https://discourse.nodered.org/t/auto-start-node-red-in-ubuntu/17627/6

Autostart Node-RED on Boot

To make Node-RED autostart when you boot or restart your Virtual Machine, you need to create a new systemd file for the nodered.service:

sudo nano /etc/systemd/system/nodered.service

Then, add the following (if you’re using root, you can leave the file as it is – otherwise comment the root and configure the non-root user option):

[Unit]
Description=Node-RED
After=syslog.target network.target

[Service]
ExecStart=/usr/local/bin/node-red --max-old-space-size=128 -v
Restart=on-failure
KillSignal=SIGINT

# log output to syslog as 'node-red'
SyslogIdentifier=node-red
StandardOutput=syslog

# non-root user to run as
#WorkingDirectory=/home/rui/
#User=rui
#Group=rui

# if using a root user
WorkingDirectory=/root/
User=root
Group=root

[Install]
WantedBy=multi-user.target

Your file should look like this, save it and exit (Ctrl+X, Y, Enter key).