Bump pylint version to support python 3.8

As spotted in Focal testing patch [0], pep8 test fails with many
C0321 false-positives, reported in pylint as current version does not
support python 3.8 [1]

Use a newer version of pylint and astroid, fixing or disabling some of
the new checks: no-else-*, unnecessary-comprehension, import-outside-toplevel

[0] https://review.opendev.org/#/c/738163/
[1] https://github.com/PyCQA/pylint/issues/2737

Change-Id: Ie646b7093aa8634fd950c136a0eba9adcf56591c

neutron/agent/common/async_process.py

@@ -112,7 +112,6 @@ class AsyncProcess(object):
         LOG.debug('Launching async process [%s].', self.cmd)
         if self._is_running:
             raise AsyncProcessException(_('Process is already started'))
-        else:
         self._spawn()
 
         if block:

neutron/agent/linux/dhcp.py

@@ -951,7 +951,6 @@ class Dnsmasq(DhcpLocalProcess):
                     if line.startswith('duid'):
                         if not server_id:
                             server_id = line.strip().split()[1]
-                            continue
                         else:
                             LOG.warning('Multiple DUID entries in %s '
                                         'lease file, dnsmasq is possibly '

neutron/agent/linux/iptables_firewall.py

@@ -429,13 +429,11 @@ class IptablesFirewallDriver(firewall.FirewallDriver):
                     if self.enable_ipset:
                         port_sg_rules.append(rule)
                         break
-                    else:
                     port_sg_rules.extend(
                         self._expand_sg_rule_with_remote_ips(
                             rule, port, constants.INGRESS_DIRECTION))
                     if port_sg_rules:
                         break
-                        else:
                     port_sg_rules.extend(
                         self._expand_sg_rule_with_remote_ips(
                             rule, port, constants.EGRESS_DIRECTION))

neutron/agent/linux/iptables_manager.py

@@ -848,7 +848,7 @@ def _generate_chain_diff_iptables_commands(chain, old_chain_rules,
         if line.startswith('?'):
             # skip ? because that's a guide string for intraline differences
             continue
-        elif line.startswith('-'):  # line deleted
+        if line.startswith('-'):  # line deleted
             statements.append('-D %s %d' % (chain, old_index))
             # since we are removing a line from the old rules, we
             # backup the index by 1

neutron/agent/linux/l3_tc_lib.py

@@ -69,14 +69,14 @@ class FloatingIPTcCommandBase(ip_lib.IPDevice):
                 filter_id = m.group(2)
                 # It matched, so ip/32 is not here. continue
                 continue
-            elif not line.startswith('match'):
+            if not line.startswith('match'):
                 continue
             parts = line.split(" ")
             if ip + '/32' in parts:
                 filterids_for_ip.append(filter_id)
         if len(filterids_for_ip) > 1:
             raise exceptions.MultipleFilterIDForIPFound(ip=ip)
-        elif len(filterids_for_ip) == 0:
+        if len(filterids_for_ip) == 0:
             raise exceptions.FilterIDForIPNotFound(ip=ip)
         return filterids_for_ip[0]
 

neutron/agent/linux/openvswitch_firewall/iptables.py

@@ -22,6 +22,7 @@ def get_device_port_name(port_id):
 
 def get_iptables_driver_instance():
     """Load hybrid iptables firewall driver."""
+    # pylint: disable=import-outside-toplevel
     from neutron.agent.linux import iptables_firewall
 
     class HybridIptablesHelper(

neutron/agent/ovsdb/native/connection.py

@@ -51,7 +51,7 @@ def configure_ssl_conn():
     for ssl_opt, ssl_file in req_ssl_opts.items():
         if not ssl_file:
             raise ovsdb_exc.OvsdbSslRequiredOptError(ssl_opt=ssl_opt)
-        elif not os.path.exists(ssl_file):
+        if not os.path.exists(ssl_file):
             raise ovsdb_exc.OvsdbSslConfigNotFound(ssl_file=ssl_file)
     # TODO(ihrachys): move to ovsdbapp
     Stream.ssl_set_private_key_file(req_ssl_opts['ssl_key_file'])

neutron/api/extensions.py

@@ -394,7 +394,6 @@ class ExtensionManager(object):
         if not faulty_extensions <= default_extensions:
             raise exceptions.ExtensionsNotFound(
                 extensions=list(faulty_extensions))
-        else:
         # Remove the faulty extensions so that they do not show during
         # ext-list
         for ext in faulty_extensions:

