When running a web application on a non-standard port (like 5010), it's common practice to use Nginx as a reverse proxy to handle public-facing traffic on port 80/443. This provides several benefits:

• Hides your actual application server port
• Enables SSL termination
• Provides load balancing capabilities
• Allows serving multiple applications from single IP

Here's a minimal working configuration that proxies requests from port 80 to your application running on port 5010:

server {
    listen 80;
    server_name yourdomain.com www.yourdomain.com;

    location / {
        proxy_pass http://127.0.0.1:5010;
        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;
    }
}

Let's break down the key directives:

• proxy_pass: Defines the backend server address
• proxy_set_header: Ensures proper headers are forwarded
• X-Real-IP preserves the client's original IP
• X-Forwarded-Proto maintains the original protocol (http/https)

For production environments, consider adding these optimizations:

location / {
    proxy_pass http://127.0.0.1:5010;
    proxy_http_version 1.1;
    proxy_cache_bypass $http_upgrade;
    proxy_redirect off;
    
    # Timeout settings
    proxy_connect_timeout 60s;
    proxy_read_timeout 60s;
    proxy_send_timeout 60s;
    
    # Buffer settings
    proxy_buffers 16 32k;
    proxy_buffer_size 64k;
}

If your application uses WebSockets, add these directives:

location / {
    # ... existing directives ...
    
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
}

After making changes:

1. Test configuration: sudo nginx -t
2. Reload Nginx: sudo systemctl reload nginx
3. Check logs: tail -f /var/log/nginx/error.log

• 502 Bad Gateway: Check if backend service is running
• Connection refused: Verify firewall allows port 5010
• Headers missing: Ensure all proxy_set_header directives are present

Here's the minimal Nginx configuration needed to proxy requests from port 80 to your application running on port 5010:

server {
    listen 80;
    server_name yourdomain.com;

    location / {
        proxy_pass http://localhost:5010;
        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;
    }
}

proxy_pass: The core directive that forwards requests to your backend service.
proxy_set_header: Essential for preserving original request information when proxying.

1. SELinux/AppArmor blocking:
If requests aren't reaching your backend, check security modules:

sudo setsebool -P httpd_can_network_connect 1

2. Missing headers:
Without proper headers, your app might misbehave. Always include these:

proxy_set_header Connection '';
proxy_http_version 1.1;

For production environments, consider adding these optimizations:

proxy_buffering on;
proxy_buffer_size 4k;
proxy_buffers 8 16k;
proxy_busy_buffers_size 24k;
proxy_max_temp_file_size 2048m;

After making changes, always:

sudo nginx -t  # Test configuration
sudo systemctl reload nginx  # Apply changes

Here's a production-ready configuration handling both HTTP and HTTPS:

server {
    listen 80;
    server_name example.com www.example.com;
    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl;
    server_name example.com www.example.com;

    ssl_certificate /path/to/cert.pem;
    ssl_certificate_key /path/to/key.pem;

    location / {
        proxy_pass http://localhost:5010;
        # Standard proxy settings
        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;
        
        # Timeout settings
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
    }
}