Backslash continuation removal (Nova folsom-2)

Fixes bug #938588

Backslash continuations removal for scripts in bin/, plugin/, and etc.

Change-Id: Idd17048b6e8db6e939946968e011e68da8585b8d

26 files changed, 219 insertions, 222 deletions

diff --git a/HACKING.rst b/HACKING.rst
index a28bc37432..c85f5f3055 100644
--- a/HACKING.rst
+++ b/HACKING.rst
@@ -10,6 +10,8 @@ General
 -------
 - Put two newlines between top-level code (funcs, classes, etc)
 - Put one newline between methods in classes and anywhere else
+- Long lines should be wrapped in parentheses
+  in preference to using a backslash for line continuation.
 - Do not write "except:", use "except Exception:" at the very least
 - Include your name with TODOs as in "#TODO(termie)"
 - Do not shadow a built-in or reserved word. Example::
diff --git a/bin/clear_rabbit_queues b/bin/clear_rabbit_queues
index 1912046b62..c367c06c62 100755
--- a/bin/clear_rabbit_queues
+++ b/bin/clear_rabbit_queues
@@ -48,10 +48,9 @@ from nova.openstack.common import cfg
 from nova import rpc
 
 
-delete_exchange_opt = \
-    cfg.BoolOpt('delete_exchange',
-                default=False,
-                help='delete nova exchange too.')
+delete_exchange_opt = cfg.BoolOpt('delete_exchange',
+                                  default=False,
+                                  help='delete nova exchange too.')
 
 FLAGS = flags.FLAGS
 FLAGS.register_cli_opt(delete_exchange_opt)
diff --git a/bin/nova-dhcpbridge b/bin/nova-dhcpbridge
index c11947da26..109d7101b5 100755
--- a/bin/nova-dhcpbridge
+++ b/bin/nova-dhcpbridge
@@ -108,10 +108,10 @@ def main():
     if action in ['add', 'del', 'old']:
         mac = argv[2]
         ip = argv[3]
-        msg = _("Called '%(action)s' for mac '%(mac)s' with ip '%(ip)s'") % \
-                    {"action": action,
-                     "mac": mac,
-                     "ip": ip}
+        msg = (_("Called '%(action)s' for mac '%(mac)s' with ip '%(ip)s'") %
+               {"action": action,
+                "mac": mac,
+                "ip": ip})
         LOG.debug(msg)
         globals()[action + '_lease'](mac, ip)
     else:
diff --git a/bin/nova-manage b/bin/nova-manage
index 1554251a09..2eacffcd07 100755
--- a/bin/nova-manage
+++ b/bin/nova-manage
@@ -593,8 +593,8 @@ class FixedIpCommands(object):
                     hostname = instance['hostname']
                     host = instance['host']
                 else:
-                    print 'WARNING: fixed ip %s allocated to missing' \
-                    ' instance' % str(fixed_ip['address'])
+                    print ('WARNING: fixed ip %s allocated to missing'
+                           ' instance' % str(fixed_ip['address']))
             print "%-18s\t%-15s\t%-15s\t%s" % (
                     network['cidr'],
                     fixed_ip['address'],
@@ -760,8 +760,8 @@ class NetworkCommands(object):
             if FLAGS.network_manager in bridge_required:
                 raise exception.NetworkNotCreated(req='--bridge')
 
-        bridge_interface = bridge_interface or FLAGS.flat_interface or \
-                           FLAGS.vlan_interface
+        bridge_interface = (bridge_interface or FLAGS.flat_interface or
+                            FLAGS.vlan_interface)
         if not bridge_interface:
             interface_required = ['nova.network.manager.VlanManager']
             if FLAGS.network_manager in interface_required:
@@ -873,8 +873,8 @@ class NetworkCommands(object):
             if uuid is None:
                 raise Exception("UUID is required to delete Quantum Networks")
             if fixed_range:
-                raise Exception("Deleting by fixed_range is not supported " \
-                    "with the QuantumManager")
+                raise Exception("Deleting by fixed_range is not supported "
+                                "with the QuantumManager")
         # delete the network
         net_manager.delete_network(context.get_admin_context(),
             fixed_range, uuid)
@@ -920,20 +920,19 @@ class VmCommands(object):
     def list(self, host=None):
         """Show a list of all instances"""
 
-        print "%-10s %-15s %-10s %-10s %-26s %-9s %-9s %-9s" \
-              "  %-10s %-10s %-10s %-5s" % (
-            _('instance'),
-            _('node'),
-            _('type'),
-            _('state'),
-            _('launched'),
-            _('image'),
-            _('kernel'),
-            _('ramdisk'),
-            _('project'),
-            _('user'),
-            _('zone'),
-            _('index'))
+        print ("%-10s %-15s %-10s %-10s %-26s %-9s %-9s %-9s"
+               "  %-10s %-10s %-10s %-5s" % (_('instance'),
+                                             _('node'),
+                                             _('type'),
+                                             _('state'),
+                                             _('launched'),
+                                             _('image'),
+                                             _('kernel'),
+                                             _('ramdisk'),
+                                             _('project'),
+                                             _('user'),
+                                             _('zone'),
+                                             _('index')))
 
         if host is None:
             instances = db.instance_get_all(context.get_admin_context())
@@ -942,20 +941,19 @@ class VmCommands(object):
                            context.get_admin_context(), host)
 
