app.js

#!/usr/bin/env node

/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

const cfenv = require('cfenv');
const express = require('express');
const fs = require('fs');
const http = require('http');
const path = require('path');
const proxy = require('http-proxy-middleware');
const proxyConfig = require('./proxy.conf.js');

const app = express();
const appEnv = cfenv.getAppEnv();
const server = http.createServer(app);

const dist = path.join(__dirname, 'dist');
if (!fs.existsSync(dist)) {
    console.error('no dist directory - try running "npm run build" first');
    process.exit(1);
}
const static = express.static(dist);

app.use(static);
app.listen(4200);
app.use(express.static("public"));
proxyConfig.forEach((element) => {
    const context = element.context;
    delete element.context;
    const proxyMiddleware = proxy(context, element);
    app.use(function (req, res, next) {
        const bypass = typeof element.bypass === 'function';
        const bypassUrl = bypass && element.bypass(req, res, element) || false;
        if (bypassUrl) {
            req.url = bypassUrl;
            return static(req, res, next);
        } else {
            return proxyMiddleware(req, res, next);
        }
    });
	
});
server.listen(appEnv.port, function () {
    console.log('server starting on ' + appEnv.url);
});