Try to restart when receiving SIGHUP (issue #26) Seems to not always work when

running detached.)

celery/bin/celeryd.py

@@ -80,6 +80,7 @@ from celery import conf
 from celery import discovery
 from celery.task import discard_all
 from celery.worker import WorkController
+from signal import signal, SIGHUP
 import multiprocessing
 import traceback
 import optparse
@@ -254,11 +255,16 @@ def run_worker(concurrency=DAEMON_CONCURRENCY, detach=False,
     # (Usually imports task modules and such.)
     current_loader.on_worker_init()
 
+
     def run_worker():
         worker = WorkController(concurrency=concurrency,
                                 loglevel=loglevel,
                                 logfile=logfile,
                                 is_detached=detach)
+
+        # Install signal handler that restarts celeryd on SIGHUP
+        install_restart_signal_handler(worker)
+
         try:
             worker.start()
         except Exception, e:
@@ -276,6 +282,27 @@ def run_worker(concurrency=DAEMON_CONCURRENCY, detach=False,
         raise
 
 
+def install_restart_signal_handler(worker):
+    """Installs a signal handler that restarts the current program
+    when it receives the ``SIGHUP`` signal.
+    """
+
+    def restart_self(signum, frame):
+        """Signal handler restarting the current python program."""
+        worker.logger.info("Restarting celeryd (%s)" % (
+            " ".join(sys.argv)))
+        if worker.is_detached:
+            pid = os.fork()
+            if pid:
+                worker.stop()
+                sys.exit(0)
+        else:
+            worker.stop()
+        os.execve(sys.executable, [sys.executable] + sys.argv, os.environ)
+
+    signal(SIGHUP, restart_self)
+
+
 def parse_options(arguments):
     """Parse the available options to ``celeryd``."""
     parser = optparse.OptionParser(option_list=OPTION_LIST)

celery/worker/__init__.py

@@ -5,7 +5,7 @@ The Multiprocessing Worker Server
 Documentation for this module is in ``docs/reference/celery.worker.rst``.
 
 """
-from carrot.connection import DjangoBrokerConnection
+from carrot.connection import DjangoBrokerConnection, AMQPConnectionException
 from celery.worker.controllers import Mediator, PeriodicWorkController
 from celery.worker.job import TaskWrapper
 from celery.registry import NotRegistered
@@ -65,8 +65,7 @@ class AMQPListener(object):
             self.reset_connection()
             try:
                 self.consume_messages()
-            except (socket.error,
-                    self.amqp_connection.ConnectionException):
+            except (socket.error, AMQPConnectionException):
                 self.logger.error("AMQPListener: Connection to broker lost. "
                                 + "Trying to re-establish connection...")
 
@@ -299,3 +298,5 @@ class WorkController(object):
             return
 
         [component.stop() for component in reversed(self.components)]
+
+        self._state = "STOP"