python - 如何检查python是否作为click cli命令而不是flask服务器运行？

Question

我有一个小型 Flask 服务器，它使用 click 来定义一些通过 cron 运行的命令。
我的服务器通过 asyncio & asynqp 连接到 Rabbitmq:

class RabbitMQConnection():
    def __init__(self):
        self.connection = None
        self.channel = None
        self.exchange = None

    @asyncio.coroutine
    def connect(self): 
        self.connection = yield from asynqp.connect(
            'rabbitmq-host',
            5672,
            username=RABBITMQ_USERNAME,
            password=RABBITMQ_PASSWORD)

class MessageProcessor(Thread):
    def run(self):
        loop = asyncio.new_event_loop()
        loop.create_task(self._run())
        loop.run_forever()

    @asyncio.coroutine
    def _run(self):
        rabbit = RabbitMQConnection()
        yield from rabbit.connect()


def init_app(app):
    thread = MessageProcessor()
    thread.daemon = True
    thread.start()

当我运行单击命令时，它会加载 Flask 应用程序(我想要它，因为它包含我的数据库模型)，但还会启动与 rabbitmq 的另一个连接。 如果我在单击命令的上下文中运行或仅作为 flask 服务器运行，我希望能够检查上述 init_app 函数。

以下是单击命令定义的示例:

@click.command('my-function')
@with_appcontext
def my_function():
    click.echo('this was fun')

def init_app(app):
    app.cli.add_command(my_function)

Answer 1

这有点黑客，但它对我有用:

# detect if we are running the app.
# otherwise we are running a custom flask command.
command_line = ' '.join(sys.argv)
is_running_server = ('flask run' in command_line) or ('gunicorn' in command_line)

if is_running_server:
  # do stuff that should only happen when running the server. 

参见: How do I access command line arguments?