neutron/neutron/db/migration/alembic_migrations/env.py

109 lines
2.9 KiB
Python

# Copyright 2012 New Dream Network, LLC (DreamHost)
#
# 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.
from logging import config as logging_config
from alembic import context
from oslo.config import cfg
from oslo.db.sqlalchemy import session
import sqlalchemy as sa
from sqlalchemy import event
from neutron.db.migration.models import head # noqa
from neutron.db import model_base
MYSQL_ENGINE = None
# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config
neutron_config = config.neutron_config
# Interpret the config file for Python logging.
# This line sets up loggers basically.
logging_config.fileConfig(config.config_file_name)
# set the target for 'autogenerate' support
target_metadata = model_base.BASEV2.metadata
def set_mysql_engine():
try:
mysql_engine = neutron_config.command.mysql_engine
except cfg.NoSuchOptError:
mysql_engine = None
global MYSQL_ENGINE
MYSQL_ENGINE = (mysql_engine or
model_base.BASEV2.__table_args__['mysql_engine'])
def run_migrations_offline():
"""Run migrations in 'offline' mode.
This configures the context with either a URL
or an Engine.
Calls to context.execute() here emit the given string to the
script output.
"""
set_mysql_engine()
kwargs = dict()
if neutron_config.database.connection:
kwargs['url'] = neutron_config.database.connection
else:
kwargs['dialect_name'] = neutron_config.database.engine
context.configure(**kwargs)
with context.begin_transaction():
context.run_migrations()
@event.listens_for(sa.Table, 'after_parent_attach')
def set_storage_engine(target, parent):
if MYSQL_ENGINE:
target.kwargs['mysql_engine'] = MYSQL_ENGINE
def run_migrations_online():
"""Run migrations in 'online' mode.
In this scenario we need to create an Engine
and associate a connection with the context.
"""
set_mysql_engine()
engine = session.create_engine(neutron_config.database.connection)
connection = engine.connect()
context.configure(
connection=connection,
target_metadata=target_metadata
)
try:
with context.begin_transaction():
context.run_migrations()
finally:
connection.close()
if context.is_offline_mode():
run_migrations_offline()
else:
run_migrations_online()