How to determine a user's IP address in node

Question

How can I determine the IP address of a given request from within a controller? For example (in express):

app.post(\'/get/ip/address\', function (req, res) {         


        

Answer 1

I have tried all of them didn't work though,

console.log(clientIp);
console.log(req.ip);

console.log(req.headers['x-forwarded-for']);
console.log(req.connection.remoteAddress);
console.log(req.socket.remoteAddress);
console.log(req.connection.socket.remoteAddress.split(",")[0]);

When running an Express app behind a proxy for me Nginx, you have to set the application variable trust proxy to true. Express offers a few other trust proxy values which you can review in their documentation, but below steps worked for me.

1. app.set('trust proxy', true) in your Express app.

app.set('trust proxy', true);

2. Add proxy_set_header X-Forwarded-For $remote_addr in the Nginx configuration for your server block.

  location /  {
                proxy_pass    http://localhost:3001;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection 'upgrade';
                proxy_set_header Host $host;
                proxy_set_header X-Forwarded-For $remote_addr;  # this line
                proxy_cache_bypass $http_upgrade; 
        }

3. You can now read off the client’s IP address from the req.header('x-forwarded-for') or req.connection.remoteAddress; Full code for ipfilter

module.exports =  function(req, res, next) {
    let enable = true; // true/false
    let blacklist = ['x.x.x.x'];
    let whitelist = ['x.x.x.x'];
    let clientIp = req.header('x-forwarded-for') || req.connection.remoteAddress;
    if (!clientIp) {
        return res.json('Error');
    }
    if (enable
        && paths.some((path) => (path === req.originalUrl))) {

        let blacklist = blacklist || [];
        if (blacklist.some((ip) => clientIp.match(ip) !== null)) {
            return res.json({ status: 401, error: 'Your IP is black-listed !'});
        }
        let whitelist = whitelist || [];
        if (whitelist.length === 0 || whitelist.some((ip) => clientIp.match(ip) !== null)) {
            next();
            return;
        } else {
            return res.json({ status: 401, error: 'Your IP is not listed !'});
        }
    }
    next();
};