How to Configure Azure NGINXaaS as a Reverse Proxy to Your Local Server

NGINX as a Service for Azure (NGINXaaS) is a managed solution that brings the power of NGINX directly into the Microsoft Azure ecosystem. Whether you need to optimize traffic routing, secure access to on-premise systems, or scale cloud applications efficiently, Azure’s NGINXaaS makes it possible with minimal management overhead.

In this guide, you’ll learn how to configure Azure NGINXaaS as a reverse proxy to route incoming requests to one of your local or internal servers.

What Is NGINX as a Service for Azure?

NGINXaaS for Azure is a fully managed offering built on NGINX Plus, the enterprise edition of NGINX. It provides all the capabilities of an advanced application delivery controller — including load balancing, caching, and reverse proxy — without requiring you to maintain the underlying infrastructure.

NGINXaaS integrates seamlessly with Azure tools such as:

• Microsoft Entra (Azure AD) for identity and access management
• Azure Key Vault for SSL/TLS certificate storage
• Azure Monitor for performance and availability insights

This makes it ideal for hybrid or multi-cloud setups where some services run locally while others reside in the cloud.

Step 1: Create and Connect to an Azure Virtual Machine

Before configuring your reverse proxy, you’ll need a Linux-based virtual machine in Azure.

1. Create a VM from the Azure Portal using Ubuntu or Debian.
2. Open port 80 and 443 in the Network Security Group (NSG) to allow HTTP and HTTPS traffic.
3. Connect to the VM via SSH:

   ssh youruser@your_vm_ip
   

   Or, if you’re using key-based authentication:

   ssh -i /path/to/your/key.pem youruser@your_vm_ip
   

When prompted, confirm the host fingerprint and log in to the server.

Step 2: Install NGINX

Once connected to your Azure VM, install NGINX with:

sudo apt update -y
sudo apt install nginx -y

Verify the service is running:

sudo systemctl status nginx

If NGINX is active, you can visit your public VM IP (for example, http://20.xxx.xxx.xxx) to confirm the default welcome page is displayed.

Step 3: Set Up Your Local Upstream Application

The “upstream” server is the local or internal application that NGINX will proxy requests to.
This could be:

• A web server running on your local network (via VPN or private IP)
• An application container listening on a port such as 8080
• A private API or microservice

Ensure your application is reachable from the NGINX host. For example:

curl http://localhost:8080

If it responds, you’re ready to configure NGINX.

Step 4: Configure NGINX as a Reverse Proxy

Open the default NGINX configuration file:

sudo nano /etc/nginx/sites-available/default

Inside the server block, locate the location / section and modify it like this:

location / {
    proxy_pass http://localhost:8080;
    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;
}

Then test and reload NGINX:

sudo nginx -t
sudo systemctl reload nginx

Now all traffic to your Azure VM (port 80) will be forwarded to your local server at port 8080.

Step 5: Secure and Optimize Your Proxy

To enhance security and performance, add the following headers and options inside the same location block:

add_header X-Frame-Options "SAMEORIGIN";
add_header X-XSS-Protection "1; mode=block";
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload";
add_header Referrer-Policy "no-referrer-when-downgrade";
proxy_buffering off;

To enable HTTPS, upload your SSL/TLS certificates to Azure Key Vault and configure NGINXaaS to use them.

Step 6: NGINXaaS Configuration Limits and Best Practices

When deploying NGINXaaS in Azure, note that some configuration directives are restricted for security and compatibility reasons. For example, proxy_bind, debug_points, and ssl_engine are not supported.

Only use the allowed directories for your configuration (/etc/nginx, /var/www, /opt, /srv, and /tmp). Attempts to access other paths may result in 5xx errors.

NGINXaaS allows you to upload your configuration through the Azure Portal, CLI, or ARM templates. For production workloads, consider version-controlling your config and deploying it via Terraform or CI/CD pipelines.

Step 7: Validate and Monitor Your Setup

Once your reverse proxy is up and running:

• Test your endpoint in the browser or using curl:

  curl -I http://your-nginx-fqdn
  

• Confirm that the response headers indicate the NGINX proxy.
• Use Azure Monitor to track uptime, response time, and errors.

Why Use Azure NGINXaaS for Reverse Proxying?

1. Simplified Management – You don’t need to maintain the NGINX instance manually.
2. Scalability – Easily scale up as your application traffic grows.
3. Security Integration – Works seamlessly with Azure security services.
4. Hybrid Flexibility – Ideal for bridging on-premise and cloud systems.

Conclusion

By configuring Azure NGINXaaS as a reverse proxy, you gain a reliable and efficient bridge between your cloud and on-premise infrastructure. The setup process is straightforward — from creating the Azure VM and installing NGINX to defining a simple proxy_pass directive.

Whether you’re managing APIs, web applications, or IoT services, Azure’s NGINXaaS provides a flexible, secure, and scalable way to route traffic exactly where you need it.