neutron/api/rpc/handlers/securitygroups_rpc.py

@@ -288,7 +288,7 @@ class SecurityGroupServerAPIShim(sg_rpc_base.SecurityGroupInfoAPIMixin):
                                             'allowed_address_pairs'}):
             # none of the relevant fields to SG calculations changed
             return
-        sgs.update({sg_id for sg_id in updated.security_group_ids})
+        sgs.update(set(updated.security_group_ids))
         if sgs:
             self._sg_agent.security_groups_member_updated(sgs)
 

neutron/cmd/sanity/checks.py

@@ -81,6 +81,7 @@ def patch_supported():
 
 def nova_notify_supported():
     try:
+        # pylint:disable=import-outside-toplevel
         import neutron.notifiers.nova  # noqa since unused
         return True
     except ImportError:

neutron/common/eventlet_utils.py

@@ -40,6 +40,7 @@ def monkey_patch():
     # Monkey patch the original current_thread to use the up-to-date _active
     # global variable. See https://bugs.launchpad.net/bugs/1863021 and
     # https://github.com/eventlet/eventlet/issues/592
+    # pylint: disable=import-outside-toplevel
     import __original_module_threading as orig_threading
     import threading  # noqa
     orig_threading.current_thread.__globals__['_active'] = threading._active

neutron/common/ovn/utils.py

@@ -420,7 +420,7 @@ def get_system_dns_resolvers(resolver_file=DNS_RESOLVER_FILE):
 
 
 def get_port_subnet_ids(port):
-    fixed_ips = [ip for ip in port['fixed_ips']]
+    fixed_ips = list(port['fixed_ips'])
     return [f['subnet_id'] for f in fixed_ips]
 
 

neutron/conf/db/migration_cli.py

@@ -22,7 +22,7 @@ migration_entrypoints = {
     for entrypoint in pkg_resources.iter_entry_points(MIGRATION_ENTRYPOINTS)
 }
 
-INSTALLED_SUBPROJECTS = [project_ for project_ in migration_entrypoints]
+INSTALLED_SUBPROJECTS = list(migration_entrypoints)
 
 CORE_OPTS = [
     cfg.StrOpt('subproject',

neutron/db/agentschedulers_db.py

@@ -146,7 +146,6 @@ class AgentSchedulerDbMixin(agents_db.AgentDbMixin):
                 binding_resource_id = getattr(binding, resource_id_attr)
                 if binding_agent_id in agents_back_online:
                     continue
-                else:
                 # we need new context to make sure we use different DB
                 # transaction - otherwise we may fetch same agent record
                 # each time due to REPEATABLE_READ isolation level
@@ -299,8 +298,7 @@ class DhcpAgentSchedulerDbMixin(dhcpagentscheduler
             down_bindings = network.NetworkDhcpAgentBinding.get_down_bindings(
                 context, cutoff)
             dhcp_notifier = self.agent_notifiers.get(constants.AGENT_TYPE_DHCP)
-            dead_bindings = [b for b in
-                             self._filter_bindings(context, down_bindings)]
+            dead_bindings = list(self._filter_bindings(context, down_bindings))
             agents = self.get_agent_objects(
                 context, {'agent_type': [constants.AGENT_TYPE_DHCP]})
             if not agents:

neutron/db/db_base_plugin_v2.py

@@ -158,6 +158,7 @@ class NeutronDbPluginV2(db_base_plugin_common.DbBasePluginCommon,
                 cfg.CONF.notify_nova_on_port_data_changes):
             # Import nova conditionally to support the use case of Neutron
             # being used outside of an OpenStack context.
+            # pylint: disable=import-outside-toplevel
             from neutron.notifiers import nova
             self.nova_notifier = nova.Notifier.get_instance()
             # NOTE(arosen) These event listeners are here to hook into when
@@ -172,6 +173,7 @@ class NeutronDbPluginV2(db_base_plugin_common.DbBasePluginCommon,
                     self.nova_notifier.record_port_status_changed)
         if cfg.CONF.ironic.enable_notifications:
             # Import ironic notifier conditionally
+            # pylint: disable=import-outside-toplevel
             from neutron.notifiers import ironic
             self.ironic_notifier = ironic.Notifier.get_instance()
 
