Source code for watcher.common.service

# -*- encoding: utf-8 -*-
#
# Copyright © 2012 eNovance <licensing@enovance.com>
##
# 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 logging
import socket

from oslo_concurrency import processutils
from oslo_config import cfg
from oslo_log import _options
from oslo_log import log
import oslo_messaging as om
from oslo_reports import guru_meditation_report as gmr
from oslo_reports import opts as gmr_opts
from oslo_service import service
from oslo_service import wsgi

from watcher._i18n import _, _LI
from watcher.api import app
from watcher.common import config
from watcher.common.messaging.events import event_dispatcher as dispatcher
from watcher.common.messaging import messaging_handler
from watcher.common import rpc
from watcher.objects import base
from watcher import opts
from watcher import version

service_opts = [
    cfg.IntOpt('periodic_interval',
               default=60,
               help=_('Seconds between running periodic tasks.')),
    cfg.StrOpt('host',
               default=socket.getfqdn(),
               help=_('Name of this node. This can be an opaque identifier.  '
                      'It is not necessarily a hostname, FQDN, or IP address. '
                      'However, the node name must be valid within '
                      'an AMQP key, and if using ZeroMQ, a valid '
                      'hostname, FQDN, or IP address.')),
]

cfg.CONF.register_opts(service_opts)

CONF = cfg.CONF
LOG = log.getLogger(__name__)

_DEFAULT_LOG_LEVELS = ['amqp=WARN', 'amqplib=WARN', 'qpid.messaging=INFO',
                       'oslo.messaging=INFO', 'sqlalchemy=WARN',
                       'keystoneclient=INFO', 'stevedore=INFO',
                       'eventlet.wsgi.server=WARN', 'iso8601=WARN',
                       'paramiko=WARN', 'requests=WARN', 'neutronclient=WARN',
                       'glanceclient=WARN', 'watcher.openstack.common=WARN']

Singleton = service.Singleton


[docs]class WSGIService(service.ServiceBase): """Provides ability to launch Watcher API from wsgi app.""" def __init__(self, name, use_ssl=False): """Initialize, but do not start the WSGI server. :param name: The name of the WSGI server given to the loader. :param use_ssl: Wraps the socket in an SSL context if True. """ self.name = name self.app = app.VersionSelectorApplication() self.workers = (CONF.api.workers or processutils.get_worker_count()) self.server = wsgi.Server(CONF, name, self.app, host=CONF.api.host, port=CONF.api.port, use_ssl=use_ssl, logger_name=name)
[docs] def start(self): """Start serving this service using loaded configuration""" self.server.start()
[docs] def stop(self): """Stop serving this API""" self.server.stop()
[docs] def wait(self): """Wait for the service to stop serving this API""" self.server.wait()
[docs] def reset(self): """Reset server greenpool size to default""" self.server.reset()
[docs]class Service(service.ServiceBase, dispatcher.EventDispatcher): API_VERSION = '1.0' def __init__(self, manager_class): super(Service, self).__init__() self.manager = manager_class() self.publisher_id = self.manager.publisher_id self.api_version = self.manager.API_VERSION self.conductor_topic = self.manager.conductor_topic self.status_topic = self.manager.status_topic self.notification_topics = self.manager.notification_topics self.conductor_endpoints = [ ep(self) for ep in self.manager.conductor_endpoints ] self.status_endpoints = [ ep(self.publisher_id) for ep in self.manager.status_endpoints ] self.notification_endpoints = self.manager.notification_endpoints self.serializer = rpc.RequestContextSerializer( base.WatcherObjectSerializer()) self._transport = None self._notification_transport = None self._conductor_client = None self._status_client = None self.conductor_topic_handler = None self.status_topic_handler = None self.notification_handler = None if self.conductor_topic and self.conductor_endpoints: self.conductor_topic_handler = self.build_topic_handler( self.conductor_topic, self.conductor_endpoints) if self.status_topic and self.status_endpoints: self.status_topic_handler = self.build_topic_handler( self.status_topic, self.status_endpoints) if self.notification_topics and self.notification_endpoints: self.notification_handler = self.build_notification_handler( self.notification_topics, self.notification_endpoints ) @property def transport(self): if self._transport is None: self._transport = om.get_transport(CONF) return self._transport @property def notification_transport(self): if self._notification_transport is None: self._notification_transport = om.get_notification_transport(CONF) return self._notification_transport @property def conductor_client(self): if self._conductor_client is None: target = om.Target( topic=self.conductor_topic, version=self.API_VERSION, ) self._conductor_client = om.RPCClient( self.transport, target, serializer=self.serializer) return self._conductor_client @conductor_client.setter def conductor_client(self, c): self.conductor_client = c @property def status_client(self): if self._status_client is None: target = om.Target( topic=self.status_topic, version=self.API_VERSION, ) self._status_client = om.RPCClient( self.transport, target, serializer=self.serializer) return self._status_client @status_client.setter def status_client(self, c): self.status_client = c
[docs] def build_topic_handler(self, topic_name, endpoints=()): return messaging_handler.MessagingHandler( self.publisher_id, topic_name, [self.manager] + list(endpoints), self.api_version, self.serializer)
[docs] def build_notification_handler(self, topic_names, endpoints=()): serializer = rpc.RequestContextSerializer(rpc.JsonPayloadSerializer()) targets = [om.Target(topic=topic_name) for topic_name in topic_names] return om.get_notification_listener( self.notification_transport, targets, endpoints, executor='eventlet', serializer=serializer, allow_requeue=False)
[docs] def start(self): LOG.debug("Connecting to '%s' (%s)", CONF.transport_url, CONF.rpc_backend) if self.conductor_topic_handler: self.conductor_topic_handler.start() if self.status_topic_handler: self.status_topic_handler.start() if self.notification_handler: self.notification_handler.start()
[docs] def stop(self): LOG.debug("Disconnecting from '%s' (%s)", CONF.transport_url, CONF.rpc_backend) if self.conductor_topic_handler: self.conductor_topic_handler.stop() if self.status_topic_handler: self.status_topic_handler.stop() if self.notification_handler: self.notification_handler.stop()
[docs] def reset(self): """Reset a service in case it received a SIGHUP."""
[docs] def wait(self): """Wait for service to complete."""
[docs] def publish_control(self, event, payload): return self.conductor_topic_handler.publish_event(event, payload)
[docs] def publish_status_event(self, event, payload, request_id=None): if self.status_topic_handler: return self.status_topic_handler.publish_event( event, payload, request_id) else: LOG.info( _LI("No status notifier declared: notification '%s' not sent"), event)
[docs] def get_version(self): return self.api_version
[docs] def check_api_version(self, context): api_manager_version = self.conductor_client.call( context.to_dict(), 'check_api_version', api_version=self.api_version) return api_manager_version
[docs] def response(self, evt, ctx, message): payload = { 'request_id': ctx['request_id'], 'msg': message } self.publish_status_event(evt, payload)
def launch(conf, service_, workers=1, restart_method='reload'): return service.launch(conf, service_, workers, restart_method) def prepare_service(argv=(), conf=cfg.CONF): log.register_options(conf) gmr_opts.set_defaults(conf) config.parse_args(argv) cfg.set_defaults(_options.log_opts, default_log_levels=_DEFAULT_LOG_LEVELS) log.setup(conf, 'python-watcher') conf.log_opt_values(LOG, logging.DEBUG) gmr.TextGuruMeditation.register_section(_('Plugins'), opts.show_plugins) gmr.TextGuruMeditation.setup_autorun(version, conf=conf)

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