Sync db.sqlalchemy from oslo-incubator

This updates db.sqlalchemy from oslo-incubator from hash
6f3e5a57aea5402031c4cc8863e0e35f7f222794

 $ python update.py --nodeps --base keystone \
    --dest-dir ../keystone --modules db.sqlalchemy

Change-Id: I2c8c104b6116f3f0cf0f17df196924ab7c20e072

keystone/openstack/common/db/sqlalchemy/models.py

@@ -59,7 +59,16 @@ class ModelBase(object):
     def get(self, key, default=None):
         return getattr(self, key, default)
 
-    def _get_extra_keys(self):
+    @property
+    def _extra_keys(self):
+        """Specifies custom fields
+
+        Subclasses can override this property to return a list
+        of custom fields that should be included in their dict
+        representation.
+
+        For reference check tests/db/sqlalchemy/test_models.py
+        """
         return []
 
     def __iter__(self):
@@ -67,7 +76,7 @@ class ModelBase(object):
         # NOTE(russellb): Allow models to specify other keys that can be looked
         # up, beyond the actual db columns.  An example would be the 'name'
         # property for an Instance.
-        columns.extend(self._get_extra_keys())
+        columns.extend(self._extra_keys)
         self._i = iter(columns)
         return self
 
@@ -89,7 +98,7 @@ class ModelBase(object):
         joined = dict([(k, v) for k, v in six.iteritems(self.__dict__)
                       if not k[0] == '_'])
         local.update(joined)
-        return local.iteritems()
+        return six.iteritems(local)
 
 
 class TimestampMixin(object):

keystone/openstack/common/db/sqlalchemy/session.py

@@ -289,7 +289,9 @@ database_opts = [
                deprecated_opts=[cfg.DeprecatedOpt('sql_idle_timeout',
                                                   group='DEFAULT'),
                                 cfg.DeprecatedOpt('sql_idle_timeout',
-                                                  group='DATABASE')],
+                                                  group='DATABASE'),
+                                cfg.DeprecatedOpt('idle_timeout',
+                                                  group='sql')],
                help='timeout before idle sql connections are reaped'),
     cfg.IntOpt('min_pool_size',
                default=1,
@@ -601,18 +603,24 @@ def _thread_yield(dbapi_con, con_record):
     time.sleep(0)
 
 
-def _ping_listener(dbapi_conn, connection_rec, connection_proxy):
-    """Ensures that MySQL connections checked out of the pool are alive.
+def _ping_listener(engine, dbapi_conn, connection_rec, connection_proxy):
+    """Ensures that MySQL and DB2 connections are alive.
 
     Borrowed from:
     http://groups.google.com/group/sqlalchemy/msg/a4ce563d802c929f
     """
+    cursor = dbapi_conn.cursor()
     try:
-        dbapi_conn.cursor().execute('select 1')
-    except dbapi_conn.OperationalError as ex:
-        if ex.args[0] in (2006, 2013, 2014, 2045, 2055):
-            LOG.warning(_('Got mysql server has gone away: %s'), ex)
-            raise sqla_exc.DisconnectionError("Database server went away")
+        ping_sql = 'select 1'
+        if engine.name == 'ibm_db_sa':
+            # DB2 requires a table expression
+            ping_sql = 'select 1 from (values (1)) AS t1'
+        cursor.execute(ping_sql)
+    except Exception as ex:
+        if engine.dialect.is_disconnect(ex, dbapi_conn, cursor):
+            msg = _('Database server has gone away: %s') % ex
+            LOG.warning(msg)
+            raise sqla_exc.DisconnectionError(msg)
         else:
             raise
 
@@ -670,8 +678,9 @@ def create_engine(sql_connection, sqlite_fk=False):
 
     sqlalchemy.event.listen(engine, 'checkin', _thread_yield)
 
-    if 'mysql' in connection_dict.drivername:
-        sqlalchemy.event.listen(engine, 'checkout', _ping_listener)
+    if engine.name in ['mysql', 'ibm_db_sa']:
+        callback = functools.partial(_ping_listener, engine)
+        sqlalchemy.event.listen(engine, 'checkout', callback)
     elif 'sqlite' in connection_dict.drivername:
         if not CONF.sqlite_synchronous:
             sqlalchemy.event.listen(engine, 'connect',

keystone/openstack/common/db/sqlalchemy/test_migrations.py

@@ -23,7 +23,7 @@ import lockfile
 import sqlalchemy
 import sqlalchemy.exc
 
-from keystone.openstack.common.gettextutils import _
+from keystone.openstack.common.gettextutils import _  # noqa
 from keystone.openstack.common import log as logging
 from keystone.openstack.common.py3kcompat import urlutils
 from keystone.openstack.common import test

keystone/openstack/common/db/sqlalchemy/utils.py

@@ -133,9 +133,9 @@ def paginate_query(query, model, limit, sort_keys, marker=None,
 
         # Build up an array of sort criteria as in the docstring
         criteria_list = []
-        for i in range(0, len(sort_keys)):
+        for i in range(len(sort_keys)):
             crit_attrs = []
-            for j in range(0, i):
+            for j in range(i):
                 model_attr = getattr(model, sort_keys[j])
                 crit_attrs.append((model_attr == marker_values[j]))
 
@@ -215,9 +215,9 @@ def drop_unique_constraint(migrate_engine, table_name, uc_name, *columns,
     NullType with the correct column type.
 
     :param migrate_engine: sqlalchemy engine
-    :param table_name:     name of table that contains unique constraint.
-    :param uc_name:        name of unique constraint that will be dropped.
-    :param columns:        columns that are in unique constraint.
+    :param table_name:     name of table that contains uniq constraint.
+    :param uc_name:        name of uniq constraint that will be dropped.
+    :param columns:        columns that are in uniq constraint.
     :param col_name_col_instance:   contains pair column_name=column_instance.
                             column_instance is instance of Column. These params
                             are required only for columns that have unsupported