DDRAE Telegram Bot

D ellos's D iccionario de la R eal A cademia E spañola Telegram Bot @ddrae_bot

A Telegram Bot which allows you to search Spanish word definitions in the official Spanish dictionary (Diccionario de la Real Academia Española (D.R.A.E)).

The deployed Heroku Node.js server is the following: https://ddrae-telegram-bot.herokuapp.com.

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Table of contents

• Screenshots
• How it was built
  • Used technologies
  • Create your own DDRAE Telegram Bot
    • Create your own Telegram Bot
    • Set up your DDRAE server
• License

Screenshots

How it was built

Used technologies

• JavaScript (ES6 -TypeScript).
• Node.js + Express.js
• Chai + Mocha - testing.
• Heroku - production environment server.

Create your own DDRAE Telegram Bot

Create your own Telegram Bot

Create a new bot through the BotFather Bot (@BotFather).
More info about Telegram Bots here.

Set up your DDRAE server

1. Clone the repository.

   In order for your server to be able to start, the following need to be installed in your system:

   • Node.js
   • npm
   • gulp
   • TypeScript

2. Run npm install in order to install all the necessary node modules.

3. Set your own Telegram Bot API Token.

   This token is the one obtained when creating the Telegram Bot. You must change the variable TELEGRAM_API_BOT_TOKEN in src/utils/telegram/variables.ts.

4. Run the server.

   Run the server with the command the command sudo gulp nodemon. The sudo is necessary as we are running the server in the SSL port (443).
   The Node/Express server uses gulp in order to watch for TypeScript (.ts) file changes and automatically compiling them into JavaScript (.js) files which are the ones the server runs. The src/** TypeScript files are compiled inside the dist/ folder.
   The gulp tasks also restart the server whenever a .ts file is compiled into a .js one. This is done with gulp-nodemon.

   See the gulpfile.js in order check how gulp tasks work.

5. Enable SSL in your local server.

   In order for Telegram to communicate with your server you need to enable SSL. You can do this creating your self-signed SSL certificate using the following command:
   openssl req -newkey rsa:2048 -sha256 -nodes -keyout ssl_certs/YOURPRIVATE.key -x509 -days 365 -out ssl_certs/YOURPUBLIC.pem -subj "/C=<country>/ST=<state>/L=<city>/O=<organization>/CN=<server_public_address>".
   Note that you must change the following with your own info:

   • <country>
   • <state>
   • <city>
   • <organization>
   • <server_public_address>: the most important here is this. You must put your public IP address that points to your node server running in your computer. In my case as I didn't have a private domain I put here my public IP address (81.xxx.xx.xxx).

   Your certificates will be stored in the folder ssl_certs.

   You should test that your server is publicly accessible via https, in a browser like the following: https://81.xxx.xx.xxx. Note that it may be necessary to open/redirect ports in your router.

6. Connect your Telegram Bot with your server.

   The Telegram Bot API allows you to connect your server with yout bot with an easy API call. What we are doing is set up a webhook that, when someone sends a message to our bot in Telegram, will call our server API. We will make the call using curl through the command line:
   curl -F "certificate=@ssl_certs/YOURPUBLIC.pem" -F "url=https://<your_server_ip_address>/new-message" "https://api.telegram.org/bot<your_bot_token>/setWebhook"

   In the above command you need to put your own parameters (<your_server_ip_address> and <your_bot_token>). Note that we are sending to the API our self-signed certificate in order for Telegram to trust it.
   If you want to retrieve the info about your webhook, you can perform the following call:
   curl https://api.telegram.org/bot<your_bot_token>/getWebhookInfo
   If you want to delete your webhook you can perform the following one:
   curl https://api.telegram.org/bot<your_bot_token>/deleteWebhook

   Each time someone sends a message to our bot, the Telegram API will call our https://<your_server_ip_address>/new-message API end-point.

License

MIT License

This was built for learning purposes only. Anyone can clone the repository, learn how it was built and extend it's features.