Run Python code via cPanel without restarting or timing out, and also use Flask

cpanel_wsgi_template.py

import os
import json
import html
import signal
from datetime import datetime
from flask import Flask, render_template, request, jsonify

# Check if `signal.alarm` is supported
signal_supported = hasattr(signal, 'SIGALRM')
if signal_supported:
    class TimeoutException(Exception):
        pass

    def timeout_handler(signum, frame):
        raise TimeoutException("Request took too long!")

    # Register the timeout signal handler
    signal.signal(signal.SIGALRM, timeout_handler)

# Edit this part - start
template_folder = 'public_html/example'
template_file = 'index.html'
# Edit this part - end
app = Flask(__name__, 
    template_folder=template_folder,
    static_folder=template_folder + '/static')

@app.route('/', methods=['GET', 'POST'])
def flaskFormProccessing():
    if __name__ == '__main__' and request.method == 'GET':
        try:
            return render_template(template_file)
        except Exception as e:
            print(str(e))
    # Edit this part - start
    # Process the form nomally with Flask, for example firstName = request.form.get('first-name') and return jsonify({'key1': value2, 'key2': value2})
    pass
    # Edit this part - end

# This is the only function that gets loaded initially so everything goes through here first
def application(environ, start_response):
    # Before anything else, get the app restarted automatically to support any code changes
    restart_file = os.path.join(os.path.dirname(__file__), 'tmp/restart.txt')
    if os.path.exists(restart_file):
      current_time = datetime.now().timestamp()
      os.utime(restart_file, (current_time, current_time))

    # Set a realistic timeout instead of relying on the server's timeout
    if signal_supported:
      signal.alarm(30)
    try:
      # Avoid waiting indefinitely (or until a timeout) if a form was submitted without fields
      content_length = int(environ.get('CONTENT_LENGTH', 0))
      if content_length == 0:
        # Just an example, as it depends on what your form expects - the example assumes the form uses Fetch API or Ajax
        start_response('200 OK', [('Content-Type', 'application/json')])
        return [json.dumps({'output': 'No form values passed', 'success': False}).encode()]
    
      # Instead of checking form fields with manual methods, just send to Flask
      with app.test_request_context(base_url=environ.get('wsgi.url_scheme', 'http') + '://' + environ.get('HTTP_HOST', ''), environ_overrides=environ):
          # Let Flask handle the request
          response = app.full_dispatch_request()
      # Convert Flask's response to WSGI response
      start_response(
          response.status,
          [(k, v) for k, v in response.headers]
      )
      return [response.get_data()]
    except TimeoutException:
        # Just an example, as it depends on what your form expects - the example assumes the form uses Fetch API or Ajax
        start_response('504 Gateway Timeout',  [('Content-Type', 'application/json')])
        return [json.dumps({'output': 'Request timed out', 'success': False}).encode()]
    except Exception as e:
        # Just an example, as it depends on what your form expects - the example assumes the form uses Fetch API or Ajax
        start_response('500 Internal Server Error', [('Content-Type', 'application/json')])
        return [json.dumps({'output': str(e), 'success': False}).encode()]
    finally:
        # The timer finished serving its purpose
        if signal_supported:
          signal.alarm(0)  # Disable the alarm

if __name__ == '__main__':
    # Only use debug mode when running locally
    is_production = os.environ.get('PRODUCTION', 'false').lower() == 'true'
    if is_production:
        app.run(host='0.0.0.0', port=int(os.environ.get('PORT', 8080)))
    else:
        app.run(debug=True)