async def shutdown(signal, loop):
    logging.info(f"Received exit signal {signal.name}...")
    logging.info("Closing database connections")
    logging.info("Nacking outstanding messages")
    tasks = [t for t in asyncio.all_tasks() if t is not
             asyncio.current_task()]

    [task.cancel() for task in tasks]

    logging.info(f"Cancelling {len(tasks)} outstanding tasks")
    await asyncio.gather(*tasks, return_exceptions=True)
    logging.info(f"Flushing metrics")
    loop.stop()

def add_signal_handler:
for s in signals:
    loop.add_signal_handler(s, lambda s=s: asyncio.create_task(shutdown(s, loop)))