nginx.conf

events {
  worker_connections 1024;
}

http {
  include       mime.types;
  default_type  application/octet-stream;

  server {
    listen 80;

    # Serve React app
    location / {
      root /usr/share/nginx/html;
      try_files $uri /index.html;
    }

    # Proxy API requests to Node.js server
    location /api/ {
      proxy_pass http://server:4000/;
      
      # Add CORS headers
      add_header 'Access-Control-Allow-Origin' '*' always;
      add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
      add_header 'Access-Control-Allow-Headers' 'Authorization, Content-Type, Accept, Origin, X-Requested-With' always;
      
      # Handle preflight requests
      if ($request_method = OPTIONS) {
        add_header 'Access-Control-Allow-Origin' '*';
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
        add_header 'Access-Control-Allow-Headers' 'Authorization, Content-Type, Accept, Origin, X-Requested-With';
        return 204;  # No Content
      }
      
      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;
    }
  }
}