Remove trivial cases of unused variables (1)

Kill some of the variables marked as unused by flakes8. This should
allow to enable F841 check in the future.
Only trivial cases with no function calls and obviously pure functions
(like datetime.now(), or len()) are cleaned up here.

Part 1, split to reduce conflicts.

Change-Id: I82854349574ec4bcb9336aba626eefdaed81a8c8

22 files changed, 28 insertions, 44 deletions

diff --git a/nova/api/ec2/cloud.py b/nova/api/ec2/cloud.py
index 47575b201..e02f7b6f9 100644
--- a/nova/api/ec2/cloud.py
+++ b/nova/api/ec2/cloud.py
@@ -802,7 +802,6 @@ class CloudController(object):
             'detaching': 'in-use'}
 
         instance_ec2_id = None
-        instance_data = None
 
         if volume.get('instance_uuid', None):
             instance_uuid = volume['instance_uuid']
@@ -810,8 +809,7 @@ class CloudController(object):
                     instance_uuid)
 
             instance_ec2_id = ec2utils.id_to_ec2_inst_id(instance_uuid)
-            instance_data = '%s[%s]' % (instance_ec2_id,
-                                        instance['host'])
+
         v = {}
         v['volumeId'] = ec2utils.id_to_ec2_vol_id(volume['id'])
         v['status'] = valid_ec2_api_volume_status_map.get(volume['status'],
diff --git a/nova/api/metadata/password.py b/nova/api/metadata/password.py
index f3453e945..50f6c94ac 100644
--- a/nova/api/metadata/password.py
+++ b/nova/api/metadata/password.py
@@ -49,7 +49,6 @@ def convert_password(context, password):
 
 def handle_password(req, meta_data):
     ctxt = context.get_admin_context()
-    password = meta_data.password
     if req.method == 'GET':
         return meta_data.password
     elif req.method == 'POST':
diff --git a/nova/api/openstack/compute/contrib/attach_interfaces.py b/nova/api/openstack/compute/contrib/attach_interfaces.py
index ec565a0d1..a823eed2b 100644
--- a/nova/api/openstack/compute/contrib/attach_interfaces.py
+++ b/nova/api/openstack/compute/contrib/attach_interfaces.py
@@ -60,7 +60,7 @@ class InterfaceAttachmentController(object):
 
         port_id = id
         try:
-            instance = self.compute_api.get(context, server_id)
+            self.compute_api.get(context, server_id)
         except exception.NotFound:
             raise exc.HTTPNotFound()
 
diff --git a/nova/api/openstack/compute/contrib/extended_ips.py b/nova/api/openstack/compute/contrib/extended_ips.py
index ac75293a6..20356c08d 100644
--- a/nova/api/openstack/compute/contrib/extended_ips.py
+++ b/nova/api/openstack/compute/contrib/extended_ips.py
@@ -94,7 +94,7 @@ def make_server(elem):
 class ExtendedIpsServerTemplate(xmlutil.TemplateBuilder):
     def construct(self):
         root = xmlutil.TemplateElement('server', selector='server')
-        elem = xmlutil.SubTemplateElement(root, 'server', selector='servers')
+        xmlutil.SubTemplateElement(root, 'server', selector='servers')
         make_server(root)
         return xmlutil.SlaveTemplate(root, 1, nsmap={
             Extended_ips.alias: Extended_ips.namespace})
diff --git a/nova/api/openstack/compute/contrib/fixed_ips.py b/nova/api/openstack/compute/contrib/fixed_ips.py
index b474b685d..532282a2b 100644
--- a/nova/api/openstack/compute/contrib/fixed_ips.py
+++ b/nova/api/openstack/compute/contrib/fixed_ips.py
@@ -69,8 +69,7 @@ class FixedIPController(object):
             fixed_ip = db.fixed_ip_get_by_address(context, address)
             db.fixed_ip_update(context, fixed_ip['address'],
                                {'reserved': reserved})
-        except (exception.FixedIpNotFoundForAddress,
-                exception.FixedIpInvalid) as ex:
+        except (exception.FixedIpNotFoundForAddress, exception.FixedIpInvalid):
             msg = _("Fixed IP %s not found") % address
             raise webob.exc.HTTPNotFound(explanation=msg)
 
