server-routes.js

// Server side route to read data-form comming from mailgun
// /imports/startup/server/routes.js
import { Meteor } from 'meteor/meteor';
import { WebApp } from 'meteor/webapp';
import formidable from 'formidable';
import ical from 'ical';
import fs from 'fs';

const newSurveyFromMail = Meteor.bindEnvironment((senderMail, event) => {
  Meteor.call('newSurveyFromMail', senderMail, event);
});

WebApp.connectHandlers.use('/incomingmail', (request, response, next) => {
  // create temp dir if !exist
  const path = '/tmp';
  if (!fs.existsSync(path)) {
    fs.mkdirSync(path);
  }

  if (request && request.headers && request.headers['user-agent'] && request.headers['user-agent'].includes('mailgun')) {
    const form = new formidable.IncomingForm({ uploadDir: path });
    form.parse(request, (err, fields, files) => {
      if (err) {
        console.log('err:', err);
      }
      // we are only looking for mail with ics attached
      if (files && files['attachment-1'] && files['attachment-1'].name.includes('.ics')) {
        let event;
        const ics = ical.parseFile(files['attachment-1'].path);
        // remove id container of ics, just need root object
        for (const key in ics) {
          if (ics.hasOwnProperty(key)) {
            event = ics[key];
          }
        }

        let senderMail = fields.From;
        // Correct if mail format is like: Full Name <full.name@domain.com>
        if (senderMail.includes('<')) {
          const mailParts = senderMail.split('<');
          senderMail = mailParts[1].slice(0, -1);
        }
        // Call Meteor method
        newSurveyFromMail(senderMail, event);
      }
      response.statusCode = 200;
      response.end();
    });
  }
});