create proxy server on flask and requests python

FLASK-SERVER-PROXY

"""today am gonna show you how to create a http proxy in flask, if your want https ssl proxy please dope a email at info[at]junno[dot]co"""
"""and please make sure to follow me for more proxies server and more server gists"""
""" add the proxy url to firefox,chrome or any other browser eg(http://proxy_flask_address:proxy_flask_port5000)"""
"""remember on replit this works only on locally if you want it to work publically please purchase a server e.g(linode, digitalocean etc..)"""
"""curl -x  http://172.18.0.9:5000 -L http://azenv.net -vs >curl-output.txt 2>&1
"""SSL is the old name. It is called TLS these days."""
"""to use ssl add ssl_context='adhoc' to your app.run() call or $ flask run --cert=adhoc and then To use ad hoc certificates with Flask, you need to install an additional dependency in your virtual environment:
   $ pip install pyopenssl"""
import re
from urllib.parse import urlparse, urlunparse
from flask import Flask, render_template, request, abort, Response, redirect
import requests
import logging

app = Flask('')

@app.route('/', methods=["GET", "POST"])
def root():
    # If referred from a proxy request, then redirect to a URL with the proxy prefix.
    # This allows server-relative and protocol-relative URLs to work.
    referer = request.headers.get('referer')
    
    if not request.url:
        return Response("Relative URL sent without a a proxying request referal. Please specify a valid proxy host (/p/url)", 400)
    parts = None
    
    if request.url == "":
        parts = referer
        
    else:
        parts = request.url
        
        
        #return redirect(urlunparse(parts._replace(path=parts.path+'/')))
    r = make_request(part, request.method, dict(request.headers), request.form)
    headers = dict(r.raw.headers)
    h = filter_headers(headers)
    def generate():
        for chunk in r.raw.stream(decode_content=False):
            yield chunk
            
    out = app.response_class(generate(), headers=headers)
    print(out)
    out.status_code = r.status_code
    return out #(r.text, r.status_code, headers)

def filter_headers(headers):
        # http://tools.ietf.org/html/rfc2616#section-13.5.1
        hop_by_hop = ('Connection', 'Keep-Alive','Te', 'Trailers', 'Transfer-Encoding', 'Upgrade')
        for k in hop_by_hop:
            if k in headers:
               del headers[k]

        # accept only supported encodings
        if 'Accept-Encoding' in headers:
            ae = headers['Accept-Encoding']
            filtered_encodings = [x for x in re.split(r',\s*', ae) if x in ('identity', 'gzip', 'x-gzip', 'deflate')]
            headers['Accept-Encoding'] = ', '.join(filtered_encodings)

        return headers

def make_request(url, method, headers={}, data=None):
    # Ensure the URL is approved, else abort
    # Pass original Referer for subsequent resource requests
    try:
      referer = request.headers.get('referer')
      if referer:
        headers.update({ "referer" : url})

      # Fetch the URL, and stream it back
      LOG.debug("Sending %s %s with headers: %s and data %s", method, url, headers, data)
      return requests.request(method, url, params=request.args, stream=True, headers=headers, allow_redirects=False, data=data)
    except Exception as e:
        print(e)

def run():
    print('starting')
    app.run(host = '0.0.0.0', port = 5000)



def keep_alive():
    
    from threading import Thread
    t = Thread(target = run)
    t.start()

if __name__ == '__main__':
    run()