just4give/telegram-block

Balena block which connects your app to telegram bot

A block to integrate your balena application with telegram bot

Pre-requisite

Of course you need to create a telegram bot first before you can integrate with your application 😀 If you don't know how, follow this link for instructions.

Usage

docker-compose file

To use this image, create a container in your docker-compose.yml file as shown below:

version: "2.1"

volumes:
  shared-media:

services:
  telegram-block:
    image: mithundotdas/telegram-block:armv7hf
    restart: always
    network_mode: host
    volumes: 
            - 'shared-media:/var/media'
    environment:
            - TG_TOKEN=<your_telegram_token>
            - TG_CHAT_ID=<your_telegram_chat_id>

You can set your docker-compose.yml to build a Dockerfile file and use the dashboard block as the base image. docker-compose.yml:

version: "2"

volumes:
  shared-media:

services:
  telegram-block:
    build: ./
    restart: always
    network_mode: host
    volumes: 
            - 'shared-media:/var/media'
    environment:
            - TG_TOKEN=<your_telegram_token>
            - TG_CHAT_ID=<your_telegram_chat_id>

Dockerfile

FROM mithundotdas/telegram-block:%%BALENA_ARCH%%

mithundotdas/telegram-block is built for the following archs:

• aarch64
• armv7hf
• amd64
• rpi

Communication

Telegram block starts a MQTT broker on port 1883 (configurable). Your application communicates through the MQTT topics. Sample code which sends "pong" message to telegram app when any message is sent to the bot. To send any message (text, photo or audio), you need to send data to /tg/tx topic. To receive message from telegram, you need to listen to topic /tg/rx

const mqtt = require('mqtt');
const port = 1883;

const username = process.env.MQTT_USER;
const password = process.env.MQTT_PASSWORD;

const client = mqtt.connect(`mqtt://localhost:${port}`,{username: username, password: password});

  client.on('connect', function () {
    console.log(`connected to telegram block`);
    client.subscribe('/tg/rx');
    
  })

  client.on('message', function (topic, message) {
    
    client.publish('/tg/tx',  JSON.stringify({type:"text",text: "pong"}));
  })

  client.on('error', function (error) {
    console.log(error);
    
  })

Supported types are

• text
• photo
• audio

TX message format

{
  "type":"text",
  "text":"hello"
}

{
  "type":"photo",
  "photo":"/var/media/image.png"  //from local volume
}

{
  "type":"photo",
  "photo":"https://github.com/just4give/telegram-block/blob/6571079b983fe918867b113ec5c5c74cb99dc5b9/logo.png" //from absolute url
}

{
  "type":"audio",
  "photo":"/var/media/audio.wav"  //from local volume
}

Customization

mithundotdas/telegram-block can be configured via the following variables:

Environment Variable	Default	Description
TG_BROKER_USERNAME	balena	MQTT broker username
TG_BROKER_PASSWORD	balena	MQTT broker password
TG_BROKER_PORT	1883	MQTT broker port
TG_TOEKN		Telegram token. You must supply in docker-compose or variable
TG_CHAT_ID		Telegram chat id. You must supply in docker-compose or variable
TG_SEND_TOPIC	/tg/tx	MQTT Topic where you send data for it to be sent to the telegram
TG_RECEIVE_TOPIC	/tg/rx	Subscribe to this MQTT topic to receive messages sent from telegram

You can refer to the docs on how to set environment or service variables

Alternatively, you can set them in the docker-compose.yml or Dockerfile.template files.