[Unit]
Description=My app
After=network.target

[Service]
ExecStart=/var/www/myapp/app.js
Restart=always
User=nobody
# Debian/Ubuntu uses 'nogroup'
# RHEL/Fedora uses 'nobody'
Group=nogroup
Environment=PATH=/usr/bin:/usr/local/bin
Environment=NODE_ENV=production
WorkingDirectory=/var/www/myapp

[Install]
WantedBy=multi-user.target