         for instance in instances:
-            print "%-10s %-15s %-10s %-10s %-26s %-9s %-9s %-9s" \
-                  "  %-10s %-10s %-10s %-5d" % (
-                instance['display_name'],
-                instance['host'],
-                instance['instance_type'].name,
-                instance['vm_state'],
-                instance['launched_at'],
-                instance['image_ref'],
-                instance['kernel_id'],
-                instance['ramdisk_id'],
-                instance['project_id'],
-                instance['user_id'],
-                instance['availability_zone'],
-                instance['launch_index'])
+            print ("%-10s %-15s %-10s %-10s %-26s %-9s %-9s %-9s"
+                   " %-10s %-10s %-10s %-5d" % (instance['display_name'],
+                                                instance['host'],
+                                                instance['instance_type'].name,
+                                                instance['vm_state'],
+                                                instance['launched_at'],
+                                                instance['image_ref'],
+                                                instance['kernel_id'],
+                                                instance['ramdisk_id'],
+                                                instance['project_id'],
+                                                instance['user_id'],
+                                                instance['availability_zone'],
+                                                instance['launch_index']))
 
 
 class ServiceCommands(object):
@@ -1040,17 +1038,17 @@ class ServiceCommands(object):
                                                          "c": _('cpu'),
                                                          "d": _('mem(mb)'),
                                                          "e": _('hdd')}
-            print '%(a)-16s(total)%(b)26s%(c)8s%(d)8s' %\
-                              {"a": host,
-                               "b": result['resource']['vcpus'],
-                               "c": result['resource']['memory_mb'],
-                               "d": result['resource']['local_gb']}
-
-            print '%(a)-16s(used_now)%(b)23s%(c)8s%(d)8s' %\
-                              {"a": host,
-                               "b": result['resource']['vcpus_used'],
-                               "c": result['resource']['memory_mb_used'],
-                               "d": result['resource']['local_gb_used']}
+            print ('%(a)-16s(total)%(b)26s%(c)8s%(d)8s' %
+                   {"a": host,
+                    "b": result['resource']['vcpus'],
+                    "c": result['resource']['memory_mb'],
+                    "d": result['resource']['local_gb']})
+
+            print ('%(a)-16s(used_now)%(b)23s%(c)8s%(d)8s' %
+                   {"a": host,
+                    "b": result['resource']['vcpus_used'],
+                    "c": result['resource']['memory_mb_used'],
+                    "d": result['resource']['local_gb_used']})
 
             # Printing a used_max
             cpu_sum = 0
@@ -1121,9 +1119,9 @@ class VersionCommands(object):
         pass
 
     def list(self):
-        print _("%(version)s (%(vcs)s)") % \
-                {'version': version.version_string(),
-                 'vcs': version.version_string_with_vcs()}
+        print (_("%(version)s (%(vcs)s)") %
+               {'version': version.version_string(),
+                'vcs': version.version_string_with_vcs()})
 
     def __call__(self):
         self.list()
@@ -1689,9 +1687,9 @@ def main():
 
     script_name = argv.pop(0)
     if len(argv) < 1:
-        print _("\nOpenStack Nova version: %(version)s (%(vcs)s)\n") % \
-                {'version': version.version_string(),
-                 'vcs': version.version_string_with_vcs()}
+        print (_("\nOpenStack Nova version: %(version)s (%(vcs)s)\n") %
+               {'version': version.version_string(),
+                'vcs': version.version_string_with_vcs()})
         print script_name + " category action [<args>]"
         print _("Available categories:")
         for k, _v in CATEGORIES:
diff --git a/nova/api/openstack/compute/contrib/extended_server_attributes.py b/nova/api/openstack/compute/contrib/extended_server_attributes.py
index 2da5badc34..4c584ec057 100644
--- a/nova/api/openstack/compute/contrib/extended_server_attributes.py
+++ b/nova/api/openstack/compute/contrib/extended_server_attributes.py
@@ -104,8 +104,8 @@ class Extended_server_attributes(extensions.ExtensionDescriptor):
 
     name = "ExtendedServerAttributes"
     alias = "OS-EXT-SRV-ATTR"
-    namespace = "http://docs.openstack.org/compute/ext/" \
-                "extended_status/api/v1.1"
+    namespace = ("http://docs.openstack.org/compute/ext/"
+                 "extended_status/api/v1.1")
     updated = "2011-11-03T00:00:00+00:00"
 
     def get_controller_extensions(self):
@@ -125,9 +125,9 @@ class ExtendedServerAttributeTemplate(xmlutil.TemplateBuilder):
     def construct(self):
         root = xmlutil.TemplateElement('server', selector='server')
         make_server(root)
-        return xmlutil.SlaveTemplate(root, 1, nsmap={
-            Extended_server_attributes.alias: \
-            Extended_server_attributes.namespace})
+        alias = Extended_server_attributes.alias
+        namespace = Extended_server_attributes.namespace
+        return xmlutil.SlaveTemplate(root, 1, nsmap={alias: namespace})
 
 
 class ExtendedServerAttributesTemplate(xmlutil.TemplateBuilder):
@@ -135,6 +135,6 @@ class ExtendedServerAttributesTemplate(xmlutil.TemplateBuilder):
         root = xmlutil.TemplateElement('servers')
         elem = xmlutil.SubTemplateElement(root, 'server', selector='servers')
         make_server(elem)
-        return xmlutil.SlaveTemplate(root, 1, nsmap={
-            Extended_server_attributes.alias: \
-            Extended_server_attributes.namespace})
+        alias = Extended_server_attributes.alias
+        namespace = Extended_server_attributes.namespace
+        return xmlutil.SlaveTemplate(root, 1, nsmap={alias: namespace})
diff --git a/nova/api/openstack/compute/contrib/flavorextradata.py b/nova/api/openstack/compute/contrib/flavorextradata.py
index 9a07270ce4..2864ada5e5 100644
--- a/nova/api/openstack/compute/contrib/flavorextradata.py
+++ b/nova/api/openstack/compute/contrib/flavorextradata.py
@@ -55,8 +55,7 @@ class FlavorextradataController(wsgi.Controller):
             resp_obj.attach(xml=FlavorextradatumTemplate())
 
             try:
-                flavor_ref = instance_types.\
-                                get_instance_type_by_flavor_id(id)
+                flavor_ref = instance_types.get_instance_type_by_flavor_id(id)
             except exception.FlavorNotFound:
                 explanation = _("Flavor not found.")
                 raise exception.HTTPNotFound(explanation=explanation)
@@ -118,8 +117,9 @@ class FlavorextradatumTemplate(xmlutil.TemplateBuilder):
     def construct(self):
         root = xmlutil.TemplateElement('flavor', selector='flavor')
         make_flavor(root)
-        return xmlutil.SlaveTemplate(root, 1, nsmap={
-            Flavorextradata.alias: Flavorextradata.namespace})
+        alias = Flavorextradata.alias
+        namespace = Flavorextradata.namespace
+        return xmlutil.SlaveTemplate(root, 1, nsmap={alias: namespace})
 
 
 class FlavorextradataTemplate(xmlutil.TemplateBuilder):
@@ -127,5 +127,6 @@ class FlavorextradataTemplate(xmlutil.TemplateBuilder):
         root = xmlutil.TemplateElement('flavors')
         elem = xmlutil.SubTemplateElement(root, 'flavor', selector='flavors')
         make_flavor(elem)
-        return xmlutil.SlaveTemplate(root, 1, nsmap={
-            Flavorextradata.alias: Flavorextradata.namespace})
+        alias = Flavorextradata.alias
+        namespace = Flavorextradata.namespace
+        return xmlutil.SlaveTemplate(root, 1, nsmap={alias: namespace})
diff --git a/nova/network/model.py b/nova/network/model.py
index 84a8ab35e7..e0851ded2a 100644
--- a/nova/network/model.py
+++ b/nova/network/model.py
@@ -344,15 +344,16 @@ class NetworkInfo(list):
             gateway = get_ip(subnet_v4['gateway'])
             dhcp_server = subnet_v4.get_meta('dhcp_server', gateway)
 
-            network_dict = \
-                    {'bridge': network['bridge'],
-                     'id': network['id'],
-                     'cidr': subnet_v4['cidr'],
-                     'cidr_v6': subnet_v6['cidr'] if subnet_v6 else None,
-                     'vlan': network.get_meta('vlan'),
-                     'injected': network.get_meta('injected', False),
-                     'multi_host': network.get_meta('multi_host', False),
-                     'bridge_interface': network.get_meta('bridge_interface')}
+            network_dict = {
+                'bridge': network['bridge'],
+                'id': network['id'],
+                'cidr': subnet_v4['cidr'],
+                'cidr_v6': subnet_v6['cidr'] if subnet_v6 else None,
+                'vlan': network.get_meta('vlan'),
+                'injected': network.get_meta('injected', False),
+                'multi_host': network.get_meta('multi_host', False),
+                'bridge_interface': network.get_meta('bridge_interface')
+            }
             # NOTE(tr3buchet): 'ips' bit here is tricky, we support a single
             #                  subnet but we want all the IPs to be there
             #                  so use the v4_subnets[0] and its IPs are first
diff --git a/nova/network/quantum/manager.py b/nova/network/quantum/manager.py
index 50bc8cf145..689c787fd2 100644
--- a/nova/network/quantum/manager.py
+++ b/nova/network/quantum/manager.py
@@ -283,8 +283,8 @@ class QuantumManager(manager.FloatingIP, manager.FlatManager):
 
         # Now we can delete the network
         self.q_conn.delete_network(q_tenant_id, net_uuid)
-        LOG.debug("Deleting network %s for tenant: %s" % \
-                                    (net_uuid, q_tenant_id))
+        LOG.debug("Deleting network %s for tenant: %s" %
+                  (net_uuid, q_tenant_id))
         self.ipam.delete_subnets_by_net_id(context, net_uuid, project_id)
         # Get rid of dnsmasq
         if FLAGS.quantum_use_dhcp:
diff --git a/nova/notifications.py b/nova/notifications.py
index 4e3d1362dd..b7c320fbee 100644
--- a/nova/notifications.py
+++ b/nova/notifications.py
@@ -68,8 +68,8 @@ def send_update_with_states(context, instance, old_vm_state, new_vm_state,
     if old_vm_state != new_vm_state:
         # yes, the vm state is changing:
         fire_update = True
-    elif FLAGS.notify_on_state_change.lower() == "vm_and_task_state" and \
-         old_task_state != new_task_state:
+    elif (FLAGS.notify_on_state_change.lower() == "vm_and_task_state" and
+          old_task_state != new_task_state):
         # yes, the task state is changing:
         fire_update = True
 
diff --git a/nova/tests/compute/test_compute.py b/nova/tests/compute/test_compute.py
index f1903bd4cd..cdcf0ec8c8 100644
--- a/nova/tests/compute/test_compute.py
+++ b/nova/tests/compute/test_compute.py
@@ -4094,13 +4094,14 @@ class KeypairAPITestCase(BaseTestCase):
         self.keypair_api = compute_api.KeypairAPI()
         self.ctxt = context.RequestContext('fake', 'fake')
         self._keypair_db_call_stubs()
-        self.pub_key = 'ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDLnVkqJu9WVf' \
-                  '/5StU3JCrBR2r1s1j8K1tux+5XeSvdqaM8lMFNorzbY5iyoBbRS56gy' \
-                  '1jmm43QsMPJsrpfUZKcJpRENSe3OxIIwWXRoiapZe78u/a9xKwj0avF' \
-                  'YMcws9Rk9iAB7W4K1nEJbyCPl5lRBoyqeHBqrnnuXWEgGxJCK0Ah6wc' \
-                  'OzwlEiVjdf4kxzXrwPHyi7Ea1qvnNXTziF8yYmUlH4C8UXfpTQckwSw' \
-                  'pDyxZUc63P8q+vPbs3Q2kw+/7vvkCKHJAXVI+oCiyMMfffoTq16M1xf' \
-                  'V58JstgtTqAXG+ZFpicGajREUE/E3hO5MGgcHmyzIrWHKpe1n3oEGuz'
+        self.pub_key = ('ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDLnVkqJu9WVf'
+                        '/5StU3JCrBR2r1s1j8K1tux+5XeSvdqaM8lMFNorzbY5iyoBbR'
+                        'S56gy1jmm43QsMPJsrpfUZKcJpRENSe3OxIIwWXRoiapZe78u/'
+                        'a9xKwj0avFYMcws9Rk9iAB7W4K1nEJbyCPl5lRBoyqeHBqrnnu'
+                        'XWEgGxJCK0Ah6wcOzwlEiVjdf4kxzXrwPHyi7Ea1qvnNXTziF8'
+                        'yYmUlH4C8UXfpTQckwSwpDyxZUc63P8q+vPbs3Q2kw+/7vvkCK'
+                        'HJAXVI+oCiyMMfffoTq16M1xfV58JstgtTqAXG+ZFpicGajREU'
+                        'E/E3hO5MGgcHmyzIrWHKpe1n3oEGuz')
         self.fingerprint = '4e:48:c6:a0:4a:f9:dd:b5:4c:85:54:5a:af:43:47:5a'
 
     def _keypair_db_call_stubs(self):
diff --git a/nova/tests/test_volume.py b/nova/tests/test_volume.py
index 2909b51f70..20ac495c92 100644
--- a/nova/tests/test_volume.py
+++ b/nova/tests/test_volume.py
@@ -128,8 +128,8 @@ class VolumeTestCase(test.TestCase):
         self.volume.create_volume(self.context, volume_id)
 
         self.mox.StubOutWithMock(self.volume.driver, 'delete_volume')
-        self.volume.driver.delete_volume(mox.IgnoreArg()) \
-                                              .AndRaise(exception.VolumeIsBusy)
+        self.volume.driver.delete_volume(mox.IgnoreArg()).AndRaise(
+                exception.VolumeIsBusy)
         self.mox.ReplayAll()
         res = self.volume.delete_volume(self.context, volume_id)
         self.assertEqual(True, res)
@@ -374,8 +374,8 @@ class VolumeTestCase(test.TestCase):
         self.volume.create_snapshot(self.context, volume_id, snapshot_id)
 
         self.mox.StubOutWithMock(self.volume.driver, 'delete_snapshot')
-        self.volume.driver.delete_snapshot(mox.IgnoreArg()) \
-                                            .AndRaise(exception.SnapshotIsBusy)
+        self.volume.driver.delete_snapshot(mox.IgnoreArg()).AndRaise(
+                exception.SnapshotIsBusy)
         self.mox.ReplayAll()
         self.volume.delete_snapshot(self.context, snapshot_id)
         snapshot_ref = db.snapshot_get(self.context, snapshot_id)
diff --git a/nova/virt/disk/api.py b/nova/virt/disk/api.py
index 09ede2d50c..5978399db9 100644
--- a/nova/virt/disk/api.py
+++ b/nova/virt/disk/api.py
@@ -129,9 +129,8 @@ def bind(src, target, instance_name):
         s = os.stat(src)
         cgroup_info = "b %s:%s rwm\n" % (os.major(s.st_rdev),
                                          os.minor(s.st_rdev))
-        cgroups_path = \
-            "/sys/fs/cgroup/devices/libvirt/lxc/%s/devices.allow" \
-            % instance_name
+        cgroups_path = ("/sys/fs/cgroup/devices/libvirt/lxc/"
+                        "%s/devices.allow" % instance_name)
         utils.execute('tee', cgroups_path,
                       process_input=cgroup_info, run_as_root=True)
 
diff --git a/nova/virt/libvirt/config.py b/nova/virt/libvirt/config.py
index 2ccfd35fb9..3f068fa053 100644
--- a/nova/virt/libvirt/config.py
+++ b/nova/virt/libvirt/config.py
@@ -95,9 +95,9 @@ class LibvirtConfigGuestDisk(LibvirtConfigGuestDevice):
 
         dev.set("type", self.source_type)
         dev.set("device", self.source_device)
-        if self.driver_name is not None or \
-                self.driver_format is not None or \
-                self.driver_cache is not None:
+        if (self.driver_name is not None or
+            self.driver_format is not None or
+            self.driver_cache is not None):
             drv = etree.Element("driver")
             if self.driver_name is not None:
                 drv.set("name", self.driver_name)
diff --git a/nova/virt/libvirt/connection.py b/nova/virt/libvirt/connection.py
index 8a24c4e55a..ab32ff927d 100644
--- a/nova/virt/libvirt/connection.py
+++ b/nova/virt/libvirt/connection.py
@@ -1760,8 +1760,8 @@ class LibvirtConnection(driver.ComputeDriver):
             return []
 
