Installation

npm install get-user-ip --save

Getting Started

const GetUserIP = require('get-user-ip')
const http = require('http')

const server = http.createServer((req,res)=>{
  res.end(GetUserIP(req))
})

server.listen(6870)

// on localhost you'll see 127.0.0.1 if you're using IPv4
// or ::1, ::ffff:127.0.0.1 if you're using IPv6

If there are some special cases, such as the use of CloudFlare, you can append a second parameter, which is an array so it can contain more than one params

const server = http.createServer((req,res)=>{
  // This gives priority to getting headers.cf-connecting-ip, and if it doesn't exist, continue with the default parameters
  res.end(GetUserIP(req,['headers.cf-connecting-ip']))
})

How It Works

It looks for a specific header in the request and returns the 0.0.0.0 default if it does not exist

The user IP is determined by the following order

const defaultHeaders = [
  'headers.x-client-ip',
  'headers.x-real-ip',
  'headers.x-forwarded-for', // This header will return multiple IP addresses, Format: (Client IP, Proxy 1 IP, Proxy 2 IP...) So return the first
  'connection.remoteAddress',
  'socket.remoteAddress',
  'connection.socket.remoteAddress'
]