Build a Custom Drone.io Telegram Notification Plugin with Node.js and Docker

Introduction

The author, a former front‑end engineer at Qiwuchuan, shares how to write a Drone.io plugin in Node.js that sends Telegram messages, a solution especially useful for users behind Chinese firewalls who need to proxy Telegram API requests.

Principle

Drone runs each plugin inside a Docker container and injects build information and plugin configuration as environment variables (e.g., PLUGIN_TOKEN , DRONE_COMMIT ). Any language can read these variables, enabling language‑agnostic plugin development.

Plugin configuration variables are prefixed with PLUGIN_ (e.g., PLUGIN_TOKEN ).

Build‑related information is prefixed with CI_ or DRONE_ (e.g., DRONE_COMMIT ).

Write the Plugin

The plugin reads required configuration from environment variables and uses node-telegram-bot-api to send a message. The core code is straightforward:

const render = require('drone-render');
const TelegramBot = require('node-telegram-bot-api');

const {
  PLUGIN_TOKEN,
  PLUGIN_TO,
  TELEGRAM_TOKEN,
  TELEGRAM_TO,
  PLUGIN_LANG,
  PLUGIN_MESSAGE,
  PLUGIN_BASE_API_URL
} = process.env;

const TOKEN = PLUGIN_TOKEN || TELEGRAM_TOKEN;
const TO = PLUGIN_TO || TELEGRAM_TO;

if (PLUGIN_LANG) {
  render.locale(PLUGIN_LANG);
}

const bot = new TelegramBot(TOKEN, {
  baseApiUrl: PLUGIN_BASE_API_URL
});

bot.sendMessage(TO, render(PLUGIN_MESSAGE));

The code is intentionally minimal.

Dockerfile

After writing the plugin, create a Dockerfile. To keep the image size small, install dependencies in an early layer and copy the script later:

FROM mhart/alpine-node:8.9.3

WORKDIR /telegram-node
COPY package.json /telegram-node/package.json
RUN npm install

COPY index.js /telegram-node/index.js
ENTRYPOINT [ "node", "/telegram-node/index.js" ]

Build and Publish

Build the image and push it to Docker Hub so others can use the plugin:

docker build lizheming/drone-telegram-node .
docker push lizheming/drone-telegram-node

Testing

Run the image locally with the required environment variables to verify it works:

docker run --rm \
  -e PLUGIN_TOKEN=xxxxxxx \
  -e PLUGIN_TO=xxxxxxx \
  -e PLUGIN_MESSAGE=test \
  -e PLUGIN_BASE_API_URL=xxxx \
  lizheming/drone-telegram-node

Secrets Management

To avoid exposing sensitive data in .drone.yml , store them as Drone secrets. The secret name becomes the environment variable name inside the plugin (e.g., TELEGRAM_TOKEN ).

pipeline:
  telegram:
    image: lizheming/drone-telegram-node
    secrets: [ telegram_token, telegram_to ]
    message: hello

Common Issue: Plugin Not Running

If the Dockerfile sets WORKDIR , Drone may override it during execution, causing the entrypoint script to be missing. Adjust the ENTRYPOINT to use an absolute path (as shown above) to resolve this.

Conclusion

The complete source code is available on GitHub ( https://github.com/lizheming/drone-telegram-node ) and the Docker image is published on Docker Hub. This plugin improves on the official one by allowing a custom Telegram API base URL, making it suitable for deployments behind proxies.