Basic load balancing NodeJS (Nginx + PM2 + Express)

app.js

import express from 'express';
// ... So much space for unstable dependency imports ...

let app = express();

// ... Insert your own routing magic ...

export default app;

devqa.json

{
  "apps": [
    {
      "name": "Solve World Hunger",
      "script": "www.js",
      "instances": 3,
      "exec_mode": "fork",
      
      "env_devqa": {
        "PORT": 8000
      }
    }
  ],
  "deploy": {
    "devqa": {
      "user": "",
      "host": "",
      "ref": "origin/devqa",
      "repo": "",
      "path": "/var/www",
      "post-deploy": "npm isntall; pm2 startOrRestart devqa.json"
    }
  }
}

worldhunger.conf

# Nginx Sample App Conf

# Upstream
#
upstream worldhunger_upstream {
  least_conn;
  server 127.0.0.1:8001;
  server 127.0.0.1:8002;
  server 127.0.0.1:8003;
}

server {
  listen 80;
  server_name worldhungerfixednextproblem.com;
  
  location / {
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_set_header X-NginX-Proxy true;
  
    proxy_pass http://worldhunger_upstream;
  }
}

www-instance.js

import app from 'app';
import https from 'http';

let instance  = +process.env.NODE_APP_INSTANCE || 0;
let port      = (+process.env.PORT || 3000) + instance;

let server    = http.createSerevr( app );

app.set( 'port', port );
server.listen( port );

// ... Instance logging, you get the idea...