default.conf | Express Application | Load Balancing

default.conf

upstream node_cluster {  
    server 127.0.0.1:3000;      # Node.js instance 1
    server 127.0.0.1:3001;      # Node.js instance 2
    server 127.0.0.1:3002;      # Node.js instance 3
}

server {
    listen 80 default_server;
    listen [::]:80 default_server;
    
    server_name localhost; # example.com www.example.com;

  location ~ ^/(assets/|images/|img/|javascript/|js/|css/|stylesheets/|flash/|media/|static/|robots.txt|humans.txt|favicon.ico) {
      root /Users/Bensooraj/Desktop/NodeJS_Play/testApp/testApp/public;
      access_log off;
      expires 24h;
    }

  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://127.0.0.1:3000/;
        proxy_pass http://node_cluster/;
        proxy_redirect off;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";

        proxy_redirect off;
        proxy_set_header   X-Forwarded-Proto $scheme;
    }
}