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

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'],

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':

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()
 

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})

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)
 

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):

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"))
 

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)

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."""

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:

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?'))

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):

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).")

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)
 

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):

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']})
 

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):

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)

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
 

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

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

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')