Fix new pylint issues

new pylint 2.9.0 provides some new checkers and detects new errors with
existing checkers:
- consider-using-enumerate (disabled)
- consider-using-from-import
- arguments-renamed (disabled)
- consider-using-with
- consider-using-dict-items

Change-Id: I4651f8bdaca13486a1dc6408f445d41779a95653

.pylintrc

@@ -56,7 +56,9 @@ disable=
  multiple-statements,
  duplicate-except,
  keyword-arg-before-vararg,
- useless-object-inheritance
+ useless-object-inheritance,
+ arguments-renamed,
+ consider-using-enumerate
 
 [BASIC]
 # Variable names can be 1 to 31 characters long, with lowercase and underscores

octavia/amphorae/drivers/health/heartbeat_udp.py

@@ -520,17 +520,16 @@ class UpdateHealthDb:
                     session, db_pool_id, db_pool_dict, pools,
                     lb_status, processed_pools, potential_offline_pools)
 
-        for pool_id in potential_offline_pools:
+        for pool_id, pool in potential_offline_pools.items():
             # Skip if we eventually found a status for this pool
             if pool_id in processed_pools:
                 continue
             try:
                 # If the database doesn't already show the pool offline, update
-                if potential_offline_pools[pool_id] != constants.OFFLINE:
+                if pool != constants.OFFLINE:
                     self._update_status(
                         session, self.pool_repo, constants.POOL,
-                        pool_id, constants.OFFLINE,
-                        potential_offline_pools[pool_id])
+                        pool_id, constants.OFFLINE, pool)
             except sqlalchemy.orm.exc.NoResultFound:
                 LOG.error("Pool %s is not in DB", pool_id)
 

octavia/api/v2/controllers/listener.py

@@ -276,8 +276,8 @@ class ListenersController(base.BaseController):
             # new listener
             disallowed_protocols = [
                 p
-                for p in constants.L4_PROTOCOL_MAP
-                if constants.L4_PROTOCOL_MAP[p] == l4_protocol
+                for p, l4_p in constants.L4_PROTOCOL_MAP.items()
+                if l4_p == l4_protocol
             ]
 
             for db_l in db_listeners:

octavia/api/v2/controllers/load_balancer.py

@@ -37,7 +37,7 @@ from octavia.common import data_models
 from octavia.common import exceptions
 from octavia.common import stats
 from octavia.common import utils
-import octavia.common.validate as validate
+from octavia.common import validate
 from octavia.db import api as db_api
 from octavia.db import prepare as db_prepare
 from octavia.i18n import _

octavia/api/v2/controllers/member.py

@@ -29,7 +29,7 @@ from octavia.api.v2.types import member as member_types
 from octavia.common import constants
 from octavia.common import data_models
 from octavia.common import exceptions
-import octavia.common.validate as validate
+from octavia.common import validate
 from octavia.db import api as db_api
 from octavia.db import prepare as db_prepare
 

octavia/certificates/generator/local.py

@@ -45,7 +45,8 @@ class LocalCertGenerator(cert_gen.CertGenerator):
         if not ca_cert:
             LOG.info("Using CA Certificate from config.")
             try:
-                ca_cert = open(CONF.certificates.ca_certificate, 'rb').read()
+                with open(CONF.certificates.ca_certificate, 'rb') as fp:
+                    fp.read()
             except IOError as e:
                 raise exceptions.CertificateGenerationException(
                     msg="Failed to load CA Certificate {0}."
@@ -54,7 +55,8 @@ class LocalCertGenerator(cert_gen.CertGenerator):
         if not ca_key:
             LOG.info("Using CA Private Key from config.")
             try:
-                ca_key = open(CONF.certificates.ca_private_key, 'rb').read()
+                with open(CONF.certificates.ca_private_key, 'rb') as fp:
+                    fp.read()
             except IOError as e:
                 raise exceptions.CertificateGenerationException(
                     msg="Failed to load CA Private Key {0}."

octavia/common/data_models.py

@@ -30,10 +30,9 @@ class BaseDataModel(object):
         """Converts a data model to a dictionary."""
         calling_classes = calling_classes or []
         ret = {}
-        for attr in self.__dict__:
+        for attr, value in self.__dict__.items():
             if attr.startswith('_') or not kwargs.get(attr, True):
                 continue
-            value = self.__dict__[attr]
             if attr == 'tags':
                 # tags is a list, it doesn't need recurse
                 ret[attr] = value

octavia/controller/worker/v1/tasks/database_tasks.py

@@ -26,7 +26,7 @@ from taskflow.types import failure
 
 from octavia.common import constants
 from octavia.common import data_models
-import octavia.common.tls_utils.cert_parser as cert_parser
+from octavia.common.tls_utils import cert_parser
 from octavia.common import utils
 from octavia.controller.worker import task_utils as task_utilities
 from octavia.db import api as db_apis

octavia/controller/worker/v2/tasks/database_tasks.py

@@ -27,7 +27,7 @@ from taskflow.types import failure
 from octavia.api.drivers import utils as provider_utils
 from octavia.common import constants
 from octavia.common import data_models
-import octavia.common.tls_utils.cert_parser as cert_parser
+from octavia.common.tls_utils import cert_parser
 from octavia.common import utils
 from octavia.controller.worker import task_utils as task_utilities
 from octavia.db import api as db_apis