How to host nodejS+postgres application on digital-ocean? - node.js

Question

I have followed traversy media tutorial to deploy nodejs app on digital-ocean. I am using postgres database of digital ocean. However on running node app.js command I am getting error
I have tried to follow many answers on stackoverflow but they have not solved the problem
app.js
const express = require('express')
const bodyParser = require('body-parser')
const cors = require('cors')
const morgan = require('morgan')
const db = require('./queries') // contains all query functions
const port = 3000
const app = express()
app.use(morgan('combined'))
app.use(bodyParser.json())
app.use(
bodyParser.urlencoded({
extended: true,
})
)
app.use(cors())
app.get('/runs', db.getPlayers)
app.post('/year', db.getByYear)
//Handle production
app.use(express.static(__dirname+'/public/'))
//Handle SPA
app.get(/.*/, (request, response) => response.sendFile(__dirname+'/public/index.html') );
app.listen(port, () => {
console.log(`App running on port ${port}.`)
})
Error which I am getting is:-
events.js:183
throw er; // Unhandled 'error' event
^
Error: listen EADDRINUSE :::3000
at Object._errnoException (util.js:1022:11)
at _exceptionWithHostPort (util.js:1044:20)
at Server.setupListenHandle [as _listen2] (net.js:1367:14)
at listenInCluster (net.js:1408:12)
at Server.listen (net.js:1492:7)
at Function.listen (/home/vineet/IPL-Stats-Analysis-Dashboard/node_modules/express/lib/application.js:618:24)
at Object.<anonymous> (/home/vineet/IPL-Stats-Analysis-Dashboard/app.js:63:5)
at Module._compile (module.js:652:30)
at Object.Module._extensions..js (module.js:663:10)
at Module.load (module.js:565:32)

Answer 1

I am not familiar with said tutorial - but the error denotes that another process (probably the same express app) is already listening on port 3000.
On Linux you can list all running process with the command ps aux. Look for another node process. If there is none - you can find which processes are listening on which ports by running lsof -Pnl +M -i4 for ipv4 addresses and lsof -Pnl +M -i6 for ipv6.
Or simply do curl http://localhost:3000 in the Digitalocean droplet.

Answer 2

If were your OS is Linux, just type on your terminal which is killall -9 node