I tried the following solution:
app.enable('trust proxy');
...
console.log(req.ip); // gives ::ffff:127.0.0.1
console.log(req.ips); // gives []
console.log(req.header('x-forwarded-for')); // gives undefined
console.log(req.connection.remoteAddress); // gives ::ffff:127.0.0.1
Is there any other way?
Is this a symptom of a bigger problem?
If you want to use the X-Forwarded-For header then you need to set it with nginx first:
proxy_set_header X-Forwarded-For $remote_addr;
See the docs: