# 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 errno import inspect import os import random import signal import sys import time import eventlet import greenlet from oslo_config import cfg from oslo_log import log import oslo_messaging as messaging from oslo_service import loopingcall from oslo_utils import importutils from manila import context from manila import db from manila import exception from manila.i18n import _LE from manila.i18n import _LI from manila.i18n import _LW from manila import rpc from manila import version from manila import wsgi LOG = log.getLogger(__name__) service_opts = [ cfg.IntOpt('report_interval', default=10, help='Seconds between nodes reporting state to datastore.'), cfg.IntOpt('periodic_interval', default=60, help='Seconds between running 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.StrOpt('osapi_share_listen', default="0.0.0.0", help='IP address for OpenStack Share API to listen on.'), cfg.IntOpt('osapi_share_listen_port', default=8786, help='Port for OpenStack Share API to listen on.'), ] CONF = cfg.CONF CONF.register_opts(service_opts) class SignalExit(SystemExit): def __init__(self, signo, exccode=1): super(SignalExit, self).__init__(exccode) self.signo = signo class Launcher(object): """Launch one or more services and wait for them to complete.""" def __init__(self): """Initialize the service launcher. :returns: None """ self._services = [] @staticmethod def run_server(server): """Start and wait for a server to finish. :param service: Server to run and wait for. :returns: None """ server.start() server.wait() def launch_server(self, server): """Load and start the given server. :param server: The server you would like to start. :returns: None """ gt = eventlet.spawn(self.run_server, server) self._services.append(gt) def stop(self): """Stop all services which are currently running. :returns: None """ for service in self._services: service.kill() def wait(self): """Waits until all services have been stopped, and then returns. :returns: None """ def sigterm(sig, frame): LOG.info(_LI("SIGTERM received")) # NOTE(jk0): Raise a ^C which is caught by the caller and cleanly # shuts down the service. This does not yet handle eventlet # threads. raise KeyboardInterrupt signal.signal(signal.SIGTERM, sigterm) for service in self._services: try: service.wait() except greenlet.GreenletExit: pass class ServerWrapper(object): def __init__(self, server, workers): self.server = server self.workers = workers self.children = set() self.forktimes = [] self.failed = False class ProcessLauncher(object): def __init__(self): self.children = {} self.sigcaught = None self.totalwrap = 0 self.failedwrap = 0 self.running = True rfd, self.writepipe = os.pipe() self.readpipe = eventlet.greenio.GreenPipe(rfd, 'r') signal.signal(signal.SIGTERM, self._handle_signal) signal.signal(signal.SIGINT, self._handle_signal) def _handle_signal(self, signo, frame): self.sigcaught = signo self.running = False # Allow the process to be killed again and die from natural causes signal.signal(signal.SIGTERM, signal.SIG_DFL) signal.signal(signal.SIGINT, signal.SIG_DFL) def _pipe_watcher(self): # This will block until the write end is closed when the parent # dies unexpectedly self.readpipe.read() LOG.info(_LI('Parent process has died unexpectedly, exiting')) sys.exit(1) def _child_process(self, server): # Setup child signal handlers differently def _sigterm(*args): signal.signal(signal.SIGTERM, signal.SIG_DFL) raise SignalExit(signal.SIGTERM) signal.signal(signal.SIGTERM, _sigterm) # Block SIGINT and let the parent send us a SIGTERM # signal.signal(signal.SIGINT, signal.SIG_IGN) # This differs from the behavior in nova in that we dont ignore this # It allows the non-wsgi services to be terminated properly signal.signal(signal.SIGINT, _sigterm) # Reopen the eventlet hub to make sure we don't share an epoll # fd with parent and/or siblings, which would be bad eventlet.hubs.use_hub() # Close write to ensure only parent has it open os.close(self.writepipe) # Create greenthread to watch for parent to close pipe eventlet.spawn(self._pipe_watcher) # Reseed random number generator random.seed() launcher = Launcher() launcher.run_server(server) def _start_child(self, wrap): if len(wrap.forktimes) > wrap.workers: # Limit ourselves to one process a second (over the period of # number of workers * 1 second). This will allow workers to # start up quickly but ensure we don't fork off children that # die instantly too quickly. if time.time() - wrap.forktimes[0] < wrap.workers: LOG.info(_LI('Forking too fast, sleeping')) time.sleep(1) wrap.forktimes.pop(0) wrap.forktimes.append(time.time()) pid = os.fork() if pid == 0: # NOTE(johannes): All exceptions are caught to ensure this # doesn't fallback into the loop spawning children. It would # be bad for a child to spawn more children. status = 0 try: self._child_process(wrap.server) except SignalExit as exc: signame = {signal.SIGTERM: 'SIGTERM', signal.SIGINT: 'SIGINT'}[exc.signo] LOG.info(_LI('Caught %s, exiting'), signame) status = exc.code except SystemExit as exc: status = exc.code except BaseException: LOG.exception(_LE('Unhandled exception')) status = 2 finally: wrap.server.stop() os._exit(status) LOG.info(_LI('Started child %d'), pid) wrap.children.add(pid) self.children[pid] = wrap return pid def launch_server(self, server, workers=1): wrap = ServerWrapper(server, workers) self.totalwrap = self.totalwrap + 1 LOG.info(_LI('Starting %d workers'), wrap.workers) while (self.running and len(wrap.children) < wrap.workers and not wrap.failed): self._start_child(wrap) def _wait_child(self): try: # Don't block if no child processes have exited pid, status = os.waitpid(0, os.WNOHANG) if not pid: return None except OSError as exc: if exc.errno not in (errno.EINTR, errno.ECHILD): raise return None code = 0 if os.WIFSIGNALED(status): sig = os.WTERMSIG(status) LOG.info(_LI('Child %(pid)d killed by signal %(sig)d'), {'pid': pid, 'sig': sig}) else: code = os.WEXITSTATUS(status) LOG.info(_LI('Child %(pid)d exited with status %(code)d'), {'pid': pid, 'code': code}) if pid not in self.children: LOG.warning(_LW('pid %d not in child list'), pid) return None wrap = self.children.pop(pid) wrap.children.remove(pid) if 2 == code: wrap.failed = True self.failedwrap = self.failedwrap + 1 LOG.info(_LI('_wait_child %d'), self.failedwrap) if self.failedwrap == self.totalwrap: self.running = False return wrap def wait(self): """Loop waiting on children to die and respawning as necessary.""" while self.running: wrap = self._wait_child() if not wrap: # Yield to other threads if no children have exited # Sleep for a short time to avoid excessive CPU usage # (see bug #1095346) eventlet.greenthread.sleep(.01) continue LOG.info(_LI('wait wrap.failed %s'), wrap.failed) while (self.running and len(wrap.children) < wrap.workers and not wrap.failed): self._start_child(wrap) if self.sigcaught: signame = {signal.SIGTERM: 'SIGTERM', signal.SIGINT: 'SIGINT'}[self.sigcaught] LOG.info(_LI('Caught %s, stopping children'), signame) for pid in self.children: try: os.kill(pid, signal.SIGTERM) except OSError as exc: if exc.errno != errno.ESRCH: raise # Wait for children to die if self.children: LOG.info(_LI('Waiting on %d children to exit'), len(self.children)) while self.children: self._wait_child() class Service(object): """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. """ def __init__(self, host, binary, topic, manager, report_interval=None, periodic_interval=None, periodic_fuzzy_delay=None, service_name=None, *args, **kwargs): super(Service, self).__init__() if not rpc.initialized(): rpc.init(CONF) self.host = host self.binary = binary self.topic = topic self.manager_class_name = manager manager_class = importutils.import_class(self.manager_class_name) self.manager = manager_class(host=self.host, service_name=service_name, *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 = [] def start(self): version_string = version.version_string() LOG.info(_LI('Starting %(topic)s node (version %(version_string)s)'), {'topic': self.topic, 'version_string': version_string}) self.model_disconnected = False ctxt = context.get_admin_context() try: service_ref = db.service_get_by_args(ctxt, self.host, self.binary) self.service_id = service_ref['id'] except exception.NotFound: