Node.js Application

Basic Node.js Proxy

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://localhost:3000;
        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;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_cache_bypass $http_upgrade;
    }
}

Production Configuration

upstream nodejs {
    server 127.0.0.1:3000;
    keepalive 64;
}

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

server {
    listen 443 ssl http2;
    server_name example.com;

    # SSL
    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;
    include snippets/ssl-params.conf;

    # Security headers
    include snippets/security-headers.conf;

    # Logs
    access_log /var/log/nginx/example.com.access.log;
    error_log /var/log/nginx/example.com.error.log;

    # Static files
    location /static/ {
        alias /var/www/example.com/static/;
        expires 30d;
        add_header Cache-Control "public, immutable";
    }

    # API proxy
    location / {
        proxy_pass http://nodejs;
        proxy_http_version 1.1;

        # Headers
        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;

        # WebSocket support
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";

        # Keepalive
        proxy_set_header Connection "";

        # Timeouts
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;

        # Buffering
        proxy_buffering on;
        proxy_buffer_size 4k;
        proxy_buffers 8 4k;
    }

    # Health check endpoint
    location /health {
        proxy_pass http://nodejs/health;
        access_log off;
    }
}

With Socket.io

# WebSocket upgrade map
map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
}

server {
    # ... SSL config ...

    location / {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_set_header Host $host;
    }

    location /socket.io/ {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;

        # Longer timeout for WebSocket
        proxy_read_timeout 86400s;
        proxy_send_timeout 86400s;
    }
}

Express Trust Proxy

// In your Express app
const app = express();

// Trust first proxy (nginx)
app.set('trust proxy', 1);

// Now req.ip gives real client IP
app.get('/', (req, res) => {
    console.log(req.ip);  // Real client IP
    console.log(req.protocol);  // https (from X-Forwarded-Proto)
});