diff --git a/nova/api/openstack/compute/contrib/flavorextraspecs.py b/nova/api/openstack/compute/contrib/flavorextraspecs.py
index 6e33d3603..00e7d7233 100644
--- a/nova/api/openstack/compute/contrib/flavorextraspecs.py
+++ b/nova/api/openstack/compute/contrib/flavorextraspecs.py
@@ -104,7 +104,7 @@ class FlavorExtraSpecsController(object):
             extra_spec = db.instance_type_extra_specs_get_item(context,
                                                                flavor_id, id)
             return extra_spec
-        except exception.InstanceTypeExtraSpecsNotFound as e:
+        except exception.InstanceTypeExtraSpecsNotFound:
             raise exc.HTTPNotFound()
 
     def delete(self, req, flavor_id, id):
diff --git a/nova/api/openstack/compute/contrib/services.py b/nova/api/openstack/compute/contrib/services.py
index 3a637010a..76eec7ce4 100644
--- a/nova/api/openstack/compute/contrib/services.py
+++ b/nova/api/openstack/compute/contrib/services.py
@@ -183,8 +183,7 @@ class ServiceController(object):
             raise webob.exc.HTTPUnprocessableEntity(detail=msg)
 
         try:
-            svc = self.host_api.service_update(context, host, binary,
-                                               status_detail)
+            self.host_api.service_update(context, host, binary, status_detail)
         except exception.ServiceNotFound:
             raise webob.exc.HTTPNotFound(_("Unknown service"))
 
diff --git a/nova/api/openstack/compute/servers.py b/nova/api/openstack/compute/servers.py
index 67d64127a..b65aa3f48 100644
--- a/nova/api/openstack/compute/servers.py
+++ b/nova/api/openstack/compute/servers.py
@@ -552,10 +552,10 @@ class Controller(wsgi.Controller):
                                                      search_opts=search_opts,
                                                      limit=limit,
                                                      marker=marker)
-        except exception.MarkerNotFound as e:
+        except exception.MarkerNotFound:
             msg = _('marker [%s] not found') % marker
             raise exc.HTTPBadRequest(explanation=msg)
-        except exception.FlavorNotFound as e:
+        except exception.FlavorNotFound:
             log_msg = _("Flavor '%s' could not be found ")
             LOG.debug(log_msg, search_opts['flavor'])
             instance_list = []
@@ -1094,11 +1094,11 @@ class Controller(wsgi.Controller):
         except exception.InstanceInvalidState as state_error:
             common.raise_http_conflict_for_instance_invalid_state(state_error,
                     'resize')
-        except exception.ImageNotAuthorized as image_error:
+        except exception.ImageNotAuthorized:
             msg = _("You are not authorized to access the image "
                     "the instance was started with.")
             raise exc.HTTPUnauthorized(explanation=msg)
-        except exception.ImageNotFound as image_error:
+        except exception.ImageNotFound:
             msg = _("Image that the instance was started "
                     "with could not be found.")
             raise exc.HTTPBadRequest(explanation=msg)
diff --git a/nova/cmd/manage.py b/nova/cmd/manage.py
index 46e6d371f..df54e8677 100644
--- a/nova/cmd/manage.py
+++ b/nova/cmd/manage.py
@@ -72,7 +72,6 @@ from nova.openstack.common.db import exception as db_exc
 from nova.openstack.common import importutils
 from nova.openstack.common import log as logging
 from nova.openstack.common import rpc
-from nova.openstack.common import timeutils
 from nova import quota
 from nova import servicegroup
 from nova import version
@@ -655,7 +654,6 @@ class ServiceCommands(object):
         """
         servicegroup_api = servicegroup.API()
         ctxt = context.get_admin_context()
-        now = timeutils.utcnow()
         services = db.service_get_all(ctxt)
         services = availability_zones.set_availability_zones(ctxt, services)
         if host:
@@ -1003,13 +1001,12 @@ class AgentBuildCommands(object):
                 hypervisor='xen'):
         """Creates a new agent build."""
         ctxt = context.get_admin_context()
-        agent_build = db.agent_build_create(ctxt,
-                                            {'hypervisor': hypervisor,
-                                             'os': os,
-                                             'architecture': architecture,
-                                             'version': version,
-                                             'url': url,
-                                             'md5hash': md5hash})
+        db.agent_build_create(ctxt, {'hypervisor': hypervisor,
+                                     'os': os,
+                                     'architecture': architecture,
+                                     'version': version,
+                                     'url': url,
+                                     'md5hash': md5hash})
 
