Serverless Telegram bot on AWS Lambda and Python 3 In this article, I’ll show you how to create simple echo bot on webhooks written in Python 3 and deploy it to Lambda using Serverless framework. Telegram AWS My name is Andrii Dvoiak and I’m a team lead and full-stack engineer at . preply.com We are already using AWS Lambda in production so I decided to show how simple and hustle-free it can be. Relax, sit back and enjoy. Here is a plan Setup Serverles framework Get AWS credentials Write backend of Telegram Bot on Python 3 Deploy backend to Lambda Connect your backend to Telegram Bot Go live Before we start In order to go through this tutorial, make sure you have: Installed Python 3 Installed Node.js or later v6.5.0 AWS account with admin rights ( ) You can create one for free right here Step 1: Serverless framework Let’s start from the beginning. In order to easily write and deploy our lambda we will use this awesome framework called . It’s written on NodeJS so we need to install it. Let’s go: Serverless npm npm install -g serverless After this, let’s create a new project from template: serverless create --template aws-python3 --path my-telegram-bot It will create a new folder with two files: my-telegram-bot — a template for your Python code handler.py — configuration file serverless.yml Step 2: AWS Credentials This is the best part of this process, because once you’ve got credentials, you’ll never deal with AWS again. It’s super easy: Log in to your AWS Console, go to My Security Credentials > User and click on “Add User” blue button. Specify username (something like “serverless-admin”) and choose only “Programmatic access” checkbox. On the second page, choose “Attach existing policies directly” and look for “Administrator Access”. Once you created the user, copy your “Access key ID” and “Secret access key”. This is what you actually need to continue. Congrats. You’ve got your keys. Open your terminal and execute: export AWS_ACCESS_KEY_ID=<Access key ID> export AWS_SECRET_ACCESS_KEY=<Secret access key> Step 3: Write Telegram Bot on Python 3 I’m not going to teach you how to write in Python, so just copy this code and paste to your ` ` file: handler.py json os sys import import import here = os.path.dirname(os.path.realpath(__file__))sys.path.append(os.path.join(here, "./vendored")) requests import TOKEN = os.environ['TELEGRAM_TOKEN']BASE_URL = "https://api.telegram.org/bot{}".format(TOKEN) (event, context): :data = json.loads(event["body"])message = str(data["message"]["text"])chat_id = data["message"]["chat"]["id"]first_name = data["message"]["chat"]["first_name"] def hello try response = "Please /start, {}".format(first\_name) **if** "start" **in** message: response = "Hello {}".format(first\_name) data = {"text": response.encode("utf8"), "chat\_id": chat\_id} url = BASE\_URL + "/sendMessage" requests.post(url, data) **except** Exception **as** e: **print**(e) **return** {"statusCode": 200} If you are lazy enought, just fork or clone it from my GitHub . repo Also, you will need to create file with only one line: “requests” and execute this command to install it locally: requirements.txt pip install -r requirements.txt -t vendored Step 4: Deploy to AWS Lambda Pretty much like on Heroku, all you need is one configuration file “serverless.yml”. Go ahead and edit yours to make it look like this: my-telegram-bot service: aws python3.6 dev us-east-1 ${env:TELEGRAM_TOKEN} provider:name: runtime: stage: region: environment:TELEGRAM_TOKEN: handler.hello - my-custom-url post true functions:post:handler: events: http:path: method: cors: And the magic happens once you execute this in your terminal: serverless deploy It will pack all your files into .zip archive and upload to AWS, then it will create AWS API Gateway and return API endpoint for you. You will receive something like this: endpoints: POST - https://u3ir5tjcsf.execute-api.us-east-1.amazonaws.com/dev/my-custom-url The serverless backend of your bot is ready to use. You will need this URL on the next step. Step 5: Connect your backend to Telegram Bot Lets create new Telegram Bot, using, of course, another bot for this. Go to and write to this guy . He will guide you through the process and you will end up with something like this: web.telegram.org @BotFather Use this token to access the HTTP API: 459903168:APHruyw7ZFj5qOJmJGeYEmfFJxil-z5uLS8 First of all, set this as your environment variable: export TELEGRAM_TOKEN=" " 459903168:APHruyw7ZFj5qOJmJGeYEmfFJxil-z5uLS8 Then, we need set up webhook (register API url of your backend). To do this, you need t send this payload : {"url": "<Your API Gateway endpoint>"} to this url: https://api.telegram.org/bot<Your Telegram TOKEN>/setWebhook go to your terminal again and execute this line (put your url and TOKEN): curl --request POST --url --header 'content-type: application/json' --data '{"url": "https://u3ir5tjcsf.execute-api.us-east-1.amazonaws.com/dev/my-custom-url"}' https://api.telegram.org/bot 459903168:[APHruyw7ZFj5qOJmJGeYEmfFJxil-z5uLS8](https://api.telegram.org/botAPHruyw7ZFj5qOJmJGeYEmfFJxil-z5uLS8/setWebhook) /setWebhook If you did everything correct, you will receive something like this: {"ok": true,"result": true,"description": "Webhook was set"} Step 6: Go live We are almost done, lets just deploy it one more time to propagate your secret telegram token into lambda: serverless deploy Now it’s live! Congratulations. You can start chatting with your bot. P.S. Don’t forget to save all exported variables somewhere in ~/.bash_profile Never commit any api keys to your repository At the begining it will cost you nothing, because AWS Lambda has free tier of 100 000 invocations per month and API Gateway gives you 1 million API calls per month for free You can fork this example from GitHub repository You can find a planty examples of lambdas right here Conclusion Serverless approach is very convenient in some cases because it allows you to build very scalable solution. It also change your thinking paradigm about managing and paying for servers. Serverless framework gives you very simple tool to deploy your function with no need to know AWS or any other cloud provider. AWS gives you nice free tier period for services so you can build your MVPs totally for free, go live and start paying only if you reach a certain amount of users. What’s next The next article will write about chaining multiple lambdas using AWS Step Functions and connecting it to AWS DynamoDB.
