systemd is the de facto init system in most Linux distributions. After Node has been configured to run with systemd, it's possible to use the service command to manage it.

First of all, it needs a config file, let's create it. For Debian based distros, it will be in /etc/systemd/system/node.service

[Unit]
Description=My super nodejs app

[Service]
# set the working directory to have consistent relative paths
WorkingDirectory=/var/www/app

# start the server file (file is relative to WorkingDirectory here)
ExecStart=/usr/bin/node serverCluster.js

# if process crashes, always try to restart
Restart=always

# let 500ms between the crash and the restart
RestartSec=500ms

# send log tot syslog here (it doesn't compete with other log config in the app itself)
StandardOutput=syslog
StandardError=syslog

# nodejs process name in syslog
SyslogIdentifier=nodejs

# user and group starting the app
User=www-data
Group=www-data

# set the environement (dev, prod…)
Environment=NODE_ENV=production


[Install]
# start node at multi user system level (= sysVinit runlevel 3) 
WantedBy=multi-user.target

It's now possible to respectively start, stop and restart the app with:

service node start
service node stop
service node restart

To tell systemd to automatically start node on boot, just type: systemctl enable node.

That's all, node now runs as a dæmon.