     def delete(self, os, architecture, hypervisor='xen'):
         """Deletes an existing agent build."""
diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 2ae435f9a..3e380cb6e 100755
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -494,7 +494,7 @@ class ComputeManager(manager.SchedulerDependentManager):
                           'assuming it\'s not on shared storage'),
                         instance=instance)
             shared_storage = False
-        except Exception as e:
+        except Exception:
             LOG.exception(_('Failed to check if instance shared'),
                       instance=instance)
         finally:
diff --git a/nova/conductor/api.py b/nova/conductor/api.py
index 150c9a41d..3f955d24f 100644
--- a/nova/conductor/api.py
+++ b/nova/conductor/api.py
@@ -395,7 +395,7 @@ class API(LocalAPI):
                 self.base_rpcapi.ping(context, '1.21 GigaWatts',
                                       timeout=timeout)
                 break
-            except rpc_common.Timeout as e:
+            except rpc_common.Timeout:
                 LOG.warning(_('Timed out waiting for nova-conductor. '
                                 'Is it running? Or did this service start '
                                 'before nova-conductor?'))
diff --git a/nova/db/sqlalchemy/migrate_repo/versions/186_new_bdm_format.py b/nova/db/sqlalchemy/migrate_repo/versions/186_new_bdm_format.py
index 88462a2c8..e8b9a1570 100644
--- a/nova/db/sqlalchemy/migrate_repo/versions/186_new_bdm_format.py
+++ b/nova/db/sqlalchemy/migrate_repo/versions/186_new_bdm_format.py
@@ -111,9 +111,6 @@ def _upgrade_bdm_v2(meta, bdm_table, bdm_shadow_table):
     _bdm_rows_v1 = ('id', 'device_name', 'virtual_name',
                     'snapshot_id', 'volume_id', 'instance_uuid')
 
-    _bdm_rows_v2 = ('id', 'source_type', 'destination_type', 'guest_format',
-                    'device_type', 'disk_bus', 'boot_index', 'image_id')
-
     _instance_cols = ('uuid', 'image_ref', 'root_device_name')
 
     def _get_columns(table, names):
diff --git a/nova/db/sqlalchemy/utils.py b/nova/db/sqlalchemy/utils.py
index 7430fefdd..a429f1dfe 100644
--- a/nova/db/sqlalchemy/utils.py
+++ b/nova/db/sqlalchemy/utils.py
@@ -70,7 +70,7 @@ def visit_insert_from_select(element, compiler, **kw):
 def _get_not_supported_column(col_name_col_instance, column_name):
     try:
         column = col_name_col_instance[column_name]
-    except Exception as e:
+    except Exception:
         msg = _("Please specify column %s in col_name_col_instance "
                 "param. It is required because column has unsupported "
                 "type by sqlite).")
diff --git a/nova/image/s3.py b/nova/image/s3.py
index 42cb97170..a1ae55b4e 100644
--- a/nova/image/s3.py
+++ b/nova/image/s3.py
@@ -198,13 +198,11 @@ class S3ImageService(object):
     def _s3_parse_manifest(self, context, metadata, manifest):
         manifest = etree.fromstring(manifest)
         image_format = 'ami'
-        image_type = 'machine'
 
         try:
             kernel_id = manifest.find('machine_configuration/kernel_id').text
             if kernel_id == 'true':
                 image_format = 'aki'
-                image_type = 'kernel'
                 kernel_id = None
         except Exception:
             kernel_id = None
@@ -213,7 +211,6 @@ class S3ImageService(object):
             ramdisk_id = manifest.find('machine_configuration/ramdisk_id').text
             if ramdisk_id == 'true':
                 image_format = 'ari'
-                image_type = 'ramdisk'
                 ramdisk_id = None
         except Exception:
             ramdisk_id = None
@@ -270,7 +267,7 @@ class S3ImageService(object):
 
         #TODO(bcwaldon): right now, this removes user-defined ids.
         # We need to re-enable this.
-        image_id = metadata.pop('id', None)
+        metadata.pop('id', None)
 
         image = self.service.create(context, metadata)
 
diff --git a/nova/network/model.py b/nova/network/model.py
index 240911ea9..4efa70ab6 100644
--- a/nova/network/model.py
+++ b/nova/network/model.py
@@ -72,7 +72,7 @@ class IP(Model):
         if self['address'] and not self['version']:
             try:
                 self['version'] = netaddr.IPAddress(self['address']).version
-            except netaddr.AddrFormatError as e:
+            except netaddr.AddrFormatError:
                 raise exception.InvalidIpAddressError(self['address'])
 
