We Keep Coding

NodeJS Server Adress 80 already in use ERROR --> Running on debian 10 cloud server with apache2

I have an issue I can't resolve for a while now. If anyone has a clue, or could help me via TeamViewer, i'll pay reward of 100$. I need this working Monday.
So. I have a webserver set up on 46.231.206.172
There I initially installed an apache2 webserver to host my website under the domain magnolian.ch
Then I switched to a nodejs server though. So I uninstalled apache2 and instead, install a service for the nodejs server.js file.
This worked great on Port 80.
But now all of a sudden (Dont know why, even back 2 weeks of backups still error...).
When I try to load the site, it times out.
When I manually want to start the server via the command "node server.js" it gives the error:
Adress already in use on port 80.
So i have no clue what I need to do here. I cant find any process with Port 80.
lsof -i :80 returns nothing....
Theres no service running that I can seem to find out...
Any ideas?
Much love
Roger, let me know!
Discord for support: Hunter S. Thompson#0275
Code:
Server.js
const http = require('http');
const app = require('./app');
const server = http.createServer(app);
server.listen(80);
App.js
const express = require('express');
const bodyparser = require('body-parser');
const offerRoutes = require('./api/routes/offer');
const contactRoutes = require('./api/routes/contacts');
const userRoutes = require('./api/routes/users');
const aboutRoutes = require('./api/routes/abouts');
const servicesRoutes = require('./api/routes/services');
const newsRoutes = require('./api/routes/news');
const homeRoutes = require('./api/routes/home');
const technoRoutes = require('./api/routes/techno');
const errorRoutes = require('./api/routes/error');
const app = express();
app.use(bodyparser.urlencoded({extended: false}));
app.use(bodyparser.json());
app.set('view engine', 'ejs');
app.set('views', './api/views');
app.use(express.static(__dirname + '/public'));
app.use('/offer', offerRoutes);
app.use('/about', aboutRoutes);
app.use('/services', servicesRoutes);
app.use('/news', newsRoutes);
app.use('/techno', technoRoutes);
app.use('/contact', contactRoutes);
app.use('/user', userRoutes);
app.use('/', homeRoutes);
app.use('/*', errorRoutes);
app.listen(80, '127.0.0.1');
module.exports = app;

localhost:3000 JavaScript Problem in de app.get

I'm learning Js.
I have a problem in the code:
const express = require('express');
const app = express();
const PORT = 3000;
app.listen(PORT, function(){
console.log("The Express is running");
});
app.get('/', (req,res)=>{
res.send('Ok');
});
running node app.js i have the answer "Ok".But, running in the browser(localhost:3000) i get : "The connection was refused".
necessary info: I'm use a container docker, which I use the ubuntu. Can this cause a problem?

TypeError: Cannot create property 'next' on number '8080'

I am a newbie to node.js and was trying to create a sample web server with the code below but I got this error instead. could someone please point out/ explain what went wrong?
req.next = next;
^
TypeError: Cannot create property 'next' on number '8080'
// Setup empty JS object to act as endpoint for all routes
projectData = {};
// Require Express to run server and routes
const express = require('express');
// Start up an instance of app
const app = express();
/* Middleware*/
//Here we are configuring express to use body-parser as middle-ware.
const bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
// Cors for cross origin allowance
const cors = require('cors');
app.use(cors());
// Initialize the main project folder
app.use(express.static('Weather-Journal-App'));
// Setup Server
const port = 8080;
const server = app(port, listening)
function listening(){
console.log(`App server is up and running on localhost: port ${port}`);
};

I believe you want to use:
app.listen(port, listening)
instead of app(port, listenting)

How can i display the ip address exposing an express.js development server to other machines in the network?

When I start up a basic express.js server I usually console.log a message that says it is running and listening on port .
const express = require('express');
const app = express();
const port = 3000;
app.get('/', (req, res) => res.send('App reached.'));
app.listen(port, () => console.log(`Example app listening on port ${port}!`));
However, I would like to add to this message the available IP address exposing the app to other machines on the network. Somewhat like create-react-app basic template does. How can i reach that info with my javascript code?

Has indeed already been answered:
Get local IP address in node.js
I preferred this solution:
npm install ip
const express = require('express');
const ip = require('ip');
const ipAddress = ip.address();
const app = express();
const port = 3000;
app.get('/', (req, res) => res.send('App reached.'));
app.listen(port, () => {
console.log(`Example app listening on port ${port}!`);
console.log(`Network access via: ${ipAddress}:${port}!`);
});

Getting a " Cannot GET /" when attempting to retrieve a json object from a node server

I am writing a RESTful API. IT runs on node.js using the express.js framework, mongodb using mongoose as the object modelling tool & body-parser to pass the http. Everytime I start the server & navigate to the specified IP address, I get a "CANNOT GET/" error. How can I can around this? Some advice would be much appreciated .
I have tired using a different port number but the problem still persists.
Here is a copy of my server.js code:
var express = require('express'),
app = express(),
IP = process.env.IP,
port = process.env.PORT || 8080 ,
mongoose = require('mongoose'),
tasks = require('./api/models/todosModel'),
bodyParser = require('body-parser');
//handiling of promise
mongoose.Promise = global.Promise;
mongoose.connect('mongodb://localhost/Todosdb',{ useNewUrlParser: true });
app.use(bodyParser.urlencoded({extended:true})); // telling the sever instance to use body parser
app.use(bodyParser.json());
var Routes = require('./api/routes/todoRoutes');
//passing the server instance to the routes
Routes(app);
app.listen(port,IP);
console.log("The TODO API server is running on IP: " + IP + " and port: " + port);
The todoRoute code :
'use strict';
module.exports = function(app){
var todofunctions = require('../controllers/todoController');
// todo routes
app.route('/tasks') //task [GET (all the tasks),POST]
.get(todofunctions.listTasks)
.post(todofunctions.createTask);
app.route('/tasks/:taskId') //a task [GET(single task),PUT,DELETE]
.put(todofunctions.updatetask)
.get(todofunctions.readTask)
.delete(todofunctions.deleteTask);
};

It's probably because you have not defined any handler for /.
Try going to the /tasks instead in your browser, then you will get some response.