tumblesle-release does not send out notification if notification connection died previously

[okurz]

observation

[…]
DEBUG:openqa_review.tumblesle_release:Release DONE
ERROR:pika.adapters.base_connection:Socket Error: 104
WARNING:pika.adapters.base_connection:Socket closed when connection was open
WARNING:pika.connection:Disconnected from RabbitMQ at kazhua.suse.de:5672 (0): Not specified
Traceback (most recent call last):
  File "/home/tumblesle/venv/bin/tumblesle-release", line 9, in <module>
    load_entry_point('openqa-review===1.4.1-9-g73059a2', 'console_scripts', 'tumblesle-release')()
  File "/home/tumblesle/venv/lib/python2.7/site-packages/openqa_review/tumblesle_release.py", line 395, in main
    tr.run()
  File "/home/tumblesle/venv/lib/python2.7/site-packages/openqa_review/tumblesle_release.py", line 145, in run
    self.one_run()
  File "/home/tumblesle/venv/lib/python2.7/site-packages/openqa_review/tumblesle_release.py", line 156, in one_run
    self.release()
  File "/home/tumblesle/venv/lib/python2.7/site-packages/openqa_review/tumblesle_release.py", line 318, in release
    self.notify({'build': self.release_build}, topic='release')
  File "/home/tumblesle/venv/lib/python2.7/site-packages/openqa_review/tumblesle_release.py", line 136, in notify
    self.notify_channel.basic_publish(exchange='pubsub', routing_key='.'.join([self.notify_topic, topic]), body=body)
  File "/home/tumblesle/venv/lib/python2.7/site-packages/pika/adapters/blocking_connection.py", line 1978, in basic_publish
    mandatory, immediate)
  File "/home/tumblesle/venv/lib/python2.7/site-packages/pika/adapters/blocking_connection.py", line 2065, in publish
    self._flush_output()
  File "/home/tumblesle/venv/lib/python2.7/site-packages/pika/adapters/blocking_connection.py", line 1174, in _flush_output
    *waiters)
  File "/home/tumblesle/venv/lib/python2.7/site-packages/pika/adapters/blocking_connection.py", line 395, in _flush_output
    raise exceptions.ConnectionClosed()
pika.exceptions.ConnectionClosed
Exception pika.exceptions.ConnectionClosed: The AMQP connection was closed: () in <bound method TumblesleRelease.__del__ of <openqa_review.tumblesle_release.TumblesleRelease object at 0x7f1cae6fb110>> ignored

steps to reproduce

I assume we could do the following

• start test server
• let tumblesle-release connect to server initially
• terminate notification server
• let tumblesle-release run into the notification and see it fail or wait until the second time and it still fails although the server might be up again

suggestion

-        self.notify_channel.exchange_declare(exchange='pubsub', type='topic')
+        self.notify_channel.exchange_declare(exchange='pubsub', type='topic', passive=True, durable=True)