         return filter(bool,
-                      [target.get("dev") \
-                           for target in doc.findall('devices/disk/target')])
+                      [target.get("dev")
+                       for target in doc.findall('devices/disk/target')])
 
     def get_interfaces(self, instance_name):
         """
diff --git a/nova/virt/xenapi/host.py b/nova/virt/xenapi/host.py
index d5f5683601..a6fb4a92e0 100644
--- a/nova/virt/xenapi/host.py
+++ b/nova/virt/xenapi/host.py
@@ -50,66 +50,65 @@ class Host(object):
     def host_maintenance_mode(self, host, mode):
         """Start/Stop host maintenance window. On start, it triggers
         guest VMs evacuation."""
-        if mode:
-            host_list = [host_ref for host_ref in
-                         self._session.call_xenapi('host.get_all') \
-                         if host_ref != self._session.get_xenapi_host()]
-            migrations_counter = vm_counter = 0
-            ctxt = context.get_admin_context()
-            for vm_ref, vm_rec in vm_utils.VMHelper.list_vms(self._session):
-                for host_ref in host_list:
-                    try:
-                        # Ensure only guest instances are migrated
-                        uuid = vm_rec['other_config'].get('nova_uuid')
+        if not mode:
+            return 'off_maintenance'
+        host_list = [host_ref for host_ref in
+                     self._session.call_xenapi('host.get_all')
+                     if host_ref != self._session.get_xenapi_host()]
+        migrations_counter = vm_counter = 0
+        ctxt = context.get_admin_context()
+        for vm_ref, vm_rec in vm_utils.VMHelper.list_vms(self._session):
+            for host_ref in host_list:
+                try:
+                    # Ensure only guest instances are migrated
+                    uuid = vm_rec['other_config'].get('nova_uuid')
+                    if not uuid:
+                        name = vm_rec['name_label']
+                        uuid = _uuid_find(ctxt, host, name)
                         if not uuid:
-                            name = vm_rec['name_label']
-                            uuid = _uuid_find(ctxt, host, name)
-                            if not uuid:
-                                msg = _('Instance %(name)s running on %(host)s'
-                                        ' could not be found in the database:'
-                                        ' assuming it is a worker VM and skip'
-                                        'ping migration to a new host')
-                                LOG.info(msg % locals())
-                                continue
-                        instance = db.instance_get_by_uuid(ctxt, uuid)
-                        vm_counter = vm_counter + 1
-
-                        dest = _host_find(ctxt, self._session, host, host_ref)
-                        (old_ref, new_ref) = \
-                                db.instance_update_and_get_original(ctxt,
-                                        instance.id,
-                                        {'host': dest,
-                                         'vm_state': vm_states.MIGRATING})
-                        notifications.send_update(ctxt, old_ref, new_ref)
-
-                        self._session.call_xenapi('VM.pool_migrate',
-                                                  vm_ref, host_ref, {})
-                        migrations_counter = migrations_counter + 1
-
-                        (old_ref, new_ref) = \
-                            db.instance_update_and_get_original(ctxt,
-                                    instance.id,
-                                    {'vm_state': vm_states.ACTIVE})
-                        notifications.send_update(ctxt, old_ref, new_ref)
-
-                        break
-                    except self.XenAPI.Failure:
-                        LOG.exception('Unable to migrate VM %(vm_ref)s'
-                                      'from %(host)s' % locals())
-                        (old_ref, new_ref) = \
-                            db.instance_update_and_get_original(ctxt,
+                            msg = _('Instance %(name)s running on %(host)s'
+                                    ' could not be found in the database:'
+                                    ' assuming it is a worker VM and skip'
+                                    ' ping migration to a new host')
+                            LOG.info(msg % locals())
+                            continue
+                    instance = db.instance_get_by_uuid(ctxt, uuid)
+                    vm_counter = vm_counter + 1
+
+                    dest = _host_find(ctxt, self._session, host, host_ref)
+                    (old_ref, new_ref) = db.instance_update_and_get_original(
+                                    ctxt,
                                     instance.id,
-                                    {'hosts': host,
-                                     'vm_state': vm_states.ACTIVE})
-                        notifications.send_update(ctxt, old_ref, new_ref)
-
-            if vm_counter == migrations_counter:
-                return 'on_maintenance'
-            else:
-                raise exception.NoValidHost(reason='Unable to find suitable '
-                                                   'host for VMs evacuation')
+                                    {'host': dest,
+                                     'vm_state': vm_states.MIGRATING})
+                    notifications.send_update(ctxt, old_ref, new_ref)
+
+                    self._session.call_xenapi('VM.pool_migrate',
+                                              vm_ref, host_ref, {})
+                    migrations_counter = migrations_counter + 1
+
+                    (old_ref, new_ref) = db.instance_update_and_get_original(
+                                ctxt,
+                                instance.id,
+                                {'vm_state': vm_states.ACTIVE})
+                    notifications.send_update(ctxt, old_ref, new_ref)
+
+                    break
+                except self.XenAPI.Failure:
+                    LOG.exception('Unable to migrate VM %(vm_ref)s'
+                                  'from %(host)s' % locals())
+                    (old_ref, new_ref) = db.instance_update_and_get_original(
+                                ctxt,
+                                instance.id,
+                                {'hosts': host,
+                                 'vm_state': vm_states.ACTIVE})
+                    notifications.send_update(ctxt, old_ref, new_ref)
+
+        if vm_counter == migrations_counter:
+            return 'on_maintenance'
         else:
-            return 'off_maintenance'
+            raise exception.NoValidHost(reason='Unable to find suitable '
+                                                   'host for VMs evacuation')
 
