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OpenStack Study: service.py**** CubicPower OpenStack Study ****
# 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 # # 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. """Generic Node base class for all workers that run on hosts.""" import os import random import sys from oslo.config import cfg from oslo import messaging from nova import baserpc from nova import conductor from nova import context from nova import debugger from nova import exception from nova.objects import base as objects_base from nova.openstack.common.gettextutils import _ from nova.openstack.common import importutils from nova.openstack.common import log as logging from nova.openstack.common import service from nova import rpc from nova import servicegroup from nova import utils from nova import version from nova import wsgi LOG = logging.getLogger(__name__) service_opts = [ cfg.IntOpt('report_interval', default=10, help='Seconds between nodes reporting state to datastore'), cfg.BoolOpt('periodic_enable', default=True, help='Enable periodic tasks'), cfg.IntOpt('periodic_fuzzy_delay', default=60, help='Range of seconds to randomly delay when starting the' ' periodic task scheduler to reduce stampeding.' ' (Disable by setting to 0)'), cfg.ListOpt('enabled_apis', default=['ec2', 'osapi_compute', 'metadata'], help='A list of APIs to enable by default'), cfg.ListOpt('enabled_ssl_apis', default=[], help='A list of APIs with enabled SSL'), cfg.StrOpt('ec2_listen', default="0.0.0.0", help='The IP address on which the EC2 API will listen.'), cfg.IntOpt('ec2_listen_port', default=8773, help='The port on which the EC2 API will listen.'), cfg.IntOpt('ec2_workers', help='Number of workers for EC2 API service. The default will ' 'be equal to the number of CPUs available.'), cfg.StrOpt('osapi_compute_listen', default="0.0.0.0", help='The IP address on which the OpenStack API will listen.'), cfg.IntOpt('osapi_compute_listen_port', default=8774, help='The port on which the OpenStack API will listen.'), cfg.IntOpt('osapi_compute_workers', help='Number of workers for OpenStack API service. The default ' 'will be the number of CPUs available.'), cfg.StrOpt('metadata_manager', default='nova.api.manager.MetadataManager', help='OpenStack metadata service manager'), cfg.StrOpt('metadata_listen', default="0.0.0.0", help='The IP address on which the metadata API will listen.'), cfg.IntOpt('metadata_listen_port', default=8775, help='The port on which the metadata API will listen.'), cfg.IntOpt('metadata_workers', help='Number of workers for metadata service. The default will ' 'be the number of CPUs available.'), cfg.StrOpt('compute_manager', default='nova.compute.manager.ComputeManager', help='Full class name for the Manager for compute'), cfg.StrOpt('console_manager', default='nova.console.manager.ConsoleProxyManager', help='Full class name for the Manager for console proxy'), cfg.StrOpt('consoleauth_manager', default='nova.consoleauth.manager.ConsoleAuthManager', help='Manager for console auth'), cfg.StrOpt('cert_manager', default='nova.cert.manager.CertManager', help='Full class name for the Manager for cert'), cfg.StrOpt('network_manager', default='nova.network.manager.VlanManager', help='Full class name for the Manager for network'), cfg.StrOpt('scheduler_manager', default='nova.scheduler.manager.SchedulerManager', help='Full class name for the Manager for scheduler'), cfg.IntOpt('service_down_time', default=60, help='Maximum time since last check-in for up service'), ] CONF = cfg.CONF CONF.register_opts(service_opts) CONF.import_opt('host', 'nova.netconf')
**** CubicPower OpenStack Study **** 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 it state to the database services table. """
**** CubicPower OpenStack Study **** def __init__(self, host, binary, topic, manager, report_interval=None, periodic_enable=None, periodic_fuzzy_delay=None, periodic_interval_max=None, db_allowed=True, *args, **kwargs): super(Service, self).__init__() self.host = host self.binary = binary self.topic = topic self.manager_class_name = manager # NOTE(russellb) We want to make sure to create the servicegroup API # instance early, before creating other things such as the manager, # that will also create a servicegroup API instance. Internally, the # servicegroup only allocates a single instance of the driver API and # we want to make sure that our value of db_allowed is there when it # gets created. For that to happen, this has to be the first instance # of the servicegroup API. self.servicegroup_api = servicegroup.API(db_allowed=db_allowed) manager_class = importutils.import_class(self.manager_class_name) self.manager = manager_class(host=self.host, *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 self.conductor_api = conductor.API(use_local=db_allowed) self.conductor_api.wait_until_ready(context.get_admin_context())
**** CubicPower OpenStack Study **** def start(self): verstr = version.version_string_with_package() LOG.audit(_('Starting %(topic)s node (version %(version)s)'), {'topic': self.topic, 'version': verstr}) self.basic_config_check() self.manager.init_host() self.model_disconnected = False ctxt = context.get_admin_context() try: self.service_ref = self.conductor_api.service_get_by_args(ctxt, self.host, self.binary) self.service_id = self.service_ref['id'] except exception.NotFound: try: self.service_ref = self._create_service_ref(ctxt) except exception.ServiceTopicExists: # NOTE(danms): If we race to create a record with a sibling # worker, don't fail