@@ -600,11 +602,11 @@ class NeutronDbPluginV2(db_base_plugin_common.DbBasePluginCommon,
                 error_message = _("Multicast IP subnet is not supported "
                                   "if enable_dhcp is True")
                 raise exc.InvalidInput(error_message=error_message)
-            elif net.is_loopback():
+            if net.is_loopback():
                 error_message = _("Loopback IP subnet is not supported "
                                   "if enable_dhcp is True")
                 raise exc.InvalidInput(error_message=error_message)
-            elif ip_ver == constants.IP_VERSION_4 and net.first == 0:
+            if ip_ver == constants.IP_VERSION_4 and net.first == 0:
                 error_message = _("First IP '0.0.0.0' of network is not "
                                   "supported if enable_dhcp is True.")
                 raise exc.InvalidInput(error_message=error_message)
@@ -1636,7 +1638,7 @@ class NeutronDbPluginV2(db_base_plugin_common.DbBasePluginCommon,
                 return {'prefixes': subnetpool.prefixes}
 
             all_prefix_set = netaddr.IPSet(subnetpool.prefixes)
-            removal_prefix_set = netaddr.IPSet([x for x in prefixes])
+            removal_prefix_set = netaddr.IPSet(list(prefixes))
             if all_prefix_set.isdisjoint(removal_prefix_set):
                 # The prefixes requested for removal are not in the prefix
                 # list making this a no-op, so simply return.

neutron/db/l3_db.py

@@ -637,7 +637,7 @@ class L3_NAT_dbonly_mixin(l3.RouterPluginBase,
             msg = _('Router port must have at least one fixed IP')
             raise n_exc.BadRequest(resource='router', msg=msg)
 
-        fixed_ips = [ip for ip in port['fixed_ips']]
+        fixed_ips = list(port['fixed_ips'])
         for fixed_ip in fixed_ips:
             subnet = self._core_plugin.get_subnet(
                 context, fixed_ip['subnet_id'])
@@ -684,7 +684,7 @@ class L3_NAT_dbonly_mixin(l3.RouterPluginBase,
                             'p': existing_port['id'],
                             'nid': existing_port['network_id']})
 
-            fixed_ips = [ip for ip in port['fixed_ips']]
+            fixed_ips = list(port['fixed_ips'])
             subnets = []
             for fixed_ip in fixed_ips:
                 subnet = self._core_plugin.get_subnet(context,

neutron/db/migration/autogen.py

@@ -23,9 +23,7 @@ _ec_dispatcher = Dispatcher()
 
 
 def process_revision_directives(context, revision, directives):
-    directives[:] = [
-        directive for directive in _assign_directives(context, directives)
-    ]
+    directives[:] = list(_assign_directives(context, directives))
 
 
 def _assign_directives(context, directives, phase=None):
@@ -59,10 +57,9 @@ def _migration_script_ops(context, directive, phase):
 
     op = ops.MigrationScript(
         new_rev_id(),
-        ops.UpgradeOps(ops=[
-            d for d in _assign_directives(
-                context, directive.upgrade_ops.ops, phase)
-        ]),
+        ops.UpgradeOps(ops=list(
+            _assign_directives(context, directive.upgrade_ops.ops, phase)
+        )),
         ops.DowngradeOps(ops=[]),
         message=directive.message,
         **autogen_kwargs
@@ -116,9 +113,7 @@ def _alter_column(context, directive, phase):
 def _modify_table_ops(context, directive, phase):
     op = ops.ModifyTableOps(
         directive.table_name,
-        ops=[
-            d for d in _assign_directives(context, directive.ops, phase)
-        ],
+        ops=list(_assign_directives(context, directive.ops, phase)),
         schema=directive.schema)
     if not op.is_empty():
         return op

neutron/db/securitygroups_db.py

@@ -515,7 +515,7 @@ class SecurityGroupDbMixin(ext_sg.SecurityGroupPluginBase,
                 ip_proto in const.SG_PORT_PROTO_NAMES):
             if rule['port_range_min'] == 0 or rule['port_range_max'] == 0:
                 raise ext_sg.SecurityGroupInvalidPortValue(port=0)
-            elif (rule['port_range_min'] is not None and
+            if (rule['port_range_min'] is not None and
                     rule['port_range_max'] is not None and
                     rule['port_range_min'] <= rule['port_range_max']):
                 # When min/max are the same it is just a single port

neutron/ipam/drivers/neutrondb_ipam/driver.py

@@ -209,7 +209,6 @@ class NeutronDbSubnet(ipam_base.Subnet):
 
             if window < allocated_num_addresses:
                 continue
-            else:
             # Maximize randomness by using the random module's built in
             # sampling function
             av_ips = list(itertools.islice(av_set, 0, window))

neutron/objects/__init__.py

@@ -16,6 +16,7 @@ import sys
 
 def register_objects():
     # local import to avoid circular import failure
+    # pylint: disable=import-outside-toplevel
     from neutron.common import utils
     dirn = os.path.dirname(sys.modules[__name__].__file__)
     utils.import_modules_recursively(dirn)

neutron/objects/network_segment_range.py

@@ -148,8 +148,7 @@ class NetworkSegmentRange(base.NeutronDbObject):
                 .filter(
                     segments_model.NetworkSegment.network_id ==
                     models_v2.Network.id)).all()
-        return {segmentation_id: project_id
-                for segmentation_id, project_id in alloc_used}
+        return dict(alloc_used)
 
     @classmethod
     def _build_query_segments(cls, context, model, network_type, **filters):

neutron/objects/qos/qos_policy_validator.py

@@ -28,7 +28,7 @@ def check_bandwidth_rule_conflict(policy, rule_data):
         if rule.rule_type == qos_consts.RULE_TYPE_DSCP_MARKING:
             # Skip checks if Rule is DSCP
             continue
-        elif rule.rule_type == qos_consts.RULE_TYPE_MINIMUM_BANDWIDTH:
+        if rule.rule_type == qos_consts.RULE_TYPE_MINIMUM_BANDWIDTH:
             if "max_kbps" in rule_data and (
                     int(rule.min_kbps) > int(rule_data["max_kbps"])):
                 raise qos_exc.QoSRuleParameterConflict(

neutron/objects/router.py

@@ -124,7 +124,7 @@ class RouterExtraAttributes(base.NeutronDbObject):
         query = (context.session.query(l3.Router, sub_query.c.count).
                  outerjoin(sub_query))
 
-        return [(router, agent_count) for router, agent_count in query]
+        return list(query)
 
 
 @base.NeutronObjectRegistry.register

neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py

@@ -1876,7 +1876,7 @@ class OVNClient(object):
                 port, subnet['ip_version'])
             if lsp_dhcp_disabled:
                 continue
-            elif not lsp_dhcp_opts:
+            if not lsp_dhcp_opts:
                 lsp_dhcp_options = subnet_dhcp_option
             else:
                 port_dhcp_options = copy.deepcopy(dhcp_options)

neutron/plugins/ml2/managers.py

@@ -238,7 +238,7 @@ class TypeManager(stevedore.named.NamedExtensionManager):
         if network_type != constants.TYPE_VLAN:
             msg = (_('Only VLAN type networks can be updated.'))
             raise exc.InvalidInput(error_message=msg)
-        elif not segmentation_id:
+        if not segmentation_id:
             msg = (_('Only %s field can be updated in VLAN type networks') %
                    api.SEGMENTATION_ID)
             raise exc.InvalidInput(error_message=msg)

neutron/plugins/ml2/plugin.py

@@ -1597,7 +1597,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         if self._check_update_has_allowed_address_pairs(port):
             #  has address pairs in request
             raise addr_exc.AddressPairAndPortSecurityRequired()
-        elif not self._check_update_deletes_allowed_address_pairs(port):
+        if not self._check_update_deletes_allowed_address_pairs(port):
             # not a request for deleting the address-pairs
             updated_port[addr_apidef.ADDRESS_PAIRS] = (
                     self.get_allowed_address_pairs(context, id))
@@ -1611,7 +1611,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         # security groups, port security is set
         if self._check_update_has_security_groups(port):
             raise psec_exc.PortSecurityAndIPRequiredForSecurityGroups()
-        elif not self._check_update_deletes_security_groups(port):
+        if not self._check_update_deletes_security_groups(port):
             if not extensions.is_extension_supported(self, 'security-group'):
                 return
             # Update did not have security groups passed in. Check

neutron/privileged/agent/linux/ip_lib.py

@@ -245,7 +245,6 @@ def get_link_id(device, namespace, raise_exception=True):
     if not link_id or len(link_id) < 1:
         if raise_exception:
             raise NetworkInterfaceNotFound(device=device, namespace=namespace)
-        else:
         LOG.debug('Interface %(dev)s not found in namespace %(namespace)s',
                   {'dev': device, 'namespace': namespace})
         return None
@@ -640,9 +639,8 @@ def list_ip_rules(namespace, ip_version, match=None, **kwargs):
                 family=_IP_VERSION_FAMILY_MAP[ip_version],
                 match=match, **kwargs))
             for rule in rules:
-                rule['attrs'] = {
-                    key: value for key, value
-                    in ((item[0], item[1]) for item in rule['attrs'])}
+                rule['attrs'] = dict(
+                    (item[0], item[1]) for item in rule['attrs'])
             return rules
 
