nginx.conf

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

events {
    worker_connections 1024;
}

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

    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for"';

    access_log /var/log/nginx/access.log main;

    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;

    # Upstream definitions
    # API Gateway - Multiple instances with load balancing
    upstream api_gateway {
        # Round-robin load balancing across 3 instances
        # Docker DNS (api-gateway:3000) automatically resolves to all 3 containers
        server api-gateway:3000;
        
        # Keep connections alive for better performance
        keepalive 32;
    }

    upstream tracking_service {
        server tracking-service:3005;
    }

    upstream auth_service {
        server auth-service:3001;
    }

    upstream order_service {
        server order-service:3002;
    }

    upstream restaurant_service {
        server restaurant-service:3003;
    }

    upstream delivery_service {
        server delivery-service:3004;
    }

    # Rate limiting zones
    limit_req_zone $binary_remote_addr zone=general:10m rate=10r/s;
    limit_req_zone $binary_remote_addr zone=auth:10m rate=5r/s;
    limit_req_zone $binary_remote_addr zone=order:10m rate=20r/s;

    # Main server block
    server {
        listen 80 default_server;
        server_name _;

        # API Gateway - Default routing (3 instances with load balancing)
        location / {
            proxy_pass http://api_gateway;
            proxy_http_version 1.1;
            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_set_header Connection "";
            
            # Connection pooling for better performance
            proxy_connect_timeout 60s;
            proxy_send_timeout 60s;
            proxy_read_timeout 60s;
            
            # Buffering
            proxy_buffering on;
            proxy_buffer_size 4k;
            proxy_buffers 8 4k;
            
            limit_req zone=general burst=20 nodelay;
        }

        # WebSocket endpoint for tracking
        location /tracking {
            proxy_pass http://tracking_service;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }

        # Auth routes
        location /auth/ {
            proxy_pass http://auth_service/;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            limit_req zone=auth burst=10 nodelay;
        }

        # Order routes
        location /orders/ {
            proxy_pass http://order_service/;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            limit_req zone=order burst=30 nodelay;
        }

        # Restaurant routes
        location /restaurants/ {
            proxy_pass http://restaurant_service/;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }

        # Delivery routes
        location /delivery/ {
            proxy_pass http://delivery_service/;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }

        # Health check
        location /health {
            access_log off;
            return 200 "healthy\n";
            add_header Content-Type text/plain;
        }
    }
}