Telegram bot を AWS API gateway + Lambda でやってみた

lambda_telegram_bot_sample.js

/*
https://qiita.com/leokryslov/items/35f98e8e24e797441150
が、そのままでは
- `event.message.text` じゃなく `event.body.message.text` だよね
- API Gatewayが"Malformed Lambda proxy response"とか吐いてた
ということで動くまで直したやつ。
*/

const https = require('https');

const BOT_TOKEN = process.env.BOT_TOKEN
const URL = "https://api.telegram.org/bot" + BOT_TOKEN + "/sendMessage?";

exports.handler = (event, context, callback) => {
    
    let response = {
        'statusCode': 200,
        'body': JSON.stringify(event)
    }
    
    var replyUrl = "";
    let event_body = "";
    try{
        event_body = JSON.parse(event.body);
    }catch(e){
        event_body = event.body;
    }
    let message = event_body.message;
    let text = 'Echo: ' + message.text;
    let chatId = message.chat.id;
    replyUrl = URL + 'text=' + text + '&chat_id=' + chatId;
    
    https.get(replyUrl, (res) => {
        console.log("Got response: " + res.statusCode);
        response.statusCode = 200;
        callback(null, response);

    }).on('error', (e) => {
        console.log("Got error: " + e.message);
        response.statusCode = 502;
        callback(Error(e));

    })
};

動くことは確認できたのであとは telegraf.js でやる。