Remote IP address with node-js behind amazon ELB

Question

I have a node application on an instance-store amazon machine behind the elastic load balancer (elb). However, the remote IP adress seems to always be the same. I used this code to get the client's IP address in node (via connect/express):

req.socket.remoteAddress

I didn't get anything else from the node documentation. Any hint?

Answer 1

The answer worked for me, thanks. But you may just try:

var ip_address = null;
if(req.headers['x-forwarded-for']){
    ip_address = req.headers['x-forwarded-for'];
}
else {
    ip_address = req.connection.remoteAddress;
}
sys.puts( ip_address );

Answer 2

Here's a solution in case you are using express:
According to the documentation, you can enable trust proxy for your express instance and then req.ip will be populated with the correct ip address.

By enabling the "trust proxy" setting via app.enable('trust proxy'), Express will have knowledge that it's sitting behind a proxy and that the X-Forwarded-* header fields may be trusted, which otherwise may be easily spoofed.

Enabling this setting has several subtle effects. The first of which is that X-Forwarded-Proto may be set by the reverse proxy to tell the app that it is https or simply http. This value is reflected by req.protocol.

The second change this makes is the req.ip and req.ips values will be populated with X-Forwarded-For's list of addresses.

Here's an example:

var app = express();
app.enable('trust proxy');
// ...

app.use(function(req, res, next) {
  console.log('client ip address:', req.ip);
  return next();
});