self._create_service_ref(ctxt) LOG.debug("Creating RPC server for service %s.", self.topic) target = messaging.Target(topic=self.topic, server=self.host) endpoints = [self.manager] endpoints.extend(self.manager.additional_endpoints) self.rpcserver = rpc.get_server(target, endpoints) self.rpcserver.start() self.manager.init_host() 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) def _create_service_ref(self, context): zone = CONF.storage_availability_zone service_ref = db.service_create(context, {'host': self.host, 'binary': self.binary, 'topic': self.topic, 'report_count': 0, 'availability_zone': zone}) self.service_id = service_ref['id'] 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, service_name=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 - 'manila-' part :param manager: defaults to CONF._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 if not manager: subtopic = topic.rpartition('manila-')[2] manager = CONF.get('%s_manager' % subtopic, 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, service_name=service_name) return service_obj def kill(self): """Destroy the service object in the datastore.""" self.stop() try: db.service_destroy(context.get_admin_context(), self.service_id) except exception.NotFound: LOG.warn(_LW('Service killed that has no database entry')) def stop(self): # Try to shut the connection down, but if we get any sort of # errors, go ahead and ignore them.. as we're shutting down anyway try: self.rpcserver.stop() except Exception: pass for x in self.timers: try: x.stop() except Exception: pass self.timers = [] def wait(self): for x in self.timers: try: x.wait() except Exception: pass 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 in the datastore.""" ctxt = context.get_admin_context() zone = CONF.storage_availability_zone state_catalog = {} try: try: service_ref = db.service_get(ctxt, self.service_id) except exception.NotFound: LOG.debug('The service database object disappeared, ' 'Recreating it.') self._create_service_ref(ctxt) service_ref = db.service_get(ctxt, self.service_id) state_catalog['report_count'] = service_ref['report_count'] + 1 if zone != service_ref['availability_zone']: state_catalog['availability_zone'] = zone db.service_update(ctxt, self.service_id, state_catalog) # TODO(termie): make this pattern be more elegant. if getattr(self, 'model_disconnected', False): self.model_disconnected = False LOG.error(_LE('Recovered model server connection!')) # TODO(vish): this should probably only catch connection errors except Exception: # pylint: disable=W0702 if not getattr(self, 'model_disconnected', False): self.model_disconnected = True LOG.exception(_LE('model server went away')) class WSGIService(object): """Provides ability to launch API from a 'paste' configuration.""" def __init__(self, name, loader=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() if not rpc.initialized(): rpc.init(CONF) 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.server = wsgi.Server(name, self.app, host=self.host, port=self.port) 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() 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.server.start() self.port = self.server.port def stop(self): """Stop serving this API. :returns: None """ self.server.stop() def wait(self): """Wait for the service to stop serving this API. :returns: None """ self.server.wait() # NOTE(vish): the global launcher is to maintain the existing # functionality of calling service.serve + # service.wait _launcher = None def serve(*servers): global _launcher if not _launcher: _launcher = Launcher() for server in servers: _launcher.launch_server(server) def wait(): LOG.debug('Full set of CONF:') for flag in CONF: flag_get = CONF.get(flag, None) # hide flag contents from log if contains a password # should use secret flag when switch over to openstack-common if ("_password" in flag or "_key" in flag or (flag == "sql_connection" and "mysql:" in flag_get)): LOG.debug('%(flag)s : FLAG SET ', {"flag": flag}) else: LOG.debug('%(flag)s : %(flag_get)s', {"flag": flag, "flag_get": flag_get}) try: _launcher.wait() except KeyboardInterrupt: _launcher.stop() rpc.cleanup()