     def set_host_enabled(self, _host, enabled):
         """Sets the specified host's ability to accept new instances."""
diff --git a/nova/virt/xenapi/vif.py b/nova/virt/xenapi/vif.py
index 905cbc30cd..05bbc33c11 100644
--- a/nova/virt/xenapi/vif.py
+++ b/nova/virt/xenapi/vif.py
@@ -76,8 +76,8 @@ class XenAPIBridgeDriver(XenVIFDriver):
 
         vlan_num = network.get_meta('vlan')
         bridge = network['bridge']
-        bridge_interface = FLAGS.vlan_interface or \
-                           network.get_meta('bridge_interface')
+        bridge_interface = (FLAGS.vlan_interface or
+                            network.get_meta('bridge_interface'))
         # Check whether bridge already exists
         # Retrieve network whose name_label is "bridge"
         network_ref = network_utils.NetworkHelper.find_network_with_name_label(
diff --git a/nova/virt/xenapi/vmops.py b/nova/virt/xenapi/vmops.py
index 8ede499832..c2f2d3b4a3 100644
--- a/nova/virt/xenapi/vmops.py
+++ b/nova/virt/xenapi/vmops.py
@@ -1433,8 +1433,8 @@ class VMOps(object):
 
         for vif in network_info:
             xs_data = self._vif_xenstore_data(vif)
-            location = \
-                    'vm-data/networking/%s' % vif['address'].replace(':', '')
+            location = ('vm-data/networking/%s' %
+                        vif['address'].replace(':', ''))
             self._add_to_param_xenstore(vm_ref, location, json.dumps(xs_data))
             try:
                 self._write_to_xenstore(instance, location, xs_data,
diff --git a/plugins/xenserver/networking/etc/xensource/scripts/ovs_configure_base_flows.py b/plugins/xenserver/networking/etc/xensource/scripts/ovs_configure_base_flows.py
index 5f6f93c881..dabc5be6b7 100755
--- a/plugins/xenserver/networking/etc/xensource/scripts/ovs_configure_base_flows.py
+++ b/plugins/xenserver/networking/etc/xensource/scripts/ovs_configure_base_flows.py
@@ -30,9 +30,8 @@ import novalib
 def main(command, phys_dev_name):
     ovs_ofctl = lambda *rule: novalib.execute('/usr/bin/ovs-ofctl', *rule)
 
-    bridge_name = \
-        novalib.execute_get_output('/usr/bin/ovs-vsctl',
-                                    'iface-to-br', phys_dev_name)
+    bridge_name = novalib.execute_get_output('/usr/bin/ovs-vsctl',
+                                             'iface-to-br', phys_dev_name)
 
     # always clear all flows first
     ovs_ofctl('del-flows', bridge_name)
@@ -50,9 +49,9 @@ def main(command, phys_dev_name):
 
         # Allow traffic from dom0 if there is a management interface
         # present (its IP address is on the bridge itself)
-        bridge_addr = \
-            novalib.execute_get_output('/sbin/ip', '-o', '-f', 'inet', 'addr',
-                                                    'show', bridge_name)
+        bridge_addr = novalib.execute_get_output('/sbin/ip', '-o', '-f',
+                                                 'inet', 'addr', 'show',
+                                                 bridge_name)
         if bridge_addr != '':
             ovs_ofctl('add-flow', bridge_name,
                       "priority=2,in_port=LOCAL,actions=normal")
diff --git a/plugins/xenserver/networking/etc/xensource/scripts/ovs_configure_vif_flows.py b/plugins/xenserver/networking/etc/xensource/scripts/ovs_configure_vif_flows.py
index c2a029de38..6e41e1e19c 100755
--- a/plugins/xenserver/networking/etc/xensource/scripts/ovs_configure_vif_flows.py
+++ b/plugins/xenserver/networking/etc/xensource/scripts/ovs_configure_vif_flows.py
@@ -95,8 +95,8 @@ def main(command, vif_raw, net_type):
                         apply_ovs_ipv4_flows(ovs, bridge, params)
                 if net_type in ('ipv6', 'all') and 'ip6s' in data:
                     for ip6 in data['ip6s']:
-                        link_local = str(netaddr.EUI(data['mac']).eui64()\
-                                        .ipv6_link_local())
+                        mac_eui64 = netaddr.EUI(data['mac']).eui64()
+                        link_local = str(mac_eui64.ipv6_link_local())
                         ovs.params.update({'IPV6_LINK_LOCAL_ADDR': link_local})
                         ovs.params.update({'IPV6_GLOBAL_ADDR': ip6['ip']})
                         apply_ovs_ipv6_flows(ovs, bridge, params)
@@ -228,8 +228,8 @@ def apply_ovs_ipv6_flows(ovs, bridge, params):
 
 if __name__ == "__main__":
     if len(sys.argv) != 4:
-        print "usage: %s [online|offline] vif-domid-idx [ipv4|ipv6|all] " % \
-               os.path.basename(sys.argv[0])
+        print ("usage: %s [online|offline] vif-domid-idx [ipv4|ipv6|all] " %
+               os.path.basename(sys.argv[0]))
         sys.exit(1)
     else:
         command, vif_raw, net_type = sys.argv[1:4]
diff --git a/plugins/xenserver/networking/etc/xensource/scripts/vif_rules.py b/plugins/xenserver/networking/etc/xensource/scripts/vif_rules.py
index 157ecc298b..106525a160 100755
--- a/plugins/xenserver/networking/etc/xensource/scripts/vif_rules.py
+++ b/plugins/xenserver/networking/etc/xensource/scripts/vif_rules.py
@@ -125,8 +125,8 @@ def apply_ebtables_rules(command, params):
 