     def __eq__(self, other):
diff --git a/nova/network/quantumv2/api.py b/nova/network/quantumv2/api.py
index 3721d53b1..bfebeeeb6 100644
--- a/nova/network/quantumv2/api.py
+++ b/nova/network/quantumv2/api.py
@@ -325,7 +325,7 @@ class API(base.Base):
         for port in ports:
             try:
                 quantumv2.get_client(context).delete_port(port['id'])
-            except Exception as ex:
+            except Exception:
                 LOG.exception(_("Failed to delete quantum port %(portid)s ")
                               % {'portid': port['id']})
 
diff --git a/nova/scheduler/filters/trusted_filter.py b/nova/scheduler/filters/trusted_filter.py
index bb1962ebe..522a68096 100644
--- a/nova/scheduler/filters/trusted_filter.py
+++ b/nova/scheduler/filters/trusted_filter.py
@@ -153,7 +153,7 @@ class AttestationService(object):
                 return httplib.OK, res
             return status_code, None
 
-        except (socket.error, IOError) as e:
+        except (socket.error, IOError):
             return IOError, None
 
     def _request(self, cmd, subcmd, hosts):
diff --git a/nova/service.py b/nova/service.py
index 0377ba44b..715040323 100644
--- a/nova/service.py
+++ b/nova/service.py
@@ -286,7 +286,7 @@ class Service(service.Service):
         """Perform basic config checks before starting processing."""
         # Make sure the tempdir exists and is writable
         try:
-            with utils.tempdir() as tmpdir:
+            with utils.tempdir():
                 pass
         except Exception as e:
             LOG.error(_('Temporary directory is invalid: %s'), e)
diff --git a/nova/vnc/xvp_proxy.py b/nova/vnc/xvp_proxy.py
index 4331e5b40..920f24b7a 100644
--- a/nova/vnc/xvp_proxy.py
+++ b/nova/vnc/xvp_proxy.py
@@ -57,7 +57,7 @@ class XCPVNCProxy(object):
         while True:
             try:
                 d = source.recv(32384)
-            except Exception as e:
+            except Exception:
                 d = None
 
             # If recv fails, send a write shutdown the other direction
@@ -68,7 +68,7 @@ class XCPVNCProxy(object):
             try:
                 # sendall raises an exception on write error, unlike send
                 dest.sendall(d)
-            except Exception as e:
+            except Exception:
                 source.close()
                 dest.close()
                 break
@@ -102,7 +102,6 @@ class XCPVNCProxy(object):
 
         client = req.environ['eventlet.input'].get_socket()
         client.sendall("HTTP/1.1 200 OK\r\n\r\n")
-        socketsserver = None
         sockets['client'] = client
         sockets['server'] = server
 
diff --git a/smoketests/base.py b/smoketests/base.py
index 1ecb5a92e..c3b2be131 100644
--- a/smoketests/base.py
+++ b/smoketests/base.py
@@ -98,7 +98,7 @@ class SmokeTestCase(unittest.TestCase):
             try:
                 conn = self.connect_ssh(ip, key_name)
                 conn.close()
-            except Exception as e:
+            except Exception:
                 time.sleep(wait)
             else:
                 return True
diff --git a/smoketests/public_network_smoketests.py b/smoketests/public_network_smoketests.py
index f20b0923e..9b68a8fc7 100644
--- a/smoketests/public_network_smoketests.py
+++ b/smoketests/public_network_smoketests.py
@@ -96,7 +96,7 @@ class InstanceTestsFromPublic(base.UserSmokeTestCase):
                     conn = self.connect_ssh(
                                         self.data['ip_v6'], TEST_KEY)
                     conn.close()
-                except Exception as ex:
+                except Exception:
                     time.sleep(1)
                 else:
                     break
diff --git a/smoketests/test_sysadmin.py b/smoketests/test_sysadmin.py
index b05f0ac4b..d45a75b74 100644
--- a/smoketests/test_sysadmin.py
+++ b/smoketests/test_sysadmin.py
@@ -161,7 +161,6 @@ class InstanceTests(base.UserSmokeTestCase):
         self.data['instance'] = reservation.instances[0]
 
     def test_003_instance_runs_within_60_seconds(self):
-        instance = self.data['instance']
         # allow 60 seconds to exit pending with IP
         if not self.wait_for_running(self.data['instance']):
             self.fail('instance failed to start')