change stopping tracim strategy: update RQ worker to be stopped and kill tracim process after stop daemons. Closes #166

tracim/tracim/config/app_cfg.py

 
 from tgext.pluggable import plug
 from tgext.pluggable import replace_template
+from tracim.lib.system import InterruptManager
 
 from tracim.lib.utils import lazy_ugettext as l_
 
         manager.run('mail_sender', MailSenderDaemon)
 
 environment_loaded.register(lambda: start_daemons(daemons))
+interrupt_manager = InterruptManager(daemons_manager=daemons)
 
 # Note: here are fake translatable strings that allow to translate messages for reset password email content
 duplicated_email_subject = l_('Password reset request')

tracim/tracim/lib/daemons.py

 import threading
+import collections
 from configparser import DuplicateSectionError
-from wsgiref.simple_server import make_server
-import signal
 
-import collections
+from wsgiref.simple_server import make_server
 
 from radicale import Application as RadicaleApplication
 from radicale import HTTPServer as BaseRadicaleHTTPServer
 from rq import Connection as RQConnection
 from rq import Worker as BaseRQWorker
 from redis import Redis
+from rq.dummy import do_nothing
+from rq.worker import StopRequested
 
 from tracim.lib.base import logger
 from tracim.lib.exceptions import AlreadyRunningDaemon
-from tracim.lib.utils import add_signal_handler
+
+from tracim.tracim.lib.utils import get_rq_queue
 
 
 class DaemonsManager(object):
     def __init__(self):
         self._running_daemons = {}
-        add_signal_handler(signal.SIGTERM, self.stop_all)
 
     def run(self, name: str, daemon_class: object, **kwargs) -> None:
         """
             logger.info(self, 'Stopping daemon with name "{0}": OK'
                               .format(name))
 
-    def stop_all(self, *args, **kwargs) -> None:
+    def stop_all(self) -> None:
         """
         Stop all started daemons and wait for them.
         """
             daemon.stop()
 
         for name, daemon in self._running_daemons.items():
+            logger.info(
+                self,
+                'Stopping daemon "{0}" waiting confirmation'.format(name),
+            )
             daemon.join()
             logger.info(self, 'Stopping daemon "{0}" OK'.format(name))
 
         pass
 
     def stop(self) -> None:
-        self.worker.request_stop('TRACIM STOP', None)
+        # When _stop_requested at False, tracim.tracim.lib.daemons.RQWorker
+        # will raise StopRequested exception in worker thread after receive a
+        # job.
+        self.worker._stop_requested = True
+        queue = get_rq_queue('mail_sender')
+        queue.enqueue(do_nothing)
 
     def run(self) -> None:
         from tracim.config.app_cfg import CFG
 
 class RQWorker(BaseRQWorker):
     def _install_signal_handlers(self):
-        # TODO BS 20170126: RQ WWorker is designed to work in main thread
+        # RQ Worker is designed to work in main thread
         # So we have to disable these signals (we implement server stop in
-        # MailSenderDaemon.stop method). When bug
-        # https://github.com/tracim/tracim/issues/166 will be fixed, ensure
-        # This worker terminate correctly.
+        # MailSenderDaemon.stop method).
         pass
 
+    def dequeue_job_and_maintain_ttl(self, timeout):
+        # RQ Worker is designed to work in main thread, so we add behaviour
+        # here: if _stop_requested has been set to True, raise the standard way
+        # StopRequested exception to stop worker.
+        if self._stop_requested:
+            raise StopRequested()
+        return super().dequeue_job_and_maintain_ttl(timeout)
+
 
 class RadicaleHTTPSServer(TracimSocketServerMixin, BaseRadicaleHTTPSServer):
     pass

tracim/tracim/lib/email.py

 
 import typing
 from mako.template import Template
-from redis import Redis
-from rq import Queue
 from tg.i18n import ugettext as _
 
 from tracim.lib.base import logger
 from tracim.model import User
 
+from tracim.tracim.lib.utils import get_rq_queue
+
 
 def send_email_through(
         send_callable: typing.Callable[[Message], None],
     if cfg.EMAIL_PROCESSING_MODE == CFG.CST.SYNC:
         send_callable(message)
     elif cfg.EMAIL_PROCESSING_MODE == CFG.CST.ASYNC:
-        queue = Queue('mail_sender', connection=Redis(
-            host=cfg.EMAIL_SENDER_REDIS_HOST,
-            port=cfg.EMAIL_SENDER_REDIS_PORT,
-            db=cfg.EMAIL_SENDER_REDIS_DB,
-        ))
+        queue = get_rq_queue('mail_sender')
         queue.enqueue(send_callable, message)
     else:
         raise NotImplementedError(

tracim/tracim/lib/system.py

+# -*- coding: utf-8 -*-
+import os
+import signal
+
+from tracim.lib.daemons import DaemonsManager
+
+
+class InterruptManager(object):
+    def __init__(self, daemons_manager: DaemonsManager):
+        self.daemons_manager = daemons_manager
+        self.process_pid = os.getpid()
+        self._install_sgnal_handlers()
+
+    def _install_sgnal_handlers(self) -> None:
+        """
+        Install signal handler to intercept SIGINT and SIGTERM signals
+        """
+        signal.signal(signal.SIGTERM, self.stop)
+        signal.signal(signal.SIGINT, self.stop)
+
+    def _remove_signal_handlers(self) -> None:
+        """
+        Remove installed signals to permit stop of main thread.
+        """
+        signal.signal(signal.SIGTERM, signal.SIG_DFL)
+        signal.signal(signal.SIGINT, signal.SIG_DFL)
+
+    def stop(self, signum, frame) -> None:
+        """
+        Run stopping process needed when tracim have to stop.
+        :param signum: signal interruption value
+        :param frame: frame of signal origin
+        """
+        self._remove_signal_handlers()
+        self.daemons_manager.stop_all()
+        # Web server is managed by end of stack like uwsgi, apache2.
+        # So to ask it's termination, we have to use standard kills signals
+        os.kill(self.process_pid, signum)

tracim/tracim/lib/utils.py

 from tg.support.registry import StackedObjectProxy
 from tg.util import LazyString as BaseLazyString
 from tg.util import lazify
+from redis import Redis
+from rq import Queue
 
 from tracim.lib.base import logger
 from webob import Response
     raise NotImplementedError()
 
 
-def add_signal_handler(signal_id, handler) -> None:
-    """
-    Add a callback attached to python signal.
-    :param signal_id: signal identifier (eg. signal.SIGTERM)
-    :param handler: callback to execute when signal trig
-    """
-    def _handler(*args, **kwargs):
-        handler()
-        signal.signal(signal_id, signal.SIG_DFL)
-        os.kill(os.getpid(), signal_id)  # Rethrow signal
-
-    signal.signal(signal_id, _handler)
-
-
 class APIWSGIHTTPException(WSGIHTTPException):
     def json_formatter(self, body, status, title, environ):
         if self.comment:
         return text
 
 lazy_ugettext = lazify(_lazy_ugettext)
+
+
+def get_rq_queue(queue_name: str= 'default') -> Queue:
+    """
+    :param queue_name: name of queue
+    :return: wanted queue
+    """
+    from tracim.config.app_cfg import CFG
+    cfg = CFG.get_instance()
+
+    return Queue(queue_name, connection=Redis(
+        host=cfg.EMAIL_SENDER_REDIS_HOST,
+        port=cfg.EMAIL_SENDER_REDIS_PORT,
+        db=cfg.EMAIL_SENDER_REDIS_DB,
+    ))