 if __name__ == "__main__":
     if len(sys.argv) < 3:
-        print "usage: %s dom_id online|offline [vif]" % \
-               os.path.basename(sys.argv[0])
+        print ("usage: %s dom_id online|offline [vif]" %
+               os.path.basename(sys.argv[0]))
         sys.exit(1)
     else:
         dom_id, command = sys.argv[1:3]
diff --git a/plugins/xenserver/xenapi/etc/xapi.d/plugins/glance b/plugins/xenserver/xenapi/etc/xapi.d/plugins/glance
index daf4576bf5..76e9349d42 100755
--- a/plugins/xenserver/xenapi/etc/xapi.d/plugins/glance
+++ b/plugins/xenserver/xenapi/etc/xapi.d/plugins/glance
@@ -146,8 +146,8 @@ def _download_tarball(sr_path, image_id, glance_host, glance_port, auth_token):
     if auth_token:
         headers['x-auth-token'] = auth_token
 
-    url = "http://%(glance_host)s:%(glance_port)d/v1/images/"\
-          "%(image_id)s" % locals()
+    url = ("http://%(glance_host)s:%(glance_port)d/v1/images/"
+           "%(image_id)s" % locals())
     logging.info("Downloading %s" % url)
 
     request = urllib2.Request(url, headers=headers)
diff --git a/smoketests/run_tests.py b/smoketests/run_tests.py
index 62bdfbec61..30592b6a3f 100644
--- a/smoketests/run_tests.py
+++ b/smoketests/run_tests.py
@@ -133,9 +133,9 @@ class _Win32Colorizer(object):
     See _AnsiColorizer docstring.
     """
     def __init__(self, stream):
-        from win32console import GetStdHandle, STD_OUT_HANDLE, \
-             FOREGROUND_RED, FOREGROUND_BLUE, FOREGROUND_GREEN, \
-             FOREGROUND_INTENSITY
+        from win32console import (GetStdHandle, STD_OUT_HANDLE,
+                                  FOREGROUND_RED, FOREGROUND_GREEN,
+                                  FOREGROUND_BLUE, FOREGROUND_INTENSITY)
         red, green, blue, bold = (FOREGROUND_RED, FOREGROUND_GREEN,
                                   FOREGROUND_BLUE, FOREGROUND_INTENSITY)
         self.stream = stream
@@ -291,8 +291,8 @@ class NovaTestRunner(core.TextTestRunner):
 
 if __name__ == '__main__':
     if not os.getenv('EC2_ACCESS_KEY'):
-        print _('Missing EC2 environment variables. Please ' \
-                'source the appropriate novarc file before ' \
+        print _('Missing EC2 environment variables. Please '
+                'source the appropriate novarc file before '
                 'running this test.')
         sys.exit(1)
 
diff --git a/tools/db/schema_diff.py b/tools/db/schema_diff.py
index 7408978e57..873f20543f 100755
--- a/tools/db/schema_diff.py
+++ b/tools/db/schema_diff.py
@@ -233,8 +233,8 @@ def main():
     ORIG_DUMP = ORIG_DB + ".dump"
     NEW_DUMP = NEW_DB + ".dump"
 
-    db_type, orig_branch, orig_version, new_branch, new_version =\
-            parse_options()
+    options = parse_options()
+    db_type, orig_branch, orig_version, new_branch, new_version = options
 
