A Now v2 Node-Server Telegram bot for getting the temperature of a city, using Node.js and Express (based on https://scotch.io/tutorials/how-to-build-a-telegram-bot-using-nodejs-and-now)

index.js

var express = require("express");
var app = express();
var bodyParser = require("body-parser");
require("now-env")
const axios = require("axios");

let telegram_url = "https://api.telegram.org/bot" + process.env.TELEGRAM_API_TOKEN +"/sendMessage";
let openWeatherUrl = process.env.OPENWEATHER_API_URL;

app.use(bodyParser.json());
app.use(
  bodyParser.urlencoded({
    extended: true
  })
);

app.post("/start_bot", function(req, res) {
  const { message } = req.body;
  let reply = "Welcome to telegram weather bot";
  let city_check = message.text.toLowerCase().indexOf('/');
  if (message.text.toLowerCase().includes('hi')) {
    sendMessage(telegram_url, reply, message, res);
  } else if ((message.text.toLowerCase().includes('check')) && (city_check !== -1 )) {
    city = message.text.split('/')[1];
    get_forecast(city).then( response => {
      sendMessage(telegram_url, response, message, res)
    });
  } else {
    reply = "request not understood, please review and try again.";
    sendMessage(telegram_url, message, reply, res);
    return res.end();
  }
});

function sendMessage(url, reply, message, res) {
  axios.post(url, {
    chat_id: message.chat.id,
    text: reply
  }).then(response => {
    console.log("Message posted");
    res.end("ok");
  }).catch(error =>{
    console.log(error);
  });
}

function get_forecast(city){
  let new_url = openWeatherUrl + city+"&appid="+process.env.OPENWEATHER_API_KEY;
  return axios.get(new_url).then(response => {
    let temp = response.data.main.temp;
    //converts temperature from kelvin to celsuis
    temp = Math.round(temp - 273.15);
    let city_name = response.data.name;
    let resp = "It's "+temp+" degrees in "+city_name;
    return resp;
  }).catch(error => {
    console.log(error);
  });
}

app.listen(3000, function() {
  console.log('Telegram app listening on port 3000!')
})

now.json

{
  "version": 2,
  "builds": [
    { "src": "index.js", "use": "@now/node-server" }
  ],
  "env": {
    "OPENWEATHER_API_KEY": "YOUR_OPENWEATHER_API_KEY",
    "OPENWEATHER_API_URL": "http://api.openweathermap.org/data/2.5/weather?q=",
    "TELEGRAM_API_TOKEN": "YOUR_TELEGRAM_API_KEY"
  },
  "routes": [
    { "src": "^/(.*)", "dest": "/" }
  ]
}

package.json

{
  "name": "telegram-weather-bot",
  "description": "A telegram bot made for Now v2 to get the temperature of a city",
  "dependencies": {
    "axios": "^0.18.0",
    "body-parser": "^1.18.3",
    "express": "^4.16.4",
    "now-env": "^3.1.0"
  }
}