Reverse Proxy configuration using NGINX

Introduction

This guide explains how to configure NGINX as a reverse proxy for Defguard's components (Core and Proxy). The reverse proxy acts as an intermediary between users and Defguard services, handling HTTPS requests, routing internal gRPC communication, and ensuring encrypted connections between all components.

To provide HTTPS encryption, this guide also uses Certbot, a free, open-source tool from the Let’s Encrypt project. Certbot automatically issues and renews SSL/TLS certificates, allowing you to secure your Defguard domains without manual certificate management.

Installing NGINX and Certbot

To install and prepare NGINX with Let’s Encrypt certificates:

apt install nginx certbot
systemctl enable nginx.service
systemctl start nginx.service

Disable the default configuration to avoid conflicts:

unlink /etc/nginx/sites-enabled/default

Obtaining SSL Certificates

Before configuring NGINX, issue valid SSL certificates for your domains. In this example we use:

• Core: my-server.defguard.net

• Enrollment (Proxy): enroll.defguard.net

Generate certificates with Certbot:

certbot certonly \
    --non-interactive \
    --agree-tos \
    --standalone \
    --email [email protected] \
    -d my-server.defguard.net \
    -d enroll.defguard.net

Certbot will generate certificate in fullchain.pem and privkey.pem in the following paths:

/etc/letsencrypt/live/my-server.defguard.net
/etc/letsencrypt/live/enroll.defguard.net

Defguard Core NGINX configuration

Create a new configuration file for the Core service:

/etc/nginx/sites-available/my-server.defguard.net.conf

upstream defguard {
    server 127.0.0.1:8000;
}

upstream defguard-grpc {
    server 127.0.0.1:50055;
}

server {
    listen 443 ssl http2;
    server_name my-server.defguard.net;
    access_log /var/log/nginx/defguard.log;
    error_log /var/log/nginx/defguard.e.log;

    ssl_certificate /etc/letsencrypt/live/my-server.defguard.net/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/my-server.defguard.net/privkey.pem;
    ssl_trusted_certificate /etc/letsencrypt/live/my-server.defguard.net/fullchain.pem;

    client_max_body_size 128M;

    location / {
        proxy_pass          http://defguard;
        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_http_version  1.1;
        proxy_set_header    Upgrade             $http_upgrade;
        proxy_set_header    Connection          "upgrade";
    }
}

server {
    listen 444 ssl http2;
    server_name my-server.defguard.net;
    access_log /var/log/nginx/defguard-grpc.log;
    error_log /var/log/nginx/defguard-grpc.e.log;

    ssl_certificate /etc/letsencrypt/live/my-server.defguard.net/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/my-server.defguard.net/privkey.pem;

    client_max_body_size 200m;

    location / {
        grpc_pass grpc://defguard-grpc;
    }
}

Enable the configuration and reload NGINX:

ln -s /etc/nginx/sites-available/my-server.defguard.net.conf /etc/nginx/sites-enabled/my-server.defguard.net.conf

systemctl reload nginx.service

To verify, run:

curl https://my-server.defguard.net/api/v1/health
# Expected output:
alive

If you use this simple setup and run all services on one server, you can use NGINX access restrictions for securing core and allowing to access the my-server.defguard.net only to selected networks - blocking the direct access from the Internet.

Defguard Proxy (Enrollment Service) NGINX configuration

The Proxy service exposes APIs for enrollment, remote onboarding, and desktop client configuration. Create its NGINX configuration file:

/etc/nginx/sites-available/enroll.defguard.net.conf

upstream defguard-proxy {
    server 127.0.0.1:8080;
}

upstream proxy-grpc {
    server 127.0.0.1:50051;
}

server {
    listen 443 ssl http2;
    server_name enroll.defguard.net;
    access_log /var/log/nginx/enroll.log;
    error_log /var/log/nginx/enroll.e.log;

    ssl_certificate /etc/letsencrypt/live/enroll.defguard.net/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/enroll.defguard.net/privkey.pem;

    client_max_body_size 200m;

    location / {
        proxy_http_version 1.1;
        proxy_pass         http://defguard-proxy;
        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   Upgrade $http_upgrade;
        proxy_set_header   Connection "upgrade";
        proxy_set_header   X-Forwarded-Proto $scheme;
        proxy_read_timeout 86400s;
        proxy_send_timeout 86400s;
    }
}

server {
    listen 444 ssl http2;
    server_name enroll.defguard.net;
    access_log /var/log/nginx/enroll-grpc.log;
    error_log /var/log/nginx/enroll-grpc.e.log;

    ssl_certificate /etc/letsencrypt/live/enroll.defguard.net/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/enroll.defguard.net/privkey.pem;

    client_max_body_size 200m;

    location / {
        grpc_pass grpc://proxy-grpc;
        grpc_socket_keepalive on;
        grpc_read_timeout 3000s;
        grpc_send_timeout 3000s;
        grpc_next_upstream_timeout 0;

        proxy_request_buffering off;
        proxy_buffering off;
        proxy_connect_timeout 3000s;
        proxy_send_timeout 3000s;
        proxy_read_timeout 3000s;
        proxy_socket_keepalive on;

        keepalive_timeout 90s;
        send_timeout 90s;

        client_body_timeout 3000s;
    }
}

Enable and restart NGINX:

ln -s /etc/nginx/sites-available/enroll.defguard.net.conf /etc/nginx/sites-enabled/enroll.defguard.net.conf

systemctl restart nginx.service

Security Recommendations

• Only expose HTTPS ports (443) for web access.

• Do not expose internal gRPC ports (444, 50051, 50055) directly to the Internet.

Summary

After completing the configuration:

• Defguard Core is available at https://my-server.defguard.net

• Enrollment and onboarding services are available at https://enroll.defguard.net

• Both services are secured with SSL and reverse-proxied through NGINX.