dnscelery: fix hostname handling

dnscelery.py

 from os import getenv, path
+from argparse import ArgumentParser
 import subprocess
 
 from kombu import Queue, Exchange
-from socket import gethostname
 from celery import Celery
 
 
-HOSTNAME = gethostname()
+parser = ArgumentParser()
+parser.add_argument('-n', '--hostname', dest='hostname',
+                    help='Define the full queue name with'
+                    'with priority', metavar='hostname.queue')
+(args, unknwon_args) = parser.parse_known_args()
+HOSTNAME = vars(args).pop('hostname')
+if HOSTNAME is None:
+    raise Exception('You must define hostname as -n <hostname> or '
+                    '--hostname=<hostname>.\n'
+                    'Hostname format must be hostname.queue.')
+
+
 AMQP_URI = getenv('AMQP_URI')
 DNS_DB_DIR = getenv('DNS_DB_DIR', '/var/lib/circle/dnsdriver')
 
@@ -15,7 +26,7 @@ celery.conf.update(
     CELERY_RESULT_BACKEND='amqp',
     CELERY_TASK_RESULT_EXPIRES=300,
     CELERY_QUEUES=(
-        Queue(HOSTNAME + '.dns', Exchange(
+        Queue(HOSTNAME, Exchange(
               'dnsdriver', type='direct'), routing_key='dnsdriver'),
     )
 )