1dbf086aa9
File api.py: W402 'q_exc' imported but unused Change-Id: Ibe8fa9c3b3607165bcd30867ef0df71aea04806b
138 lines
4.2 KiB
Python
138 lines
4.2 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
|
# Copyright 2011 Nicira Networks, Inc.
|
|
# All Rights Reserved.
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
# @author: Somik Behera, Nicira Networks, Inc.
|
|
# @author: Brad Hall, Nicira Networks, Inc.
|
|
# @author: Dan Wendlandt, Nicira Networks, Inc.
|
|
|
|
import logging
|
|
import time
|
|
|
|
import sqlalchemy as sql
|
|
from sqlalchemy import create_engine
|
|
from sqlalchemy.exc import DisconnectionError
|
|
from sqlalchemy.orm import sessionmaker, exc
|
|
|
|
from quantum.db import model_base
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
_ENGINE = None
|
|
_MAKER = None
|
|
BASE = model_base.BASE
|
|
|
|
|
|
class MySQLPingListener(object):
|
|
|
|
"""
|
|
Ensures that MySQL connections checked out of the
|
|
pool are alive.
|
|
|
|
Borrowed from:
|
|
http://groups.google.com/group/sqlalchemy/msg/a4ce563d802c929f
|
|
"""
|
|
|
|
def checkout(self, dbapi_con, con_record, con_proxy):
|
|
try:
|
|
dbapi_con.cursor().execute('select 1')
|
|
except dbapi_con.OperationalError, ex:
|
|
if ex.args[0] in (2006, 2013, 2014, 2045, 2055):
|
|
LOG.warn('Got mysql server has gone away: %s', ex)
|
|
raise DisconnectionError("Database server went away")
|
|
else:
|
|
raise
|
|
|
|
|
|
def configure_db(options):
|
|
"""
|
|
Establish the database, create an engine if needed, and
|
|
register the models.
|
|
|
|
:param options: Mapping of configuration options
|
|
"""
|
|
global _ENGINE
|
|
if not _ENGINE:
|
|
connection_dict = sql.engine.url.make_url(options['sql_connection'])
|
|
engine_args = {
|
|
'pool_recycle': 3600,
|
|
'echo': False,
|
|
'convert_unicode': True,
|
|
}
|
|
|
|
if 'mysql' in connection_dict.drivername:
|
|
engine_args['listeners'] = [MySQLPingListener()]
|
|
|
|
_ENGINE = create_engine(options['sql_connection'], **engine_args)
|
|
base = options.get('base', BASE)
|
|
if not register_models(base):
|
|
if 'reconnect_interval' in options:
|
|
remaining = options.get('sql_max_retries', -1)
|
|
reconnect_interval = options['reconnect_interval']
|
|
retry_registration(remaining, reconnect_interval, base)
|
|
|
|
|
|
def clear_db(base=BASE):
|
|
global _ENGINE
|
|
assert _ENGINE
|
|
for table in reversed(base.metadata.sorted_tables):
|
|
_ENGINE.execute(table.delete())
|
|
|
|
|
|
def get_session(autocommit=True, expire_on_commit=False):
|
|
"""Helper method to grab session"""
|
|
global _MAKER, _ENGINE
|
|
if not _MAKER:
|
|
assert _ENGINE
|
|
_MAKER = sessionmaker(bind=_ENGINE,
|
|
autocommit=autocommit,
|
|
expire_on_commit=expire_on_commit)
|
|
return _MAKER()
|
|
|
|
|
|
def retry_registration(remaining, reconnect_interval, base=BASE):
|
|
if remaining == -1:
|
|
remaining = 'infinite'
|
|
while True:
|
|
if remaining != 'infinite':
|
|
if remaining == 0:
|
|
LOG.error("Database connection lost, exit...")
|
|
break
|
|
remaining -= 1
|
|
LOG.info("Unable to connect to database, %s attempts left. "
|
|
"Retrying in %s seconds" % (remaining, reconnect_interval))
|
|
time.sleep(reconnect_interval)
|
|
if register_models(base):
|
|
break
|
|
|
|
|
|
def register_models(base=BASE):
|
|
"""Register Models and create properties"""
|
|
global _ENGINE
|
|
assert _ENGINE
|
|
try:
|
|
base.metadata.create_all(_ENGINE)
|
|
except sql.exc.OperationalError as e:
|
|
LOG.info("Database registration exception: %s" % e)
|
|
return False
|
|
return True
|
|
|
|
|
|
def unregister_models(base=BASE):
|
|
"""Unregister Models, useful clearing out data before testing"""
|
|
global _ENGINE
|
|
assert _ENGINE
|
|
base.metadata.drop_all(_ENGINE)
|