Issue Deploying Next.js app to cPanel + LiteSpeed - Error: http.Server.listen() More Than Once

Question

I'm currently working on deploying my Next.js app (version 13.4.19) to a shared hosting provider that uses cPanel and LiteSpeed. Unfortunately, I'm encountering an error during deployment, and I could use some assistance in resolving it.

The error message I'm seeing is:

Error: http.Server.listen() was called more than once which is not allowed.
at Server.customListen [as listen] (/usr/local/lsws/fcgi-bin/lsnode.js:68:15)
at ipcPort (/home/[..webbroot..]/node_modules/next/dist/server/lib/server-ipc.js:73:17)
at new Promise (<anonymous>)
at createIpcServer (/home/[..webbroot..]/node_modules/next/dist/server/lib/server-ipc.js:72:27)
at initialize (/home/[..webbroot..]/node_modules/next/dist/server/lib/router-server.js:79:82)
at async Server.<anonymous> (/home/[..webbroot..]/node_modules/next/dist/server/lib/start-server.js:192:36)

As I'm on cPanel hosting, I can't use next start to run the app. Instead, I need to utilize the standalone build that results in a server.js file, which can be set as the entrypoint script for cPanel.

After researching, I discovered that LiteSpeed has a bootstrap node script called /usr/local/lsws/fcgi-bin/lsnode.js. I suspect that this lsnode.js script and Next.js might not be fully compatible.

My Questions:

1. Has anyone encountered a similar issue when deploying a Next.js app to cPanel + LiteSpeed?
2. Do you have any insights or ideas on how to address this problem and make Next.js and LiteSpeed work together seamlessly in this setup?

Thank you in advance for your help!

---

I found this document from Phusion Passenger. https://www.phusionpassenger.com/library/indepth/nodejs/reverse_port_binding.html But I have not managed to get this solution to work in the Next.js library.

I embed the source code of the lsnode.js script below:

/*
 * Copyright 2002-2018 Lite Speed Technologies Inc, All Rights Reserved.
 * LITE SPEED PROPRIETARY/CONFIDENTIAL.
 */

var EventEmitter = require('events').EventEmitter;
var os = require('os');
var fs = require('fs');
var http = require('http');
var util = require('util');
var net = require('net');

var socketObject = { fd: 0 };
module.isApplicationLoader = true;
global.LsNode = new EventEmitter();
startApplication();

function startApplication() {
    var appRoot = process.env.LSNODE_ROOT || process.cwd();
    var startupFile = process.env.LSNODE_STARTUP_FILE || 'app.js';
    LsNode.listenDone = false;

    if (process.env.LSNODE_ROOT != undefined) {
        try {
            process.chdir(process.env.LSNODE_ROOT);
        } catch (err) {
            console.error("Error setting directory to: " + 
                          process.env.LSNODE_ROOT + ": " + err);
        }
    }
    if (!startupFile.startsWith('/')) {
        startupFile = appRoot + '/' + startupFile;
    }

    process.title = 'lsnode:' + appRoot;

    var consoleLog = process.env.LSNODE_CONSOLE_LOG || '/dev/null';
    fs.closeSync(1);
    try {
        fs.openSync(consoleLog, "w+");
    } catch(e) {
        fs.openSync('/dev/null', "w+");
    }
    
    http.Server.prototype.realListen = http.Server.prototype.listen;
    http.Server.prototype.listen = customListen;
    http.Server.prototype.address = lsnode_address;
    var app = require(startupFile);
    if (!LsNode.listenDone) {
        if (typeof app.listen === "function")
            app.listen(3000);
    }
}


function lsnode_address() {
    return process.env.LSNODE_SOCKET;
}


function customListen(port) {
    function onListenError(error) {
        server.emit('error', error);
    }
    // The replacement for the listen call!
    var server = this;
    if (LsNode.listenDone) {
        throw new Error("http.Server.listen() was called more than once " +
                        "which is not allowed.");
    }
    LsNode.listenDone = true;

    var listeners = server.listeners('request');
    var i;
    server.removeAllListeners('request');
    server.on('request', function(req) {
        req.connection.__defineGetter__('remoteAddress', function() {
            return '127.0.0.1';
        });
        req.connection.__defineGetter__('remotePort', function() {
            return port;
        });
        req.connection.__defineGetter__('addressType', function() {
            return 4;
        });
    });
    for (i = 0; i < listeners.length; i++) {
        server.on('request', listeners[i]);
    }

    var callback;
    if (arguments.length > 1 && typeof(arguments[arguments.length - 1]) == 'function') {
        callback = arguments[arguments.length - 1];
    }
    server.once('error', onListenError);
    server.realListen(socketObject, function() {
        server.removeListener('error', onListenError);
        if (callback) {
            server.once('listening', callback);
        }
        server.emit('listening');
    });
    return server;
}

Answer 1

I also ran into this issue with running an API that was using Fastify. By default, Fastify listens to localhost while it appears that LightSpeed aims to use 127.0.0.1

I changed my code to resemble this and it works now as expected:

const Fastify = require('fastify');

const app = Fastify();

app.get('/', (req, res) => {
  res.send({ hello: 'world' });
});

app.listen({ 
    port: process.env.PORT || 4201,
    host: '127.0.0.1'
});

So in your instance I'm not sure what Next.js uses under the hood for it's SSR, but try changing the host. Another note is that Express 4 works out of the box as well, so if there is an option to change the http engine/library that might be an option as well.