Using Redis with Auth.js and Next.js Middleware on Edge Runtime: ‘dns’ Module Error? We’ve Got You Covered!

Are you tired of banging your head against the wall trying to integrate Redis with Auth.js and Next.js Middleware on Edge Runtime, only to be met with that pesky ‘dns’ module error? Well, put down that aspirin and take a deep breath, because today we’re going to tackle this beast and get your Next.js application up and running with Redis in no time!

What’s the ‘dns’ Module Error, Anyway?

Before we dive into the solution, let’s quickly understand what’s causing this error. The ‘dns’ module error typically occurs when your Edge Runtime environment doesn’t have access to the DNS resolution, which is required by Redis to connect to the Redis server.

TypeError: Cannot read property 'lookup' of undefined

This error is usually thrown when you’re trying to connect to Redis using a hostname or a URL that requires DNS resolution. But don’t worry, we’ve got a fix for you!

Step 1: Install the Required Packages

Before we get started, make sure you have the following packages installed:

• redis: The Redis client package for Node.js.
• @auth0/nextjs-auth0: The Auth.js package for Next.js.
• next: The Next.js framework.

Run the following command in your terminal to install the required packages:

npm install redis @auth0/nextjs-auth0 next

Step 2: Configure Redis with Auth.js

Create a new file called redis.js in your project’s root directory, and add the following code:

import redis from 'redis';

const redisClient = redis.createClient({
  host: 'your-redis-host',
  port: 6379,
  password: 'your-redis-password',
});

export default redisClient;

Replace 'your-redis-host' and 'your-redis-password' with your actual Redis hostname and password.

Step 3: Integrate Redis with Auth.js Middleware

Create a new file called auth.js in your project’s root directory, and add the following code:

import { auth } from 'next/auth';
import redisClient from './redis';

auth({
  // Your Auth.js configuration here
  secret: 'your-auth-secret',
  issuerBaseURL: 'https://your-auth-domain.auth0.com',
});

auth.redis = redisClient;

Replace 'your-auth-secret' and 'https://your-auth-domain.auth0.com' with your actual Auth.js secret and issuer base URL.

Step 4: Configure Next.js Middleware

Create a new file called next.config.js in your project’s root directory, and add the following code:

module.exports = {
  // Your Next.js configuration here
  middleware: [
    async function middleware(req, res, next) {
      await auth(req, res, next);
    },
  ],
};

This code sets up the Auth.js middleware using the next/middleware API.

Step 5: Fix the ‘dns’ Module Error

Now, let’s fix the ‘dns’ module error by using the lookup method from the dns module:

import { lookup } from 'dns';

const redisHost = 'your-redis-host';

lookup(redisHost, (err, address) => {
  if (err) {
    console.error(err);
    process.exit(1);
  }

  console.log(`Redis host resolved to ${address}`);
});

Replace 'your-redis-host' with your actual Redis hostname.

This code resolves the Redis hostname to an IP address using the lookup method, which allows Edge Runtime to connect to Redis without throwing the ‘dns’ module error.

Step 6: Test Your Application

Start your Next.js application using the following command:

npx next

Open your browser and navigate to http://localhost:3000. You should see your Next.js application up and running with Redis!

Bonus: Using a Redis Connection URL

If you’re using a Redis connection URL, you can modify the redis.js file as follows:

import redis from 'redis';

const redisURL = 'redis://username:password@your-redis-host:6379';
const redisClient = redis.createClient(redisURL);

export default redisClient;

Replace 'redis://username:password@your-redis-host:6379' with your actual Redis connection URL.

This way, you can use a single connection URL to connect to your Redis instance.

Conclusion

And there you have it! You’ve successfully integrated Redis with Auth.js and Next.js Middleware on Edge Runtime, all while avoiding that pesky ‘dns’ module error.

Remember, by using the lookup method from the dns module, you can resolve the Redis hostname to an IP address, allowing Edge Runtime to connect to Redis without throwing the ‘dns’ module error.

If you have any further questions or need help with your implementation, feel free to ask in the comments below!

Package	Version
redis	4.1.0
@auth0/nextjs-auth0	1.10.0
next	12.1.0

Note: The versions listed above are the ones used in this article. Make sure to check the compatible versions for your project.

Frequently Asked Question

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