Step by Step Guide to Building an Auth0 API Integration in Go

Aug 8, 2024 • 6 minute read

Introduction

Hey there, fellow Go enthusiast! Ready to supercharge your app with Auth0's powerful authentication and authorization features? You're in the right place. In this guide, we'll walk through building an Auth0 API integration in Go. It's easier than you might think, and I promise you'll come out the other side with a robust, secure integration. Let's dive in!

Prerequisites

Before we start coding, make sure you've got:

A Go environment set up (I know you've probably got this sorted already)
An Auth0 account and application (If not, hop over to Auth0 and set one up – it's quick and painless)

Setting up the project

First things first, let's get our project structure in order:

mkdir auth0-go-integration
cd auth0-go-integration
go mod init auth0-go-integration

Now, let's grab the packages we'll need:

go get github.com/auth0-community/go-auth0
go get gopkg.in/square/go-jose.v2

Configuring Auth0 credentials

Head over to your Auth0 dashboard and grab your domain, client ID, and client secret. We'll use environment variables to keep these safe:

export AUTH0_DOMAIN=your-domain.auth0.com
export AUTH0_CLIENT_ID=your-client-id
export AUTH0_CLIENT_SECRET=your-client-secret

Pro tip: Consider using a .env file for local development. Just remember to add it to your .gitignore!

Implementing authentication

Let's create a simple function to handle authentication:

package main

import (
    "context"
    "log"
    "os"

    "gopkg.in/auth0-go.v5"
    "gopkg.in/auth0-go.v5/management"
)

func getManagementAPI() (*management.Management, error) {
    domain := os.Getenv("AUTH0_DOMAIN")
    clientID := os.Getenv("AUTH0_CLIENT_ID")
    clientSecret := os.Getenv("AUTH0_CLIENT_SECRET")

    return management.New(domain, management.WithClientCredentials(clientID, clientSecret))
}

This function will return an authenticated Management API client. Easy peasy!

Making API requests

Now that we're authenticated, let's make some API calls:

func main() {
    api, err := getManagementAPI()
    if err != nil {
        log.Fatalf("Failed to create management API client: %v", err)
    }

    // Get all users
    users, err := api.User.List()
    if err != nil {
        log.Fatalf("Failed to get users: %v", err)
    }

    for _, user := range users {
        log.Printf("User: %s", user.GetEmail())
    }
}

See? Making requests is a breeze with the management API client.

Error handling and logging

Always handle your errors gracefully. In the example above, we're using log.Fatalf for simplicity, but in a production app, you'd want more robust error handling and logging.

Testing the integration

Don't forget to test! Here's a quick example of how you might write a test:

func TestGetUsers(t *testing.T) {
    api, err := getManagementAPI()
    if err != nil {
        t.Fatalf("Failed to create management API client: %v", err)
    }

    users, err := api.User.List()
    if err != nil {
        t.Fatalf("Failed to get users: %v", err)
    }

    if len(users) == 0 {
        t.Error("Expected to get at least one user, got none")
    }
}

Best practices and security considerations

Always use environment variables or a secure vault for storing credentials
Implement proper token management and refresh mechanisms
Be mindful of rate limits when making API calls
Use HTTPS for all requests

Conclusion

And there you have it! You've just built an Auth0 API integration in Go. Pretty straightforward, right? Remember, this is just the beginning. There's so much more you can do with Auth0's API – from managing roles and permissions to handling multi-factor authentication.

Keep exploring, keep coding, and most importantly, keep securing your apps!

Resources

Happy coding, Gophers!