here. self.service_ref = self.conductor_api.service_get_by_args(ctxt, self.host, self.binary) self.manager.pre_start_hook() 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, server=self.host) endpoints = [ self.manager, baserpc.BaseRPCAPI(self.manager.service_name, self.backdoor_port) ] endpoints.extend(self.manager.additional_endpoints) serializer = objects_base.NovaObjectSerializer() self.rpcserver = rpc.get_server(target, endpoints, serializer) self.rpcserver.start() self.manager.post_start_hook() LOG.debug(_("Join ServiceGroup membership for this service %s") % self.topic) # Add service to the ServiceGroup membership group. self.servicegroup_api.join(self.host, self.topic, self) if self.periodic_enable: if self.periodic_fuzzy_delay: initial_delay = random.randint(0, self.periodic_fuzzy_delay) else: initial_delay = None self.tg.add_dynamic_timer(self.periodic_tasks, initial_delay=initial_delay, periodic_interval_max= self.periodic_interval_max)
**** CubicPower OpenStack Study **** def _create_service_ref(self, context): svc_values = { 'host': self.host, 'binary': self.binary, 'topic': self.topic, 'report_count': 0 } service = self.conductor_api.service_create(context, svc_values) self.service_id = service['id'] return service
**** CubicPower OpenStack Study **** def __getattr__(self, key): manager = self.__dict__.get('manager', None) return getattr(manager, key) @classmethod
**** CubicPower OpenStack Study **** 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, db_allowed=True): """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 - 'nova-' part :param manager: defaults to CONF. :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 = CONF.host if not binary: binary = os.path.basename(sys.argv[0]) if not topic: topic = binary.rpartition('nova-')[2] if not manager: manager_cls = ('%s_manager' % binary.rpartition('nova-')[2]) manager = CONF.get(manager_cls, None) 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 debugger.init() service_obj = cls(host, binary, topic, manager, report_interval=report_interval, periodic_enable=periodic_enable, periodic_fuzzy_delay=periodic_fuzzy_delay, periodic_interval_max=periodic_interval_max, db_allowed=db_allowed) return service_obj
**** CubicPower OpenStack Study **** def kill(self): """Destroy the service object in the datastore.""" self.stop() try: self.conductor_api.service_destroy(context.get_admin_context(), self.service_id) except exception.NotFound: LOG.warn(_('Service killed that has no database entry'))
**** CubicPower OpenStack Study **** def stop(self): try: self.rpcserver.stop() self.rpcserver.wait() except Exception: pass try: self.manager.cleanup_host() except Exception: LOG.exception(_('Service error occurred during cleanup_host')) pass super(Service, self).stop()
**** CubicPower OpenStack Study **** 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)
**** CubicPower OpenStack Study **** def basic_config_check(self): """Perform basic config checks before starting processing.""" # Make sure the tempdir exists and is writable try: with utils.tempdir(): pass except Exception as e: LOG.error(_('Temporary directory is invalid: %s'), e) sys.exit(1)
**** CubicPower OpenStack Study **** class WSGIService(object): """Provides ability to launch API from a 'paste' configuration."""
**** CubicPower OpenStack Study **** 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 """ self.name = name self.manager = self._get_manager() self.loader = loader or wsgi.Loader() self.app = self.loader.load_app(name) self.host = getattr(CONF, '%s_listen' % name, "0.0.0.0") self.port = getattr(CONF, '%s_listen_port' % name, 0) self.workers = (getattr(CONF, '%s_workers' % name, None) or utils.cpu_count()) 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 = wsgi.Server(name, self.app, host=self.host, port=self.port, use_ssl=self.use_ssl, max_url_len=max_url_len) # Pull back actual port used self.port = self.server.port self.backdoor_port = None
**** CubicPower OpenStack Study **** 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. """ fl = '%s_manager' % self.name if fl not in CONF: return None manager_class_name = CONF.get(fl, None) if not manager_class_name: return None manager_class = importutils.import_class(manager_class_name) return manager_class()
**** CubicPower OpenStack Study **** 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 """ if self.manager: self.manager.init_host() self.manager.pre_start_hook() if self.backdoor_port is not None: self.manager.backdoor_port = self.backdoor_port self.server.start() if self.manager: self.manager.post_start_hook()
**** CubicPower OpenStack Study **** def stop(self): """Stop serving this API. :returns: None """ self.server.stop()
**** CubicPower OpenStack Study **** def wait(self): """Wait for the service to stop serving this API. :returns: None """ self.server.wait() def process_launcher(): return service.ProcessLauncher() # 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(server, workers=workers) def wait(): _launcher.wait()
**** CubicPower OpenStack Study **** def process_launcher(): return service.ProcessLauncher() # NOTE(vish): the global launcher is to maintain the existing # functionality of calling service.serve + # service.wait _launcher = None
**** CubicPower OpenStack Study **** def serve(server, workers=None): global _launcher if _launcher: raise RuntimeError(_('serve() can only be called once')) _launcher = service.launch(server, workers=workers)
**** CubicPower OpenStack Study **** def wait(): _launcher.wait()
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