The 'environ['werkzeug.server.shutdown']' function is deprecated and will be removed in Werkzeug 2.1.

Hi. First let me thank you for this amazing library! It’s been really useful for me. I just wanted to let you know that I’m getting this warning when using jupyter_dash on Python 3.8. Not sure what it means.

/opt/conda/lib/python3.8/site-packages/jupyter_dash/jupyter_app.py:139: UserWarning:

The 'environ['werkzeug.server.shutdown']' function is deprecated and will be removed in Werkzeug 2.1.

Thanks!

[RobertJN64]

I did some digging into the werkzeug code, and noticed that if you run with make_server instead of flask you can call a server shutdown command. This worked much better for me than the recommended solution of killing processes, which is very janky.

I replaced super_run_server with a custom function based on dash’s run server function, but used make_server instead. He is the core part:

if host + ":" + str(port) in activeservers:
    activeservers[host + ":" + str(port)].shutdown()
s = make_server(host, port, dashapp.server, threaded=True)
t = threading.Thread(target=s.serve_forever)
t.start()
activeservers[host + ":" + str(port)] = s

The full code is in my fork: https://github.com/RobertJN64/jupyter-dash/blob/master/jupyter_dash/server_tools.py

If this is an acceptable fix, I can make a pull request.

[helmutcarter]

Having the same issue:

    del environ['werkzeug.server.shutdown']
KeyError: 'werkzeug.server.shutdown'