     # Since we're going to be switching branches, ensure user doesn't have any
     # uncommited changes
diff --git a/tools/esx/guest_tool.py b/tools/esx/guest_tool.py
index 9cda7e35c5..e7b742cc0f 100644
--- a/tools/esx/guest_tool.py
+++ b/tools/esx/guest_tool.py
@@ -119,21 +119,20 @@ def _get_windows_network_adapters():
     wbem_service = wbem_locator.ConnectServer('.', 'root\cimv2')
     wbem_network_adapters = wbem_service.InstancesOf('Win32_NetworkAdapter')
     network_adapters = []
-    for wbem_network_adapter in wbem_network_adapters:
-        if wbem_network_adapter.NetConnectionStatus == 2 or \
-                                wbem_network_adapter.NetConnectionStatus == 7:
-            adapter_name = wbem_network_adapter.NetConnectionID
-            mac_address = wbem_network_adapter.MacAddress.lower()
-            wbem_network_adapter_config = \
-                wbem_network_adapter.associators_(
+    for adapter in wbem_network_adapters:
+        if (adapter.NetConnectionStatus == 2 or
+            adapter.NetConnectionStatus == 7):
+            adapter_name = adapter.NetConnectionID
+            mac_address = adapter.MacAddress.lower()
+            config = adapter.associators_(
                           'Win32_NetworkAdapterSetting',
                           'Win32_NetworkAdapterConfiguration')[0]
             ip_address = ''
             subnet_mask = ''
-            if wbem_network_adapter_config.IPEnabled:
-                ip_address = wbem_network_adapter_config.IPAddress[0]
-                subnet_mask = wbem_network_adapter_config.IPSubnet[0]
-                #wbem_network_adapter_config.DefaultIPGateway[0]
+            if config.IPEnabled:
+                ip_address = config.IPAddress[0]
+                subnet_mask = config.IPSubnet[0]
+                #config.DefaultIPGateway[0]
             network_adapters.append({'name': adapter_name,
                                     'mac-address': mac_address,
                                     'ip-address': ip_address,
@@ -160,9 +159,8 @@ def _get_linux_network_adapters():
         sock.fileno(),
         0x8912,
         struct.pack('iL', max_bytes, names.buffer_info()[0])))[0]
-    adapter_names = \
-        [names.tostring()[n_counter:n_counter + offset1].split('\0', 1)[0]
-        for n_counter in xrange(0, outbytes, offset2)]
+    adapter_names = [names.tostring()[n_cnt:n_cnt + offset1].split('\0', 1)[0]
+                     for n_cnt in xrange(0, outbytes, offset2)]
     network_adapters = []
     for adapter_name in adapter_names:
         ip_address = socket.inet_ntoa(fcntl.ioctl(
@@ -257,10 +255,10 @@ def _windows_set_networking():
         cmd = ['"' + vmware_tools_bin + '"', '--cmd', 'machine.id.get']
         for network_detail in _parse_network_details(_execute(cmd,
                                               check_exit_code=False)):
-            mac_address, ip_address, subnet_mask, gateway, broadcast,\
-                dns_servers = network_detail
-            adapter_name, current_ip_address = \
-                    _get_win_adapter_name_and_ip_address(mac_address)
+            (mac_address, ip_address, subnet_mask, gateway, broadcast,
+             dns_servers) = network_detail
+            name_and_ip = _get_win_adapter_name_and_ip_address(mac_address)
+            adapter_name, current_ip_address = name_and_ip
             if adapter_name and not ip_address == current_ip_address:
                 cmd = ['netsh', 'interface', 'ip', 'set', 'address',
                        'name="%s"' % adapter_name, 'source=static', ip_address,
@@ -289,14 +287,14 @@ def _set_rhel_networking(network_details=None):
     network_details = network_details or []
     all_dns_servers = []
     for network_detail in network_details:
-        mac_address, ip_address, subnet_mask, gateway, broadcast,\
-            dns_servers = network_detail
+        (mac_address, ip_address, subnet_mask, gateway, broadcast,
+         dns_servers) = network_detail
         all_dns_servers.extend(dns_servers)
-        adapter_name, current_ip_address = \
-                _get_linux_adapter_name_and_ip_address(mac_address)
+        name_and_ip = _get_linux_adapter_name_and_ip_address(mac_address)
+        adapter_name, current_ip_address = name_and_ip
         if adapter_name and not ip_address == current_ip_address:
-            interface_file_name = \
-                '/etc/sysconfig/network-scripts/ifcfg-%s' % adapter_name
+            interface_file_name = ('/etc/sysconfig/network-scripts/ifcfg-%s' %
+                                   adapter_name)
             # Remove file
             os.remove(interface_file_name)
             # Touch file
@@ -337,11 +335,11 @@ def _set_ubuntu_networking(network_details=None):
     _execute(['touch', interface_file_name])
     interface_file = open(interface_file_name, 'w')
     for device, network_detail in enumerate(network_details):
-        mac_address, ip_address, subnet_mask, gateway, broadcast,\
-            dns_servers = network_detail
+        (mac_address, ip_address, subnet_mask, gateway, broadcast,
+         dns_servers) = network_detail
         all_dns_servers.extend(dns_servers)
-        adapter_name, current_ip_address = \
-                _get_linux_adapter_name_and_ip_address(mac_address)
+        name_and_ip = _get_linux_adapter_name_and_ip_address(mac_address)
+        adapter_name, current_ip_address = name_and_ip
 
         if adapter_name:
             interface_file.write('\nauto %s' % adapter_name)
diff --git a/tools/hacking.py b/tools/hacking.py
index 7fea734b69..93e51e66cc 100755
--- a/tools/hacking.py
+++ b/tools/hacking.py
@@ -48,8 +48,8 @@ VERBOSE_MISSING_IMPORT = False
 
 
 def is_import_exception(mod):
-    return mod in IMPORT_EXCEPTIONS or \
-        any(mod.startswith(m + '.') for m in IMPORT_EXCEPTIONS)
+    return (mod in IMPORT_EXCEPTIONS or
+            any(mod.startswith(m + '.') for m in IMPORT_EXCEPTIONS))
 
 
 def import_normalize(line):
@@ -114,9 +114,9 @@ def nova_one_import_per_line(logical_line):
     """
     pos = logical_line.find(',')
     parts = logical_line.split()
-    if pos > -1 and (parts[0] == "import" or
-       parts[0] == "from" and parts[2] == "import") and \
-       not is_import_exception(parts[1]):
+    if (pos > -1 and (parts[0] == "import" or
+                      parts[0] == "from" and parts[2] == "import") and
+        not is_import_exception(parts[1])):
         return pos, "NOVA N301: one import per line"
 
 _missingImport = set([])
diff --git a/tools/install_venv.py b/tools/install_venv.py
index ffc5417e89..8594da978c 100644
--- a/tools/install_venv.py
+++ b/tools/install_venv.py
@@ -143,8 +143,8 @@ class Fedora(Distro):
 
 
 def get_distro():
-    if os.path.exists('/etc/fedora-release') or \
-       os.path.exists('/etc/redhat-release'):
+    if (os.path.exists('/etc/fedora-release') or
+        os.path.exists('/etc/redhat-release')):
         return Fedora()
     else:
         return Distro()