Today, we will explore how to use @nx/netlify serverless functions to determine a user's location. This can be an incredibly useful feature in various applications, such as customizing user experiences based on their region, displaying localized content, or tracking user demographics for marketing purposes. In this post, we'll walk you through a step-by-step guide on implementing this functionality using @nx/netlify serverless functions.

Before we get started though, here's a video introduction to the new @nx/netlify package:

Step 1: Set up your Nx workspace with Netlify

To get started, you need to have an Nx workspace. If you haven't already, create a new Nx workspace by running:

npx create-nx-workspace user-location --preset=@nx/netlify

This should create a default function inside src/functions/hello/hello.ts, which can be safely deleted if necessary.

Step 2: Create a serverless function

mkdir src/functions/user-location
touch src/functions/user-location/user-location.ts

Step 3: Determine the user's location

To determine the user's location, we will leverage the request.headers object, specifically the x-forwarded-for header containing the user's IP address. We can then use an IP geolocation API like ipapi (https://ipapi.co/) to fetch location data based on this IP address.

Note in Node.js 18, the experimental global fetch API is available by default. If you are using a node version lower than 18 you can install node-fetch to handle API requests:

Now, update the user-location.ts file with the following code:

import { Handler } from "@netlify/functions";
import fetch from "node-fetch"; // Can be removed if node >= 18

export const handler: Handler = async (event, _) => {
  const ip = event.headers["x-forwarded-for"];
  const url = `https://ipapi.co/${ip}/json/`;
  try {
    const response = await fetch(url);
    const data = await response.json();
    return {
      statusCode: 200,
      body: JSON.stringify({
        location: {
          city: data.city,
          region: data.region,
          country: data.country,
        },
      }),
    };
  } catch (error) {
    return { statusCode: 500, body: `Error fetching user location` };
  }
};

Step 4: Deploy your serverless function

When we created our workspace, the initial scaffolding generated a deploy-target inside our project.json.

A target is a specific task you can run for a project.
You can think of it as a script/command that does a specific job. The most common targets are "build", "serve", "test", "lint", "deploy", etc. For more information regarding project.json you can read about it at project-configuration

We can start off by creating our site on Netlify by running:

After you have answered all the prompts your site should be created. A .netlify folder should be created with references to your newly created site.

Now, to deploy your serverless function run:

Finally, navigate to your Netlify site's Functions tab, and you should see your user-location function deployed and ready to use!

For example, ours can be found at: https://644a9b17d0299b00b581b33f--find-user-location.netlify.app/.netlify/functions/user-location

{ "location": { "city": "Miami", "region": "Florida", "country": "US" } }

By following these steps, you've successfully used @nx/netlify serverless function to determine a user's location!

Wrapping up

Never used Nx before? Learn more about Nx here.
Official recipe from Nx
Github example

Learn more

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