     except OSError as e:

neutron/services/conntrack_helper/plugin.py

@@ -117,7 +117,7 @@ class Plugin(l3_conntrack_helper.ConntrackHelperPluginBase):
     def _check_conntrack_helper_constraints(self, cth_obj):
         if cth_obj.helper not in self.constraints:
             raise cth_exc.ConntrackHelperNotAllowed(helper=cth_obj.helper)
-        elif cth_obj.protocol not in self.constraints[cth_obj.helper]:
+        if cth_obj.protocol not in self.constraints[cth_obj.helper]:
             raise cth_exc.InvalidProtocolForHelper(
                 helper=cth_obj.helper, protocol=cth_obj.protocol,
                 supported_protocols=', '.join(

neutron/services/logapi/drivers/base.py

@@ -50,6 +50,7 @@ class DriverBase(object):
     # the log driver.
     @registry.receives(log_const.LOGGING_PLUGIN, [events.AFTER_INIT])
     def _register(self, resource, event, trigger, payload=None):
+        # pylint: disable=using-constant-test
         if self.is_loaded:
             # trigger is the LoggingServiceDriverManager
             trigger.register_driver(self)

neutron/services/logapi/drivers/openvswitch/ovs_firewall_log.py

@@ -49,6 +49,7 @@ REMOTE_RULE_PRIORITY = 70
 def setup_logging():
     log_file = cfg.CONF.network_log.local_output_log_base
     if log_file:
+        # pylint: disable=import-outside-toplevel
         from logging import handlers as watch_handler
         log_file_handler = watch_handler.WatchedFileHandler(log_file)
         log_file_handler.setLevel(

neutron/services/qos/drivers/ovn/driver.py

@@ -55,6 +55,8 @@ class OVNQosDriver(base.DriverBase):
 
     @property
     def is_loaded(self):
+        # TODO(bcafarel): should be fixed in DriverBase in neutron-lib
+        # pylint:disable=invalid-overridden-method
         return OVN_QOS in cfg.CONF.ml2.extension_drivers
 
     def update_policy(self, context, policy):

neutron/services/trunk/plugin.py

@@ -85,7 +85,7 @@ class TrunkPlugin(service_base.ServicePluginBase):
             for port in ports:
                 subports[port['id']]['mac_address'] = port['mac_address']
             trunk_details = {'trunk_id': port_db.trunk_port.id,
-                             'sub_ports': [x for x in subports.values()]}
+                             'sub_ports': list(subports.values())}
             port_res['trunk_details'] = trunk_details
 
         return port_res
@@ -318,7 +318,6 @@ class TrunkPlugin(service_base.ServicePluginBase):
             # back to ACTIVE or ERROR.
             if trunk.status == constants.TRUNK_ERROR_STATUS:
                 raise trunk_exc.TrunkInErrorState(trunk_id=trunk_id)
-            else:
             trunk.update(status=constants.TRUNK_DOWN_STATUS)
 
             for subport in subports:

neutron/services/trunk/rpc/server.py

@@ -111,7 +111,6 @@ class TrunkSkeleton(object):
                 if try_cnt < db_api.MAX_RETRIES - 1:
                     LOG.debug("Got StaleDataError exception: %s", e)
                     continue
-                else:
                 # re-raise when all tries failed
                 raise
 

neutron/services/trunk/rules.py

@@ -132,7 +132,7 @@ class TrunkPortValidator(object):
         ]
         if len(drivers) > 1:
             raise trunk_exc.TrunkPluginDriverConflict()
-        elif len(drivers) == 1:
+        if len(drivers) == 1:
             return drivers[0].can_trunk_bound_port
         else:
             return False

test-requirements.txt

@@ -15,10 +15,8 @@ oslotest>=3.2.0 # Apache-2.0
 stestr>=1.0.0 # Apache-2.0
 reno>=3.1.0 # Apache-2.0
 ddt>=1.0.1 # MIT
-astroid==1.6.5;python_version<"3.0" # LGPLv2.1
-astroid==2.1.0;python_version>="3.0" # LGPLv2.1
-pylint==1.9.2;python_version<"3.0" # GPLv2
-pylint==2.2.0;python_version>="3.0" # GPLv2
+astroid==2.3.3 # LGPLv2.1
+pylint==2.4.4 # GPLv2
 isort==4.3.21 # MIT
 # Needed to run DB commands in virtualenvs
 PyMySQL>=0.7.6 # MIT License