ubuntu binary job fails due to nova-api failure

2017-09-01 17:03:29.454 7 ERROR nova Traceback (most recent call last):
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/bin/nova-api", line 10, in <module>
2017-09-01 17:03:29.454 7 ERROR nova sys.exit(main())
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/cmd/api.py", line 58, in main
2017-09-01 17:03:29.454 7 ERROR nova server = service.WSGIService(api, use_ssl=should_use_ssl)
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/service.py", line 308, in __init__
2017-09-01 17:03:29.454 7 ERROR nova self.manager = self._get_manager()
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/service.py", line 363, in _get_manager
2017-09-01 17:03:29.454 7 ERROR nova return manager_class()
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/api/manager.py", line 30, in __init__
2017-09-01 17:03:29.454 7 ERROR nova self.network_driver.metadata_accept()
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/network/linux_net.py", line 606, in metadata_accept
2017-09-01 17:03:29.454 7 ERROR nova iptables_manager.apply()
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/network/linux_net.py", line 346, in apply
2017-09-01 17:03:29.454 7 ERROR nova self._apply()
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/oslo_concurrency/lockutils.py", line 274, in inner
2017-09-01 17:03:29.454 7 ERROR nova return f(*args, **kwargs)
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/network/linux_net.py", line 366, in _apply
2017-09-01 17:03:29.454 7 ERROR nova attempts=5)
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/network/linux_net.py", line 1167, in _execute
2017-09-01 17:03:29.454 7 ERROR nova return utils.execute(*cmd, **kwargs)
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/utils.py", line 289, in execute
2017-09-01 17:03:29.454 7 ERROR nova return RootwrapProcessHelper().execute(*cmd, **kwargs)
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/utils.py", line 172, in execute
2017-09-01 17:03:29.454 7 ERROR nova return processutils.execute(*cmd, **kwargs)
2017-09-01 17:03:29.454 7 ERROR nova File "/usr/lib/python2.7/dist-packages/oslo_concurrency/processutils.py", line 400, in execute
2017-09-01 17:03:29.454 7 ERROR nova cmd=sanitized_cmd)
2017-09-01 17:03:29.454 7 ERROR nova ProcessExecutionError: Unexpected error while running command.
2017-09-01 17:03:29.454 7 ERROR nova Command: sudo nova-rootwrap /etc/nova/rootwrap.conf iptables-save -c
2017-09-01 17:03:29.454 7 ERROR nova Exit code: 1
2017-09-01 17:03:29.454 7 ERROR nova Stdout: u''
2017-09-01 17:03:29.454 7 ERROR nova Stderr: u'iptables-save v1.6.0: Cannot initialize: Permission denied (you must be root)\n\n'
2017-09-01 17:03:29.454 7 ERROR nova

This patch is related to https://review.openstack.org/#/c/488527/