How to forward request IP from NGINX to node.js application?

This solves it taking into consideration above NGINX config.

var ip = req.headers['x-real-ip'] || req.connection.remoteAddress;

Express.js official site has this guide. Instructions:

1. app.set('trust proxy', true) in js.
2. proxy_set_header X-Forwarded-For $remote_addr in nginx.conf
3. You can now read-off the client IP address from req.ip property