openstack-nova in OSP 7 requires python-oslo-rootwrap.  After upgrading from OSP 6, the nova-api service will fail with:

CRITICAL nova [-] ProcessExecutionError: Unexpected error while running command.
Command: sudo nova-rootwrap /etc/nova/rootwrap.conf iptables-save -c
Exit code: 1
Stdout: u''
Stderr: u'Traceback (most recent call last):\n  File "/usr/bin/nova-rootwrap", line 6, in <module>\n    from oslo_rootwrap
.cmd import main\nImportError: No module named oslo_rootwrap.cmd\n'
TRACE nova Traceback (most recent call last):
TRACE nova   File "/usr/bin/nova-api", line 10, in <module>
TRACE nova     sys.exit(main())
TRACE nova   File "/usr/lib/python2.7/site-packages/nova/cmd/api.py", line 55, in main
TRACE nova     server = service.WSGIService(api, use_ssl=should_use_ssl)
TRACE nova   File "/usr/lib/python2.7/site-packages/nova/service.py", line 333, in __init__
TRACE nova     self.manager = self._get_manager()
TRACE nova   File "/usr/lib/python2.7/site-packages/nova/service.py", line 390, in _get_manager
TRACE nova     return manager_class()
TRACE nova   File "/usr/lib/python2.7/site-packages/nova/api/manager.py", line 30, in __init__
TRACE nova     self.network_driver.metadata_accept()
TRACE nova   File "/usr/lib/python2.7/site-packages/nova/network/linux_net.py", line 700, in metadata_accept
TRACE nova     iptables_manager.apply()
TRACE nova   File "/usr/lib/python2.7/site-packages/nova/network/linux_net.py", line 442, in apply
TRACE nova     self._apply()
TRACE nova   File "/usr/lib/python2.7/site-packages/oslo_concurrency/lockutils.py", line 445, in inner
TRACE nova     return f(*args, **kwargs)
TRACE nova   File "/usr/lib/python2.7/site-packages/nova/network/linux_net.py", line 462, in _apply
TRACE nova     attempts=5)
TRACE nova   File "/usr/lib/python2.7/site-packages/nova/network/linux_net.py", line 1266, in _execute
TRACE nova     return utils.execute(*cmd, **kwargs)
TRACE nova   File "/usr/lib/python2.7/site-packages/nova/utils.py", line 213, in execute
TRACE nova     return processutils.execute(*cmd, **kwargs)
TRACE nova   File "/usr/lib/python2.7/site-packages/oslo_concurrency/processutils.py", line 233, in execute
TRACE nova     cmd=sanitized_cmd)
TRACE nova ProcessExecutionError: Unexpected error while running command.
TRACE nova Command: sudo nova-rootwrap /etc/nova/rootwrap.conf iptables-save -c
TRACE nova Exit code: 1
TRACE nova Stdout: u''
TRACE nova Stderr: u'Traceback (most recent call last):\n  File "/usr/bin/nova-rootwrap", line 6, in <module>\n    from oslo_rootwrap.cmd import main\nImportError: No module named oslo_rootwrap.cmd\n'

In version:

openstack-nova-api-2015.1.0-16.el7ost.noarch