fuel snapshot hangs

[Alexander Gubanov]

Detailed bug description:

I have faced with issue on MOS QA CI - generating Dignostic Snapshot hangs

/var/log from failed job available here
https://bugs.launchpad.net/fuel/+bug/1604311/+attachment/4724962/+files/var.log.tar.gz

MOS 9.x, snapshot #157, fuel-qa stable/mitaka
snapshot repo details: http://pastebin.com/Mx3b1bNs

Here is similar issue https://bugs.launchpad.net/fuel/+bug/1604311

Steps to reproduce:
  - install cluster by dos.py
  - run 'fuel snapshot'
Expected results:
  - execution finished with no errors
  - snapshot created in /var/dump/
Actual result:
  - execution hangs

  According to Shotgun logs the snapshot was successfully generated. The "hang" effect was caused by different thing.

2016-08-21 01:10:21.087 ERROR [7f48871f9740] (receiverd) Message consume failed: <kombu.transport.pyamqp.Message object at 0x37c60e8>
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/nailgun/rpc/receiverd.py", line 54, in consume_msg
    callback(**body["args"])
  File "/usr/lib/python2.7/site-packages/nailgun/rpc/receiver.py", line 1180, in dump_environment_resp
    kwargs={'snapshot_name': dumpfile})
  File "/usr/lib/python2.7/site-packages/nailgun/utils/__init__.py", line 41, in reverse
    """This convenience function improves readability of the code like this:
  File "/usr/lib/python2.7/site-packages/nailgun/api/v1/urls.py", line 90, in <module>
    from nailgun.api.v1.handlers.plugin import PluginCollectionHandler
  File "/usr/lib/python2.7/site-packages/nailgun/api/v1/handlers/plugin.py", line 25, in <module>
    from nailgun.api.v1.validators import plugin
  File "/usr/lib/python2.7/site-packages/nailgun/api/v1/validators/plugin.py", line 20, in <module>
    from nailgun.objects import ClusterPlugin
ImportError: cannot import name ClusterPlugin

[Georgy Kibardin (gkibardin)]

removing pyc files and restarting nailgun and receiverd fixes the problem.