tornado asyncio docker graceful shutdown

def sig_handler(sig, frame):
    io_loop = tornado.ioloop.IOLoop.instance()
    
    def stop_loop():
        if len(asyncio.Task.all_tasks(io_loop)) == 0:
            io_loop.stop()
        else:
            io_loop.call_later(1, stop_loop)

    io_loop.add_callback_from_signal(stop_loop)
    
    
serv():
    tornado.platform.asyncio.AsyncIOMainLoop().install()
    
    ....
    
    signal.signal(signal.SIGTERM, partial(sig_handler))
    asyncio.get_event_loop().run_forever()

Thanks to @wonderbeyond for the more complete example at https://gist.github.com/wonderbeyond/d38cd85243befe863cdde54b84505784