How to use telegram webhook on google cloud functions?

Question

I have set up a telegram bot using webhooks in python on google cloud functions. Based on some sample code from the internet I got it to work as a simple echo-bot however the structure is very different to the bots I coded before using long polling:

# main.py
import os
import telegram

def webhook(request):
    bot = telegram.Bot(token=os.environ["TELEGRAM_TOKEN"])
    if request.method == "POST":
        update = telegram.Update.de_json(request.get_json(force=True), bot)
        chat_id = update.message.chat.id
        # Reply with the same message
        bot.sendMessage(chat_id=chat_id, text=update.message.text)
    return "ok"

I do not understand how to add any more handlers or different functions to this, especially because cloud functions needs me to name only one function to run from the script (in this case the webhook function).

How can I convert the above logic to the one I am more familiar with below:

import os

TOKEN = "TOKEN"
PORT = int(os.environ.get('PORT', '8443'))
updater = Updater(TOKEN)

# add example handler

def start(update, context):
        context.bot.send_message(chat_id=update.message.chat_id, text="Hello, I am dice bot and I will roll some tasty dice for you.")

    start_handler = CommandHandler('start', start)
    dispatcher.add_handler(start_handler)

# start webhook polling

updater.start_webhook(listen="0.0.0.0",
                      port=PORT,
                      url_path=TOKEN)
updater.bot.set_webhook("https://<appname>.herokuapp.com/" + TOKEN)
updater.idle()

This code has the same structure as long polling so I know how to add additional handlers. However it has two problems:

1. It is the code snippet from the documentation for heroku, so I do not know whether this works the same for google cloud functions

2. This does not produce one function I can call in cloud functions, I tried wrapping all my code above in one big function webhook and simply running that but it does not work (and does not produce an error on my google dashboard).

Any help is appreciated!

Answer 1

i did that here's my snippet

from telegram import Bot,Update
from telegram.ext import CommandHandler,Dispatcher
import os

TOKEN = os.getenv('TOKEN')
bot = Bot(token=TOKEN)

dispatcher = Dispatcher(bot,None,workers=0)

def start(update,context):
  context.bot.send_message(chat_id=update.effective_chat.id,text="I am a bot, you can talk to me")


dispatcher.add_handler(CommandHandler('start',start))


def main(request):
  update = Update.de_json(request.get_json(force=True), bot)

  dispatcher.process_update(update)
  return "OK"

# below function to be used only once to set webhook url on telegram 
def set_webhook(request):
  global bot
  global TOKEN
  s = bot.setWebhook(f"{URL}/{TOKEN}") # replace your functions URL,TOKEN
  if s:
    return "Webhook Setup OK"
  else:
    return "Webhook Setup Failed"

Answer 2

I found this github telebot repo from yukuku with the setup of a telegram bot on App Engine and the webhook implementation using python. As mentioned before you may want to use App Engine in order to implement your bot with many functions on the same main.py file.

I just tried and it's working for me.