nocdnbs/app.py

from flask import Flask, render_template, request

from urllib.request import urlopen

app = Flask(__name__)

@app.route('/')
def home():
    domain = request.url_root
    return render_template('index.html', domain=domain)

@app.route('/<path:url>')
def proxy(url):
    jsdelivr_url = f'https://cdnjs.cloudflare.com/{url}'

    response = urlopen(jsdelivr_url)
    content = response.read()

    return content

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