Web frameworks in Node.js provide a request object containing information from the requesting instance. The request object typically includes the IP address of the requesting client. If you want to geo-locate the requesting user, the IP address is helpful.
This tutorial shows you how to retrieve the client IP address from a request instance in Node.js.
Node.js Series Overview
- Increase the Memory Limit for Your Process
- Why You Should Add “node” in Your Travis Config
- Create a PDF from HTML with Puppeteer and Handlebars
- Create Your Own Custom Error
- Extend Multiple Classes (Multi Inheritance)
- Get a File’s Created Date
- Get a File’s Last Modified/Updated Date
- Write a JSON Object to a File
- How to Create an Empty File
- Generate a Random Number in Range With JavaScript/Node.js
- How to Merge Objects
- Retrieve a Request’s IP Address in Node.js
- Detect the Node.js Version in a Running Process or App
- String Replace All Appearances
- Remove All Whitespace From a String in JavaScript
- Generate a Random String in Node.js or JavaScript
- Remove Extra Spaces From a String in JavaScript or Node.js
- Remove Numbers From a String in JavaScript or Node.js (Coming soon)
- Get the Part Before a Character in a String in JavaScript or Node.js (Coming soon)
- Get the Part After a Character in a String in JavaScript or Node.js (Coming soon)
- How to Check if a Value is a String in JavaScript or Node.js (Coming soon)
- How to Run an Asynchronous Function in Array.map()
- How to Reset and Empty an Array
- for…of vs. for…in Loops
- Clone/Copy an Array in JavaScript and Node.js
- Get an Array With Unique Values (Delete Duplicates)
- Sort an Array of Integers in JavaScript and Node.js
- Sort a Boolean Array in JavaScript, TypeScript, or Node.js (Coming soon)
- Callback and Promise Support in your Node.js Modules
- Run Async Functions/Promises in Sequence
- Run Async Functions/Promises in Parallel
- Run Async Functions in Batches
- How to Fix “Promise resolver undefined is not a function” in Node.js or JavaScript
- Detect if Value Is a Promise in Node.js and JavaScript
- How to Check if an Object is Empty in JavaScript or Node.js (Coming soon)
Get the Request IP Address
The request can carry the client’s IP address in different locations. For example, it may be stored in an HTTP request header like x-forwarded-for, in one of the request properties like request.connection, request.socket, request.info, or request.raw.
Serverless environments provide a request context. For example, in AWS Lambda functions using AWS API Gateway you may have the IP address stored in an identity property carrying the sourceIp.
The @supercharge/request-ip package streamlines the process retrieving the request’s IP address. It checks dozens of possible locations and returns the found IP address.
At first, install the package as a dependency of your project:
npm install @supercharge/request-ip
Then, go ahead and retrieve IP address from the request object like this:
const RequestIp = require('@supercharge/request-ip')
const ip = RequestIp.getClientIp(request)
// for example '213.211.254.97' as an IP v4 address
// or '2001:0db8:85a3:0000:0000:8a2e:0370:7334' as an IP v6 address
// or 'undefined' if no IP address is available on the given request
That’s it. Pass the request object to the RequestIp.getClientIp(request) function and it returns the IP address (or undefined if nothing was found).
Detect the IP Address in Frameworks Like Express/hapi/Fastify/Koa/Co.
Depending on your web framework of choice and use case, you may need to retrieve the IP address in a middleware or route handler.
Here are two basic examples showing how to retrieve the IP address in an Express middleware and hapi route handler:
simple Express middleware example
const RequestIp = require('@supercharge/request-ip')
const expressMiddleware = function (req, res, next) {
req.ip = RequestIp.getClientIp(req)
next()
}
simple hapi route handler example:
const Hapi = require('@hapi/hapi')
const RequestIp = require('@supercharge/request-ip')
const server = new Hapi.Server({
host: 'localhost'
})
server.route({
method: 'GET',
path: '/login',
handler: (request, h) => {
const ip = RequestIp.getClientIp(request)
return h.response(ip)
}
})
The @supercharge/request-ip package comes handy when retrieving a client’s IP address from a request instance!