def run(self):
""" Run the Daemon. Setup signal handler, task registry, scheduler,
listener and executors. Runs the main control loop.
"""
try:
# setup signal handlers for shutdown or immediate termination
signal(SIGINT, self.shutdown)
signal(SIGTERM, self.terminate)
registry.initialize()
# create executors, listener and scheduler
self.executor_pool = ThreadPool(1)
self.scheduler = Scheduler(self.on_scheduled)
self.listener = get_listener()
self.scheduler.start()
self.reload_schedule()
while True:
try:
conn = self.listener.accept()
except socket.error as exc:
# connection closed
if exc.errno in (errno.EINTR, errno.EBADF):
logger.info(
"Listener interrupted. Exiting main control loop."
)
break
else:
raise
command = None
try:
logger.debug("Client connected: %s", conn)
message = conn.recv()
logger.debug("Received message: %r", message)
command = message[0]
params = message[1:]
if command == "reload":
self.reload_schedule()
elif command == "restart":
job = models.Job.objects.get(id=params[0])
logger.info("Restarting job '%s'" % job)
self.executor_pool.apply_async(
registry.run, [job], job.arguments
)
elif command == "abort":
pass
# TODO: implement
except Exception as exc:
logger.exception("Daemon command %s failed." % command)
finally:
self.shutdown()
class Daemon(object):
""" Multi-purpose task management daemon.
"""
def __init__(self):
self.scheduler = None
self.listener = None
self.executor_pool = None
def run(self):
""" Run the Daemon. Setup signal handler, task registry, scheduler,
listener and executors. Runs the main control loop.
"""
try:
# setup signal handlers for shutdown or immediate termination
signal(SIGINT, self.shutdown)
signal(SIGTERM, self.terminate)
registry.initialize()
# create executors, listener and scheduler
self.executor_pool = ThreadPool(1)
self.scheduler = Scheduler(self.on_scheduled)
self.listener = get_listener()
self.scheduler.start()
self.reload_schedule()
while True:
try:
conn = self.listener.accept()
except socket.error as exc:
# connection closed
if exc.errno in (errno.EINTR, errno.EBADF):
logger.info(
"Listener interrupted. Exiting main control loop."
)
break
else:
raise
command = None
try:
logger.debug("Client connected: %s", conn)
message = conn.recv()
logger.debug("Received message: %r", message)
command = message[0]
params = message[1:]
if command == "reload":
self.reload_schedule()
elif command == "restart":
job = models.Job.objects.get(id=params[0])
logger.info("Restarting job '%s'" % job)
self.executor_pool.apply_async(
registry.run, [job], job.arguments
)
elif command == "abort":
pass
# TODO: implement
except Exception as exc:
logger.exception("Daemon command %s failed." % command)
finally:
self.shutdown()
def shutdown(self, signum=None, frame=None, terminate=False):
""" Shutdown method. When ``terminate`` is ``True``, then the underlying
pool is terminated. Otherwise, running tasks are finished.
"""
if self.executor_pool:
if terminate:
self.executor_pool.terminate()
else:
self.executor_pool.close()
if self.scheduler:
self.scheduler.shutdown()
self.scheduler = None
if self.listener:
self.listener.close()
self.listener = None
def terminate(self, signum=None, frame=None):
self.shutdown(terminate=True)
def on_scheduled(self, scheduled_task):
task = scheduled_task.task
arguments = scheduled_task.argument_values
scheduled_task.delete()
print task, arguments
self.executor_pool.apply_async(run_task, [task], arguments)
def reload_schedule(self):
""" Reload the scheduled items from the database.
"""
self.scheduler.reset()
for scheduled_task in models.ScheduledJob.objects.all():
self.scheduler.schedule(scheduled_task.when, [scheduled_task])
