Sending Webhook Messages from Heroku to Discord

In this article, we delve into the seamless integration of Heroku, a popular cloud platform, with Discord, a widely used communication platform. The focus is on sending webhook messages from Heroku to Discord, enhancing real-time updates and notifications for various applications. The article guides readers through the process, offering a step-by-step approach to set up and configure webhooks, ensuring efficient and automated communication between Heroku-hosted applications and Discord channels. With this integration, users can stay informed, monitor events, and streamline communication effortlessly.

In order to communicate between Heroku and Discord we need to create a small application to parse our webhook messages to the format from Discord. The app contains the following aspects:

Features

  1. Express.js Server Setup:
    • Utilizes the Express.js framework to create a web server.
    • Listens on the specified port (process.env.PORT or defaulting to 3000).
  2. Heroku Webhook Handling:
    • Provides a route (/heroku-webhook) to handle incoming Heroku webhook events.
    • Extracts relevant data from the Heroku webhook payload, including event data and metadata.
    • Formats a message based on the extracted data to provide a concise summary of the Heroku event.
  3. Discord Webhook Integration:
    • Utilizes the Axios library to send a formatted payload to a Discord webhook.
    • The Discord payload includes an embed with information about the Heroku event.
  4. Environment Variable Usage:
    • Uses process.env to read the PORT and DISCORD_WEBHOOK environment variables.s.
    • Provides default values for PORT (3000) and logs the DISCORD_WEBHOOK value.

You can find the code I used on my GitHub Repository.

Setup

We will need some dependencies to create our application. Let’s install them using the following commands:

npm init
npm install [email protected]
npm install [email protected]
npm install [email protected]

You should be able to obtain a package.json file similar to mine:

{
  "name": "heroku-discord",
  "version": "1.0.0",
  "description": "Parser for heroku webhook messages to discord webhook messages",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/WebCDC/heroku-discord.git"
  },
  "author": "Rui Coelho",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/WebCDC/heroku-discord/issues"
  },
  "homepage": "https://github.com/WebCDC/heroku-discord#readme",
  "dependencies": {
    "axios": "^1.6.5",
    "body-parser": "^1.20.2",
    "express": "^4.18.2"
  }
}

Let’s create an index.js file:

const express = require('express');
const bodyParser = require('body-parser');
const axios = require('axios');

const app = express();
const port = process.env.PORT || 3000;
const webhook = process.env.DISCORD_WEBHOOK;

console.log(webhook)

app.use(bodyParser.json());

app.post('/heroku-webhook', (req, res) => {
  // Extract relevant data from Heroku webhook payload
  const herokuEventData = req.body.data;
  const herokuEventMetada = req.body.webhook_metadata;


  const message = `Event ID => ${herokuEventMetada.event.id}\nEvent Type => ${herokuEventMetada.event.include}\nTriggered by => ${herokuEventData.user.email}\nStatus => ${herokuEventData.status}`


  // Transform data to match Discord webhook payload structure
  const discordPayload = {
    embeds: [
      {
        title: 'Heroku Notification',
        description: message,
        fields: [
          { name: 'App Name', value: herokuEventData.app.name, inline: true },
          // Add more fields as needed
        ],
      },
    ],
  };

  // Send payload to Discord webhook
  axios.post(`${webhook}`, discordPayload)
    .then(() => res.sendStatus(200))
    .catch(error => {
      console.error('Error sending Discord webhook:', error);
      res.sendStatus(500);
    });
});

app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});

Let’s break this code down.

Dependencies

  • express: A web application framework for Node.js.
  • body-parser: Middleware to parse incoming request bodies in a middleware before your handlers.
  • axios: A promise-based HTTP client for the browser and Node.js.
const express = require('express');
const bodyParser = require('body-parser');
const axios = require('axios');

Application Setup

  • Creates an instance of the Express application.
  • Defines the port for the server to run on (using the environment variable PORT or defaulting to 3000).
  • Retrieves the Discord webhook URL from the environment variable DISCORD_WEBHOOK.
const app = express();
const port = process.env.PORT || 3000;
const webhook = process.env.DISCORD_WEBHOOK;

Middleware Setup

  • Uses body-parser middleware to parse incoming JSON requests.
app.use(bodyParser.json());

Webhook Handling

  • Defines a route (/heroku-webhook) to handle incoming POST requests from Heroku.
  • Extracts relevant data from the Heroku webhook payload.
  • Formats a message using the extracted data.
  • Creates a Discord payload with an embed object containing the formatted message and additional information.
  • Sends the payload to the specified Discord webhook.

app.post('/heroku-webhook', (req, res) => {
  // ... (Handling Heroku webhook data)

  // Transform data to match Discord webhook payload structure
  const discordPayload = {
    embeds: [
      {
        title: 'Heroku Notification',
        description: message,
        fields: [
          { name: 'App Name', value: herokuEventData.app.name, inline: true },
          // Add more fields as needed
        ],
      },
    ],
  };

  // Send payload to Discord webhook
  axios.post(`${webhook}`, discordPayload)
    .then(() => res.sendStatus(200))
    .catch(error => {
      console.error('Error sending Discord webhook:', error);
      res.sendStatus(500);
    });
});
Server Initialization
Starts the server and listens on the specified port.
app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});

Server Initialization

  • Starts the server and listens on the specified port.
app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});