def _raise_if_db_connection_lost(error, engine):
# NOTE(vsergeyev): Function is_disconnect(e, connection, cursor)
# requires connection and cursor in incoming parameters,
# but we have no possibility to create connection if DB
# is not available, so in such case reconnect fails.
# But is_disconnect() ignores these parameters, so it
# makes sense to pass to function None as placeholder
# instead of connection and cursor.
if engine.dialect.is_disconnect(error, None, None):
raise exception.DBConnectionError(error)
def _execute_sql(engine, sql, driver):
"""Initialize connection, execute sql query and close it."""
try:
with engine.connect() as conn:
if driver == 'postgresql':
conn.connection.set_isolation_level(0)
for s in sql:
conn.execute(s)
except sqlalchemy.exc.OperationalError:
msg = ('%s does not match database admin '
'credentials or database does not exist.')
raise exc.DBConnectionError(msg % SQL_CONNECTION)