How to properly return http response from Python R

问题:

This question continues from here.

I want to create a reverse proxy of sorts that will allow me to host an application that runs on a specified port on a server that does not have that port open. But I do not want take over ports 80/443 because I need to have other apps running on that server. Instead, I want an app running at localhost:#### to be served from a suburl or subdomain such as http://myserver/myapp.

Here is what I tried:

helloflask.py

#!/usr/bin/env python

from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello_world():
    return 'Hello World!'

if __name__ == '__main__':
    app.run()

middle.py

#!/usr/bin/env python

print ("Content-Type: text/html")
print()

import requests
#response = requests.get("http://localhost:5000")
response = requests.get("http://localhost:8888/token=8a387fe88d662e2568f9b8ec2398191452492e7184536670")

print(response.text)

When I run helloflask.py it runs on port 5000, and I can visit mydomain/middle.py and get the correct response of "Hello World!" displayed in the browser.

However, when I run a jupyter notebook on port 8888, I get a malformed web page. Strangely, the page sources are identical (see the diff).

So, what do I need to do to make jupyter run from the proxy?

Here is an image of how the page appears through middle.py. The link to IPythonParallel works, but no other links or controls function in any way.