asyncio init/close db pool.

Закрытие и init асинхронных драйверов ДБ

def init_app(loop):
....
    app.on_startup.append(init_db)
    app.on_cleanup.append(close_db)
...

async def init_db(app):
    """On startup initial"""
    async def init_mysql(database_conf, db_name):
        try:
            with async_timeout.timeout(2):
                mysql_db = await aiomysql.create_pool(**database_conf, loop=app.loop, autocommit=True)
                app[db_name] = mysql_db
                log.server_logger.info('Successful created pool for %s' % db_name)
        except Exception as e:
            log.server_logger.debug(e)

    async def init_postgres(database_conf, db_name):
        # import aiopg
        try:
            with async_timeout.timeout(2):
                pg_db = await aiopg.create_pool(**database_conf)
                app[db_name] = pg_db
                log.server_logger.info('Successful created pool for %s.\n'
                                       'Pool object - %s' % (db_name, pg_db))
        except Exception as e:
            log.server_logger.debug(e)

    await init_mysql(app['asterisk_cdr_conf'], db_name='asterisk_cdr')
    await init_mysql(app['asterisk_users_conf'], db_name='asterisk_users')


async def close_db(app):
    """On app shutdown"""
    async def close(database, db_name):
        if database:
            try:
                database.close()
            except (AttributeError, KeyError) as e:
                log.server_logger.info('The %s database was not initialized' % db_name)
                print('The %s database was not initialized' % db_name)
                return web.HTTPServiceUnavailable(text='The %s database was not initialized' % db_name)

            await database.wait_closed()
            log.server_logger.info('Database %s successfully closed' % db_name)
            print('Database %s successfully closed' % db_name)

        else:
            log.server_logger.debug('Empty %s database object' % db_name)
            print('Empty %s database object' % db_name)

    await close(app.get('asterisk_cdr', None), db_name='asterisk_cdr')
    await close(app.get('asterisk_users', None), db_name='asterisk_users')