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
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- Retrieve a Request’s IP Address in Node.js
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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!