Update pylint

A previous patch [1] changed tox environments to use python3 by default,
which makes the pylint test fail.

This patch updates the pylint package version and fixes pylint errors.

[1] https://review.openstack.org/#/c/572948/

Change-Id: I93c4a0c6060960552cc914963f410188eac7f3f4

blazar/db/sqlalchemy/utils.py

@@ -161,7 +161,7 @@ def _merge_periods(reserved_periods, start_date, end_date, duration):
     """Merge periods if the interval is too narrow."""
     reserved_start = None
     reserved_end = None
-    previous = None
+    previous = []
     merged_reserved_periods = []
     for period in reserved_periods:
         if not reserved_start:

blazar/plugins/oshosts/host_plugin.py

@@ -776,8 +776,7 @@ class PhysicalHostMonitorPlugin(base.BaseMonitorPlugin,
             recovered_hosts = [host for host in unreservable_hosts
                                if host['id'] in active_hv_ids]
         except Exception as e:
-            LOG.exception('Skipping health check of host %s. %s',
-                          host['hypervisor_hostname'], str(e))
+            LOG.exception('Skipping health check. %s', str(e))
 
         return failed_hosts, recovered_hosts
 

blazar/tests/db/migration/__init__.py

@@ -571,8 +571,8 @@ class BaseWalkMigrationTestCase(BaseMigrationTestCase):
         # the previous (higher numbered) migration.
         if with_data:
             post_downgrade = getattr(
-                self, "_post_downgrade_%s" % next_version, None)
-            if post_downgrade:
+                self, "_post_downgrade_%s" % next_version, self._do_nothing)
+            if post_downgrade is not self._do_nothing:
                 post_downgrade(engine)
 
         return True
@@ -604,3 +604,11 @@ class BaseWalkMigrationTestCase(BaseMigrationTestCase):
             LOG.error("Failed to migrate to version %(version)s on engine "
                       "%(engine)s", {'version': version, 'engine': engine})
             raise
+
+    def _do_nothing(self, *args, **kwargs):
+        """Workaround for passing the pylint check.
+
+        NOTE(hiro-kobayashi): this method is used by the _migrate_down() to
+        prevent 'not-callable' error of the pylint checker.
+        """
+        pass

lower-constraints.txt

@@ -76,7 +76,7 @@ pycadf==2.7.0
 pyflakes==0.8.1
 Pygments==2.2.0
 pyinotify==0.9.6
-pylint==1.4.5
+pylint==1.9.1
 pyparsing==2.2.0
 python-dateutil==2.7.0
 python-editor==1.0.3

requirements.txt

@@ -6,7 +6,7 @@ pbr!=2.1.0,>=2.0.0 # Apache-2.0
 alembic>=0.8.10 # MIT
 Babel!=2.4.0,>=2.3.4 # BSD
 eventlet!=0.18.3,!=0.20.1,>=0.18.2 # MIT
-Flask!=0.11,<1.0,>=0.10 # BSD
+Flask!=0.11,>=0.10 # BSD
 iso8601>=0.1.11 # MIT
 keystonemiddleware>=4.17.0 # Apache-2.0
 kombu!=4.0.2,>=4.0.0 # BSD

test-requirements.txt

@@ -10,7 +10,7 @@ testrepository>=0.0.18 # Apache-2.0/BSD
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
 coverage!=4.4,>=4.0 # Apache-2.0
-pylint==1.4.5 # GPLv2
+pylint>=1.9.1 # GPLv2
 oslotest>=3.2.0 # Apache-2.0
 oslo.context>=2.19.2 # Apache-2.0