Fix locking in migration tests

The migration test code included an external lock with a hard-coded
relative path that breaks when run in Jenkins.  It wasn't being hit
in Oslo because it was only locking for the postgres code path,
which isn't currently tested in Oslo.

This change moves the lock so that it applies to all db types and
removes the relative path.  For the locks to work properly it was
also necessary to add the lockutils wrapper to the Oslo tox.ini.

Closes-Bug: 1255608
Change-Id: I333b833022f208e48e3b7e82e8cfad2764be5ea0

openstack/common/db/sqlalchemy/test_migrations.py

@@ -164,7 +164,6 @@ class BaseMigrationTestCase(test.BaseTestCase):
         self.assertEqual('', err,
                          "Failed to run: %s\n%s" % (cmd, output))
 
-    @_set_db_lock('pgadmin', 'tests-')
     def _reset_pg(self, conn_pieces):
         (user, password, database, host) = get_db_connection_info(conn_pieces)
         os.environ['PGPASSWORD'] = password
@@ -186,6 +185,7 @@ class BaseMigrationTestCase(test.BaseTestCase):
         os.unsetenv('PGPASSWORD')
         os.unsetenv('PGUSER')
 
+    @_set_db_lock(lock_prefix='migration_tests-')
     def _reset_databases(self):
         for key, engine in self.engines.items():
             conn_string = self.test_databases[key]

tox.ini

@@ -12,7 +12,8 @@ deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands =
   # due to dependencies between tests (bug 1192207) we use `--concurrency=1` option
-  python setup.py test --slowest --testr-args='--concurrency=1 {posargs}'
+  # Use the lockutils wrapper to ensure that external locking works correctly
+  python -m openstack.common.lockutils python setup.py test --slowest --testr-args='--concurrency=1 {posargs}'
   {toxinidir}/tools/config/generate_sample.sh -p openstack
 
 [flake8]
@@ -32,7 +33,8 @@ commands = python ./tools/lint.py ./openstack
 setenv = VIRTUAL_ENV={envdir}
 commands =
   # due to dependencies between tests (bug 1192207) we use `--concurrency=1` option
-  python setup.py test --coverage --testr-args='--concurrency=1 {posargs}'
+  # Use the lockutils wrapper to ensure that external locking works correctly
+  python -m openstack.common.lockutils python setup.py test --coverage --testr-args='--concurrency=1 {posargs}'
 
 [testenv:venv]
 commands = {posargs}