Node.js Nginx Subdomain

subdomain

server {
    listen       80;
    server_name  www.subdomain.domain.com;
    return       301 subdomain.domain.com;
}

server {
    listen 80;

    server_name subdomain.domain.com;

    location / {
        proxy_pass http://127.0.0.1:3001; 
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
}