Convert libvirt's RBD storage to using processutils.execute()

Nova's utils.execute() is just a redirector now and should go
away, so I am progressively moving things over to calling
processutils directly.

Change-Id: I745b3433a447aeec819781e0ee26df6e6c70530a
blueprint: execs-ive-had-a-few

nova/tests/unit/virt/libvirt/storage/test_rbd.py

@@ -19,7 +19,6 @@ from nova import exception
 from nova import objects
 from nova import test
 from nova.tests import uuidsentinel as uuids
-from nova import utils
 from nova.virt.libvirt.storage import rbd_utils
 from nova.virt.libvirt import utils as libvirt_utils
 
@@ -173,7 +172,7 @@ class RbdTestCase(test.NoDBTestCase):
             self.driver.is_cloneable(location, image_meta))
         self.assertTrue(mock_get_fsid.called)
 
-    @mock.patch.object(utils, 'execute')
+    @mock.patch('oslo_concurrency.processutils.execute')
     def test_get_mon_addrs(self, mock_execute):
         mock_execute.return_value = (CEPH_MON_DUMP, '')
         hosts = ['::1', '::1', '::1', '127.0.0.1', 'example.com']

nova/virt/libvirt/storage/rbd_utils.py

@@ -24,6 +24,7 @@ except ImportError:
     rados = None
     rbd = None
 
+from oslo_concurrency import processutils
 from oslo_log import log as logging
 from oslo_serialization import jsonutils
 from oslo_service import loopingcall
@@ -32,7 +33,6 @@ from oslo_utils import units
 
 from nova import exception
 from nova.i18n import _
-from nova import utils
 from nova.virt.libvirt import utils as libvirt_utils
 
 LOG = logging.getLogger(__name__)
@@ -162,7 +162,7 @@ class RBDDriver(object):
 
     def get_mon_addrs(self):
         args = ['ceph', 'mon', 'dump', '--format=json'] + self.ceph_args()
-        out, _ = utils.execute(*args)
+        out, _ = processutils.execute(*args)
         lines = out.split('\n')
         if lines[0].startswith('dumped monmap epoch'):
             lines = lines[1:]
@@ -326,7 +326,7 @@ class RBDDriver(object):
         # we need to use it explicitly.
         args += ['--image-format=2']
         args += self.ceph_args()
-        utils.execute('rbd', 'import', *args)
+        processutils.execute('rbd', 'import', *args)
 
     def _destroy_volume(self, client, volume, pool=None):
         """Destroy an RBD volume, retrying as needed.