nice action, as currently the method by which a
server is stopped is by killing its eventlet.
:returns: None
""""Stopping WSGI server.")
if self._server is not None:
# Resize pool to stop new requests from being processed
def wait(self):
"""Block, until the server has stopped.
Waits on the server's eventlet to finish, then returns.
:returns: None
if self._server is not None:
except greenlet.GreenletExit:"WSGI server has stopped.")
class WSGIService(service.Service):
"""Provides ability to launch API from a 'paste' configuration."""
def __init__(self, name, loader=None, use_ssl=False, max_url_len=None):
"""Initialize, but do not start the WSGI server.
:param name: The name of the WSGI server given to the loader.
:param loader: Loads the WSGI application using the given name.
:returns: None
""" = name
# NOTE(danms): Name can be metadata, osapi_compute, per
# nova.service's enabled_apis
self.binary = 'nova-%s' % name
LOG.warning('Running %s using eventlet is deprecated. Deploy with '
'a WSGI server such as uwsgi or mod_wsgi.', self.binary)
self.topic = None
self.manager = self._get_manager()
self.loader = loader or api_wsgi.Loader() = self.loader.load_app(name)
# inherit all compute_api worker counts from osapi_compute
if name.startswith('openstack_compute_api'):
wname = 'osapi_compute'
wname = name = getattr(CONF, '%s_listen' % name, "")
self.port = getattr(CONF, '%s_listen_port' % name, 0)
self.workers = (getattr(CONF, '%s_workers' % wname, None) or
if self.workers and self.workers < 1:
worker_name = '%s_workers' % name
msg = (_("%(worker_name)s value of %(workers)s is invalid, "
"must be greater than 0") %
{'worker_name': worker_name,
'workers': str(self.workers)})
raise exception.InvalidInput(msg)
self.use_ssl = use_ssl
self.server = WSGIServer(
# Pull back actual port used
self.port = self.server.port
self.backdoor_port = None
def reset(self):
"""Reset the following:
* server greenpool size to default
* service version cache
* cell cache holding database transaction context managers
:returns: None
context.CELL_CACHE = {}
def _get_manager(self):
"""Initialize a Manager object appropriate for this service.
Use the service name to look up a Manager subclass from the
configuration and initialize an instance. If no class name
is configured, just return None.
:returns: a Manager instance, or None.
manager = SERVICE_MANAGERS.get(self.binary)
if manager is None:
return None
manager_class = importutils.import_class(manager)
return manager_class()
def start(self):
"""Start serving this service using loaded configuration.
Also, retrieve updated port number in case '0' was passed in, which
indicates a random port should be used.
:returns: None
# NOTE(melwitt): Clear the cell cache holding database transaction
# context manager objects. We do this to ensure we create new internal
# oslo.db locks to avoid a situation where a child process receives an
# already locked oslo.db lock when it is forked. When a child process
# inherits a locked oslo.db lock, database accesses through that
# transaction context manager will never be able to acquire the lock
# and requests will fail with CellTimeout errors.
# See for more information.
# With python 3.7, it would be possible for oslo.db to make use of the
# os.register_at_fork() method to reinitialize its lock. Until we
# require python 3.7 as a minimum version, we must handle the situation
# outside of oslo.db.
context.CELL_CACHE = {}
ctxt = context.get_admin_context()
service_ref = objects.Service.get_by_host_and_binary(ctxt,,
if service_ref:
service_ref = _create_service_ref(self, ctxt)
except (exception.ServiceTopicExists,
# NOTE(danms): If we race to create a record with a sibling,
# don't fail here.
service_ref = objects.Service.get_by_host_and_binary(
ctxt,, self.binary)
self.service_ref = service_ref
if self.manager:
if self.backdoor_port is not None:
self.manager.backdoor_port = self.backdoor_port
if self.manager:
def stop(self):
"""Stop serving this API.
:returns: None
def wait(self):
"""Wait for the service to stop serving this API.
:returns: None
def process_launcher():
return service.ProcessLauncher(CONF, restart_method='mutate')
# NOTE(vish): the global launcher is to maintain the existing
# functionality of calling service.serve +
# service.wait
_launcher = None
def serve(server, workers=None):
global _launcher
if _launcher:
raise RuntimeError(_('serve() can only be called once'))
_launcher = service.launch(CONF, server, workers=workers,
def wait():