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OpenStack Study: daemon.py**** CubicPower OpenStack Study ****
# Copyright (c) 2010-2012 OpenStack Foundation # # 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 os import sys import time import signal from re import sub import eventlet.debug from swift.common import utils
**** CubicPower OpenStack Study **** class Daemon(object): """Daemon base class"""
**** CubicPower OpenStack Study **** def __init__(self, conf): self.conf = conf self.logger = utils.get_logger(conf, log_route='daemon')
**** CubicPower OpenStack Study **** def run_once(self, *args, **kwargs): """Override this to run the script once""" raise NotImplementedError('run_once not implemented')
**** CubicPower OpenStack Study **** def run_forever(self, *args, **kwargs): """Override this to run forever""" raise NotImplementedError('run_forever not implemented')
**** CubicPower OpenStack Study **** def run(self, once=False, **kwargs): """Run the daemon""" utils.validate_configuration() utils.drop_privileges(self.conf.get('user', 'swift')) utils.capture_stdio(self.logger, **kwargs) def kill_children(*args): signal.signal(signal.SIGTERM, signal.SIG_IGN) os.killpg(0, signal.SIGTERM) sys.exit() signal.signal(signal.SIGTERM, kill_children) if once: self.run_once(**kwargs) else: self.run_forever(**kwargs) def run_daemon(klass, conf_file, section_name='', once=False, **kwargs): """ Loads settings from conf, then instantiates daemon "klass" and runs the daemon with the specified once kwarg. The section_name will be derived from the daemon "klass" if not provided (e.g. ObjectReplicator => object-replicator). :param klass: Class to instantiate, subclass of common.daemon.Daemon :param conf_file: Path to configuration file :param section_name: Section name from conf file to load config from :param once: Passed to daemon run method """ # very often the config section_name is based on the class name # the None singleton will be passed through to readconf as is if section_name is '': section_name = sub(r'([a-z])([A-Z])', r'\1-\2', klass.__name__).lower() conf = utils.readconf(conf_file, section_name, log_name=kwargs.get('log_name')) # once on command line (i.e. daemonize=false) will over-ride config once = once or not utils.config_true_value(conf.get('daemonize', 'true')) # pre-configure logger if 'logger' in kwargs: logger = kwargs.pop('logger') else: logger = utils.get_logger(conf, conf.get('log_name', section_name), log_to_console=kwargs.pop('verbose', False), log_route=section_name) # disable fallocate if desired if utils.config_true_value(conf.get('disable_fallocate', 'no')): utils.disable_fallocate() # set utils.FALLOCATE_RESERVE if desired reserve = int(conf.get('fallocate_reserve', 0)) if reserve > 0: utils.FALLOCATE_RESERVE = reserve # By default, disable eventlet printing stacktraces eventlet_debug = utils.config_true_value(conf.get('eventlet_debug', 'no')) eventlet.debug.hub_exceptions(eventlet_debug) # Ensure TZ environment variable exists to avoid stat('/etc/localtime') on # some platforms. This locks in reported times to the timezone in which # the server first starts running in locations that periodically change # timezones. os.environ['TZ'] = time.strftime("%z", time.gmtime()) try: klass(conf).run(once=once, **kwargs) except KeyboardInterrupt: logger.info('User quit') logger.info('Exited')
**** CubicPower OpenStack Study **** def kill_children(*args): signal.signal(signal.SIGTERM, signal.SIG_IGN) os.killpg(0, signal.SIGTERM) sys.exit() signal.signal(signal.SIGTERM, kill_children) if once: self.run_once(**kwargs) else: self.run_forever(**kwargs) def run_daemon(klass, conf_file, section_name='', once=False, **kwargs): """ Loads settings from conf, then instantiates daemon "klass" and runs the daemon with the specified once kwarg. The section_name will be derived from the daemon "klass" if not provided (e.g. ObjectReplicator => object-replicator). :param klass: Class to instantiate, subclass of common.daemon.Daemon :param conf_file: Path to configuration file :param section_name: Section name from conf file to load config from :param once: Passed to daemon run method """ # very often the config section_name is based on the class name # the None singleton will be passed through to readconf as is if section_name is '': section_name = sub(r'([a-z])([A-Z])', r'\1-\2', klass.__name__).lower() conf = utils.readconf(conf_file, section_name, log_name=kwargs.get('log_name')) # once on command line (i.e. daemonize=false) will over-ride config once = once or not utils.config_true_value(conf.get('daemonize', 'true')) # pre-configure logger if 'logger' in kwargs: logger = kwargs.pop('logger') else: logger = utils.get_logger(conf, conf.get('log_name', section_name), log_to_console=kwargs.pop('verbose', False), log_route=section_name) # disable fallocate if desired if utils.config_true_value(conf.get('disable_fallocate', 'no')): utils.disable_fallocate() # set utils.FALLOCATE_RESERVE if desired reserve = int(conf.get('fallocate_reserve', 0)) if reserve > 0: utils.FALLOCATE_RESERVE = reserve # By default, disable eventlet printing stacktraces eventlet_debug = utils.config_true_value(conf.get('eventlet_debug', 'no')) eventlet.debug.hub_exceptions(eventlet_debug) # Ensure TZ environment variable exists to avoid stat('/etc/localtime') on # some platforms. This locks in reported times to the timezone in which # the server first starts running in locations that periodically change # timezones. os.environ['TZ'] = time.strftime("%z", time.gmtime()) try: klass(conf).run(once=once, **kwargs) except KeyboardInterrupt: logger.info('User quit') logger.info('Exited')
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