nginx-ldap-auth-service

nginx-ldap-auth-service is a high-performance authentication daemon built with FastAPI. It provides an authentication bridge between nginx and LDAP or Active Directory servers, including support for Duo MFA.

It works in conjunction with nginx's ngx_http_auth_request_module to provide a seamless login experience for your web applications.

Features

• LDAP/Active Directory Integration: Authenticate users against any LDAP-compliant server or Microsoft Active Directory.
• FastAPI Powered: High performance, asynchronous connection management, and modern implementation.
• Login Form & Session Management: Built-in login form and session handling.
• Duo MFA Support: Optional Duo Multi-Factor Authentication workflow.
• Flexible Session Backends: Support for in-memory or Redis-based sessions for high availability.
• Authorization Filters: Restrict access based on LDAP search filters (e.g., group membership).
• Docker Ready: Easily deployable as a sidecar container.
• Monitoring Endpoints: Built-in /status and /status/ldap health checks.

Installation

via pip

pip install nginx-ldap-auth-service

via uv

uv tool install nginx-ldap-auth-service

via pipx

pipx install nginx-ldap-auth-service

via Docker

docker pull caltechads/nginx-ldap-auth-service:latest

Quick Start (Docker Compose)

Create a docker-compose.yml file:

services:
  nginx-ldap-auth-service:
    image: caltechads/nginx-ldap-auth-service:latest
    environment:
      - LDAP_URI=ldap://ldap.example.com
      - LDAP_BASEDN=dc=example,dc=com
      - LDAP_BINDDN=cn=admin,dc=example,dc=com
      - LDAP_PASSWORD=secret
      - SECRET_KEY=your-session-secret
      - CSRF_SECRET_KEY=your-csrf-secret
    ports:
      - "8888:8888"

Run with:

docker-compose up -d

Configuration

The service can be configured via environment variables, command-line arguments, or Nginx headers.

Required Environment Variables

Variable	Description
LDAP_URI	URL of the LDAP server (e.g., ldap://localhost)
LDAP_BINDDN	DN of a privileged user for searches
LDAP_PASSWORD	Password for the LDAP_BINDDN user
LDAP_BASEDN	Base DN for user searches
SECRET_KEY	Secret key for session encryption
CSRF_SECRET_KEY	Secret key for CSRF protection

Important Optional Variables

• DUO_ENABLED: Set to True to enable Duo MFA (Note that you must also define all the DUO_* configs also)
• SESSION_BACKEND: memory (default) or redis.
• LDAP_AUTHORIZATION_FILTER: LDAP filter to restrict access.
• COOKIE_NAME: Name of the session cookie (default: nginxauth).

For a full list of configuration options, see the Configuration Documentation.

Nginx Integration

To use the service with Nginx, configure your location blocks to use auth_request:

location / {
    auth_request /check-auth;
    error_page 401 =200 /auth/login?service=$request_uri;
    # ... your application config ...
}

location /auth {
    proxy_pass http://nginx-ldap-auth-service:8888/auth;
    proxy_set_header X-Cookie-Name "nginxauth";
    proxy_set_header X-Cookie-Domain "localhost";
    proxy_set_header X-Proto-Scheme $scheme;
    proxy_set_header Host $host;
    proxy_set_header Cookie $http_cookie;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for
}

location /check-auth {
    internal;
    proxy_pass http://nginx-ldap-auth-service:8888/check;
    proxy_pass_request_headers off;
    proxy_pass_request_body off;
    proxy_set_header Content-Length "";
    proxy_ignore_headers "Set-Cookie";
    proxy_hide_header "Set-Cookie";
    proxy_cache auth_cache;
    proxy_cache_valid 200 10m;
    proxy_set_header X-Cookie-Name "nginxauth";
    proxy_set_header Cookie nginxauth=$cookie_nginxauth;
    proxy_set_header X-Cookie-Domain "localhost";
    proxy_cache_key "$http_authorization$cookie_nginxauth";
}

For detailed Nginx configuration examples, including caching and Duo MFA headers, see the Nginx Configuration Guide.

Documentation

The full documentation is available at https://nginx-ldap-auth-service.readthedocs.io.

License

This project is licensed under the terms of the LICENSE.txt file.