使用 gevents Wsgi 服务器在进程中多次启动和停止烧瓶应用程序

Question

I have a flask app which I need to start and then shut down within the same process and repeat this multiple times. I am using gevents in my application so I'm using gevents.pywsgi as my WSGI server. Now I'm trying to gracefully shutdown the server so I can restart it in the same process after I do a few other things.

So the following code creates a basic flask app, which when receives a POST request with any valid data on /hit endpoint populates the data field. A greenlet is running in parallel with this app and when it sees that the data field is populated, it shuts down the server.

    def func():
    global data
    data = None

    app = Flask(__name__)

    @app.route('/hit', methods=['POST'])
    def hit():
        global data
        data = request.json

        if data is not None:
            return "Input Recieved, Server closed "
        else:
            return "Invalid Input, Try again"

    def shutdown_server(_server):
        global data
        while data is None:
            sleep(0.5)
        _server.stop()
        _server.close()

    server = WSGIServer(('0.0.0.0',5100), app)

    start = spawn(server.start)
    stop = spawn(shutdown_server, request, server)

    joinall([start, stop])

    return True

Now this code is running fine if I run the server once, but if I try to run the server again within the same process it throws the following error:

Traceback (most recent call last):
  File "src/gevent/greenlet.py", line 766, in gevent._greenlet.Greenlet.run
  File "/home/batman/Documents/genisys/lib/python3.6/site-packages/gevent/baseserver.py", line 308, in start
    self.start_accepting()
  File "/home/batman/Documents/genisys/lib/python3.6/site-packages/gevent/baseserver.py", line 160, in start_accepting
    self._watcher = self.loop.io(self.socket.fileno(), 1)
AttributeError: 'WSGIServer' object has no attribute 'socket'

I'm not sure if this is even possible, or if I have to run the server in a separate process if I want to run it multiple times. Can anybody tell me why I'm facing this error and is there a better and cleaner way to shutdown the server so I don't face this error?

EDIT : I give IP and port as arguments to func, so I have tried call func with a different port multiple times and with the same port multiple times, I still get the same error.

Answer 1

我认为问题是您已经在端口 5100 上运行服务器，因此您无法在同一端口上运行进程，因此您必须在启动进程时动态更改端口号