Rocket.Chat/app/file-upload/server/lib/proxy.js

import http from 'http';
import URL from 'url';

import { Meteor } from 'meteor/meteor';
import { WebApp } from 'meteor/webapp';
import { UploadFS } from 'meteor/jalik:ufs';
import { InstanceStatus } from 'meteor/konecty:multiple-instances-status';

import { Logger } from '../../../logger';
import { isDocker } from '../../../utils';

const logger = new Logger('UploadProxy');

WebApp.connectHandlers.stack.unshift({
	route: '',
	handle: Meteor.bindEnvironment(function (req, res, next) {
		// Quick check to see if request should be catch
		if (!req.url.includes(`/${UploadFS.config.storesPath}/`)) {
			return next();
		}

		logger.debug({ msg: 'Upload URL:', url: req.url });

		if (req.method !== 'POST') {
			return next();
		}

		// Remove store path
		const parsedUrl = URL.parse(req.url);
		const path = parsedUrl.pathname.substr(UploadFS.config.storesPath.length + 1);

		// Get store
		const regExp = new RegExp('^/([^/?]+)/([^/?]+)$');
		const match = regExp.exec(path);

		// Request is not valid
		if (match === null) {
			res.writeHead(400);
			res.end();
			return;
		}

		// Get store
		const store = UploadFS.getStore(match[1]);
		if (!store) {
			res.writeHead(404);
			res.end();
			return;
		}

		// Get file
		const fileId = match[2];
		const file = store.getCollection().findOne({ _id: fileId });
		if (file === undefined) {
			res.writeHead(404);
			res.end();
			return;
		}

		if (file.instanceId === InstanceStatus.id()) {
			logger.debug('Correct instance');
			return next();
		}

		// Proxy to other instance
		const instance = InstanceStatus.getCollection().findOne({ _id: file.instanceId });

		if (instance == null) {
			res.writeHead(404);
			res.end();
			return;
		}

		if (instance.extraInformation.host === process.env.INSTANCE_IP && isDocker() === false) {
			instance.extraInformation.host = 'localhost';
		}

		logger.debug(`Wrong instance, proxing to ${instance.extraInformation.host}:${instance.extraInformation.port}`);

		const options = {
			hostname: instance.extraInformation.host,
			port: instance.extraInformation.port,
			path: req.originalUrl,
			method: 'POST',
		};

		logger.warn(
			'UFS proxy middleware is deprecated as this upload method is not being used by Web/Mobile Clients. See this: https://docs.rocket.chat/api/rest-api/methods/rooms/upload',
		);
		const proxy = http.request(options, function (proxy_res) {
			proxy_res.pipe(res, {
				end: true,
			});
		});

		req.pipe(proxy, {
			end: true,
		});
	}),
});