Google Cloud Functions で SendGridの Inbound Parse Webhook を受けて Discordに投げる

README.md

SendGrid - Discord

Relay SendGrid Inbound Parse Webhook to Discord

Environment Variables

Key	Description
WEBHOOK_DISCORD	Discord Webhook URL

index.js

const fetch = require('node-fetch');
const htmlToText = require('html-to-text');
const Busboy = require('busboy');
// const inspect = require('util').inspect;
const webhookUrl = process.env.WEBHOOK_DISCORD;

function create_message(fields){
  message = "From: "+ fields.from + "\n"
          + "To: "+ fields.to + "\n"
          + "Subject: "+ fields.subject + "\n"
          + "Body: "+ (fields.text || htmlToText.fromString(fields.html)) + "\n";
  return message
}

async function send_message(fields){
    const url = webhookUrl;
    const body = {
      content: create_message(fields)
    };
    const options = {
      method: 'POST',
      body:    JSON.stringify(body),
      headers: { 'Content-Type': 'application/json' },
    };
    return await fetch(url, options);
}

/**
 * HTTP Cloud Function that makes an HTTP request
 *
 * @param {Object} req Cloud Function request context.
 * @param {Object} res Cloud Function response context.
 */
exports.makeRequest = async (req, res) => {
  if (req.method != 'POST') return res.sendStatus(405); // method not allowed
//   console.log("Mail coming");
  var fields = {};
  var busboy = new Busboy({ headers: req.headers });
  busboy.on('field', function(fieldname, val, fieldnameTruncated, valTruncated, encoding, mimetype) {
    // console.log('Field [' + fieldname + ']: value: ' + inspect(val));
    fields[fieldname] = val;
  });
  busboy.on('file', function(fieldname, file, filename, encoding, mimetype) {
    // console.log('File [' + fieldname + ']: filename: ' + filename + ', encoding: ' + encoding + ', mimetype: ' + mimetype);
    file.on('data', function(data) {
    //   console.log('File [' + fieldname + '] got ' + data.length + ' bytes');
    });
    file.on('end', function() {
    //   console.log('File [' + fieldname + '] Finished');
    });
  });
  busboy.on('finish', async () => {
    // console.log('Done parsing form!');
    const externalRes = await send_message(fields);
    res.sendStatus(externalRes.ok ? 200 : 500);
  });
  busboy.end(req.rawBody);
};

package.json

{
  "name": "sendgrid-discode",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "npx @google-cloud/functions-framework --target=makeRequest"
  },
  "author": "m2wasabi@gmail.com",
  "license": "MIT",
  "dependencies": {
    "busboy": "^0.3.1",
    "html-to-text": "^5.1.1",
    "node-fetch": "^2.6.0"
  },
  "devDependencies": {
    "@google-cloud/functions-framework": "^1.6.0"
  }
}