Authentik Forward Auth Setup With Zoraxy: A Troubleshooting Guide

by Alex Johnson 66 views

Introduction

This article addresses the challenges encountered while setting up forward authentication with Authentik in Zoraxy. The user is transitioning from Nginx Proxy Manager and seeks guidance on configuring Authentik, a popular open-source identity provider, with Zoraxy, a modern edge proxy. This guide aims to provide a comprehensive walkthrough, covering potential issues and solutions for a successful integration.

Understanding Forward Authentication

Before diving into the specifics, let's clarify what forward authentication is and why it's useful. Forward authentication, also known as external authentication, allows a reverse proxy like Zoraxy to delegate the authentication process to an external service, such as Authentik. This approach centralizes authentication logic, enhances security, and simplifies management, especially in complex environments with multiple applications and services.

Benefits of Forward Authentication

  • Centralized Authentication: Manage user access and policies in one place.
  • Enhanced Security: Leverage advanced authentication features like multi-factor authentication (MFA).
  • Simplified Management: Reduce configuration complexity and streamline user onboarding/offboarding.
  • Improved User Experience: Provide a consistent login experience across all applications.

Problem Description

The user reports difficulties configuring forward authentication in Zoraxy with an Authentik instance. They have defined multiple applications in Authentik that rely on forward authentication. The primary issue is determining the correct URL to use within Zoraxy to communicate with Authentik's forward authentication endpoint. Several URLs were attempted, but none resulted in successful authentication.

Troubleshooting Steps and Solutions

Let's explore the attempted URLs and provide solutions for each:

1. https://auth.mydomain.dev/outpost.goauthentik.io

This URL is often associated with Authentik's older outpost integration method. While it might have worked in previous versions, it's not the recommended approach for forward authentication. This endpoint is typically used by the goauthentik.io outpost proxy, not a generic forward auth setup. Therefore, it's unlikely to work directly with Zoraxy.

Solution: Avoid using this URL for forward authentication. Focus on the dedicated forward auth endpoints provided by Authentik.

2. https://auth.mydomain.dev/authz/forward-auth

This URL seems like a plausible candidate for the forward authentication endpoint. However, the error message "The request method is invalid for the requested resource" indicates that the HTTP method used by Zoraxy to access this endpoint is not supported. Authentik's forward auth endpoint typically expects a GET request with specific headers containing user information.

Solution:

  • Verify HTTP Method: Ensure that Zoraxy is sending a GET request to this endpoint.
  • Check Request Headers: Confirm that Zoraxy is including the necessary headers, such as X-Forwarded-Email, X-Forwarded-User, X-Forwarded-Groups, etc. These headers are crucial for Authentik to identify the user.
  • Review Authentik Documentation: Consult Authentik's documentation for the exact header requirements and expected response format.

3. https://auth.mydomain.dev/api/authz/forward-auth

This URL is similar to the previous one, but it explicitly includes /api/. The same error message suggests the same underlying issue: an incorrect HTTP method or missing/incorrect headers.

Solution: Apply the same solutions as for the previous URL. Double-check the HTTP method and request headers.

4. https://auth.mydomain.dev/

This URL points to the root of the Authentik instance. While it might display the Authentik login page, it's not the correct endpoint for forward authentication. Forward authentication requires a specific endpoint that processes the incoming request and returns a decision based on the user's authentication status.

Solution: Avoid using the root URL. Focus on the dedicated forward auth endpoints.

Recommended Configuration Steps

Here’s a step-by-step guide to correctly configure forward authentication with Authentik in Zoraxy:

