[Tutor] unexpected signal behaviour

[dave selby]

Hi all,

I have written a daemon as part of a larger project, if it recieves a
SIGHUP signal it needs to re-read its config file. It works in that I
get 'signal HUP detected, re-reading config file' in syslog but then
the script exits ... mmm .... first time I have used signal catching
... thought it would continue its infinate loop. Any idea anyone ?

Cheers

Dave




import os,  sys, time, signal, ConfigParser, kmotion_logger

class Kmotion_Hkd2:

    def __init__(self):
        self.snap_init = [ 0 for i in xrange(16) ]
        self.snap_count = [ 0 for i in xrange(16) ]
        self.video_dir = ''
        self.motion_feeds = ''
        self.logger = kmotion_logger.Logger('kmotion_hdk2', 'DEBUG')
        signal.signal(signal.SIGHUP, self.signal_hup)
        self.read_config()

    def start_daemon(self):
        self.logger.log('daemon starting ...', 'DEBUG')
        """" Start the house keeping 2 daemon """
        while(True):
            target_date = time.strftime('%Y%m%d')
            # Scan the feeds
            for feed in xrange(self.motion_feeds):
                target_tmp = '%s/%s/%02i/tmp/' % (self.video_dir,
target_date, (feed + 1))
                target_video = '%s/%s/%02i/video/' % (self.video_dir,
target_date, (feed + 1))

                # If target_date or target_tmp don't exist they will
shortly as motion auto generates them
                # If target_video doesn't exist, could be just no
motion so add dir
                if not(os.path.isdir(self.video_dir + '/' +
target_date)) or not(os.path.isdir(target_tmp)): continue
                if not(os.path.isdir(target_video)): os.mkdir(target_video)

                jpeg_list = os.listdir(target_tmp)
                jpeg_list.sort()

                while (len(jpeg_list) >= 3):
                    jpeg = jpeg_list[:1][0]
                    self.snap_count[feed] = self.snap_count[feed] - 1

                    if  self.snap_count[feed]:
                        # Still counting down the snap_count[], so
delete the snapshot
                        self.logger.log('deleteing snapshot %s' %
(target_tmp + jpeg), 'DEBUG')
                        os.remove(target_tmp + jpeg)

                    else:  # snap_count[] = 0, reset it & do something
with the snapshot
                        self.snap_count[feed] = self.snap_init[feed]

                        if os.path.isdir(target_video + jpeg[:-4]) or
not(self.snap_init[feed]):
                            # If there is a video file dir or if
snap_init[feed] = 0, we dont need a snapshot so remove it
                            self.logger.log('remove snapshot due to
video clash %s/tmp/%s' % (self.video_dir, jpeg), 'DEBUG')
                            os.remove(target_tmp + jpeg)

                        else:  # No video file dir, move the snapshot
                            self.logger.log('rename %s %s' %
(target_tmp + jpeg, target_video + jpeg), 'DEBUG')
                            os.rename(target_tmp + jpeg, target_video + jpeg)

                    jpeg_list = jpeg_list[1:]
            time.sleep(2)

    def read_config(self):
        """ Read config file from '~/.kde/share/apps/kmotion/kmotion.rc' """
        parser = ConfigParser.SafeConfigParser()
        parsed =
parser.read(os.path.expanduser('~/.kde/share/apps/kmotion/kmotion.rc'))
        if parsed[0][-10:] != 'kmotion.rc':
            emsg = 'Can\'t open config file %s - killing motion & all
daemon processes' % (parsed[0][-10:])
            self.logger.log(emsg, 'CRIT')
            self.kill_daemons()
            sys.exit()

        try:
            self.video_dir = parser.get('misc', 'video_dir')
            self.motion_feeds = 0  # Get ready to count the live feeds
            for i in xrange(0, 16):
                self.snap_init[i] = int(parser.get('feed%s' %
(str(i)), 'snapshot_interval'))
                if parser.get('feed%s' % (str(i)), 'live') == "yes" :
self.motion_feeds = self.motion_feeds + 1
        except:
            emsg = 'Corrupt config %s - Killing motion & all daemons
processes' %  (sys.exc_info()[1])
            self.logger.log(emsg, 'CRIT')
            self.kill_daemons()
            sys.exit()

        for i in xrange(16):  # Force an immediate snapshot on all feeds
            self.snap_count[i] = 1

    def kill_daemons(self):
        """ Kill motion & all daemons """
        os.system('killall -q motion')
        os.system('pkill -f \'python.+kmotion_hkd1.py\'')

    def signal_hup(self, signum, frame):
            """ Re-read the config file on SIGHUP """
            self.logger.log('signal HUP detected, re-reading config
file', 'DEBUG')
            self.read_config()

if __name__ == '__main__':
    Hkd2 = Kmotion_Hkd2()
    Hkd2.start_daemon()



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