I have a problem with IP when my express app is behind Nginx.

I’ve gone through this guide and it works.

Express behind proxies

Express

Below I will demo how I manage to get the real IP.

Server setup

I go for AWS EC2 Ubuntu 20.04 quick setup and ssh into it.

Nginx Minimal Setup

Install Nginx.

Edit the config file in /etc/nginx/site-enabled

server {
    listen 80;
    location /this-is-me/ {
        proxy_pass http://localhost:9999/;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

Express Minimal Setup

Set up your minimal express app npm init --yes

I add type: module here in package.json since I want to use import syntax.

import express from 'express'
const app = express()
app.use((req, res) => {
    return res.json({
        timestamp: Date.now(),
        your_ip: req.ip
    })
})
app.set('trust proxy', ['loopback', 'linklocal','uniquelocal'])
app.listen(9999, () => {
    console.log('listening on 9999')
})

Run it with node app.js

Check the result locally with curl http://localhost:9999

Testing

curl http://<your_ip_here>/this-is-me

You can check result against Google search of “my ip”

Hope this help!