  1. Authentik Configuration:
    • Create an Application: In Authentik, create an application that represents the service you want to protect with forward authentication (e.g., adguard.mydomain.dev).
    • Create a Provider: Create a provider for the application. Choose the "Forward Auth (Single Host)" provider type.
    • Configure Provider Settings:
      • Name: Give the provider a descriptive name.
      • Forward Auth URL: This is the URL that Zoraxy will use to communicate with Authentik. It typically follows the format: https://auth.mydomain.dev/authz/forward-auth.
      • Session Cookie Domain: Set the domain for the session cookie (e.g., mydomain.dev).
      • Internal Hostname: The internal hostname of the service being protected.
    • Define Policies (Optional): Create policies to define access rules based on user groups, roles, or other criteria.
  2. Zoraxy Configuration:
    • Add Forward Auth: In Zoraxy, navigate to the service you want to protect (e.g., adguard.mydomain.dev).
    • Enable Forward Auth: Enable the forward authentication feature.
    • Set Forward Auth URL: Enter the same URL you configured in Authentik's provider settings (https://auth.mydomain.dev/authz/forward-auth).
    • Configure Headers: Ensure that Zoraxy is sending the necessary headers to Authentik. These headers typically include:
      • X-Forwarded-Email: User's email address.
      • X-Forwarded-User: Username.
      • X-Forwarded-Groups: Comma-separated list of user groups.
      • X-Forwarded-For: The client IP address.
      • X-Forwarded-Proto: The protocol used to connect to Zoraxy (e.g., http or https).
    • Test Configuration: Access the protected service (adguard.mydomain.dev) to verify that authentication is working correctly. You should be redirected to the Authentik login page if you are not already authenticated.

Addressing Networking Setup

The user mentions using a NAT router and having a DNS record for *.mydomain.dev pointing to the Zoraxy IP address. This setup is generally compatible with forward authentication, but it's essential to ensure that the NAT router is correctly forwarding traffic to the Zoraxy instance.

Potential Issues

  • Port Forwarding: Verify that the necessary ports (e.g., 80 and 443) are forwarded from the NAT router to the Zoraxy instance.
  • DNS Resolution: Ensure that the DNS record for *.mydomain.dev is correctly resolving to the public IP address of the NAT router.
  • Firewall Rules: Check that the firewall on the NAT router is not blocking traffic to or from the Zoraxy instance.

Additional Considerations

  • Zoraxy Version: While not explicitly mentioned, ensure you are using a recent version of Zoraxy that supports forward authentication correctly. Refer to the Zoraxy documentation for compatibility information.
  • Logs: Examine the logs of both Zoraxy and Authentik for any error messages or clues about the cause of the authentication failure. Enable debug logging if necessary.
  • TLS/SSL: Ensure that TLS/SSL certificates are correctly configured for both Zoraxy and Authentik to secure the communication between them.
  • Cookie Configuration: Double-check the cookie settings in both Zoraxy and Authentik to ensure they are compatible and do not conflict with each other.

Example Configuration Snippet (Conceptual)

While the exact configuration steps might vary depending on the specific Zoraxy version and Authentik setup, here's a conceptual example of how the forward authentication configuration might look:

Zoraxy Configuration (Example):

location / {
    auth_request /auth;
    auth_request_set $auth_status $upstream_status;
    proxy_pass http://backend;

    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;

    # Headers for Authentik
    proxy_set_header X-Forwarded-Email $upstream_http_x_forwarded_email;
    proxy_set_header X-Forwarded-User $upstream_http_x_forwarded_user;
    proxy_set_header X-Forwarded-Groups $upstream_http_x_forwarded_groups;

    proxy_pass_request_body off;
    proxy_set_header Content-Length "";
}

location = /auth {
    proxy_pass https://auth.mydomain.dev/authz/forward-auth;
    proxy_pass_request_body off;
    proxy_set_header Content-Length "";

    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;

    # Return 200 if authentication is successful
    proxy_pass_request_headers on;
    proxy_set_header Content-Length "";
    proxy_ignore_headers X-Accel-Redirect;
    proxy_intercept_errors off;
}

Authentik Forward Auth Provider Configuration (Example):

  • Name: Zoraxy Forward Auth
  • Forward Auth URL: https://auth.mydomain.dev/authz/forward-auth
  • Session Cookie Domain: mydomain.dev
  • Internal Hostname: backend

Conclusion

Setting up forward authentication with Authentik in Zoraxy requires careful configuration of both systems. By understanding the correct URLs, HTTP methods, and header requirements, you can successfully integrate Authentik with Zoraxy and secure your applications. Remember to consult the documentation for both Authentik and Zoraxy for the most accurate and up-to-date information. By following these steps, you should be well on your way to a secure and streamlined authentication process. If issues persist, examine the logs and double-check all configurations for any discrepancies.

For more information on Authentik and its features, visit the Authentik Documentation. This resource provides comprehensive details on configuring and managing Authentik for various use cases.