In previous Linux versions, startup scripts can simply be enabled by linking a script into the /etc/rc.d/ directory, and voila:

startupScript=/etc/init.d/startupScript
ln -s $startupScript /etc/rc.d/

However, recent versions of major branches such as Debian require that a script be LSB compliant to be triggered by the system upon booting; hence, a more universal method to edit startup routines on any Linux machine is to configure cron as shown in this example:

startupScript=/ect/init.d/startVncSessions.sh
cat <<EOF >  $startupScript
#!/bin/bash
# /etc/init.d/startVncSessions.sh
# Manually set users and session IDs
declare -A users=(
	["einie"]=1
	["minie"]=2
	["maynie"]=3
	["moe"]=4
	["wiwi"]=5
	)

for k in "${!users[@]}"
do
	username=$k
	sessionId=${users[$k]}
	#printf "%s\n" "key: $username value: $sessionId"
	sudo -H -u $username bash -c "vncserver -kill :$sessionId"	
	sudo rm -f /tmp/.X$sessionId-lock
	sudo rm -f /tmp/.X11-unix/X$sessionId
	sudo -H -u $username bash -c "vncserver :$sessionId -geometry 1920x1080 -depth 15 -pixelformat rgb565"
	sudo -H -u $username bash -c "websockify -D --web=/usr/share/novnc/ --cert=/etc/ssl/novnc.pem 908$sessionId localhost:590$sessionId"
done
EOF

# Set script to run at startup
chmod a+x $startupScript
chmod 777 $startupScript # optional: this is to give everyone full access, including editing rights

# Put it in cron
crontab -e
### add this line ###
@reboot /bin/bash -c '/ect/init.d/startVncSessions.sh' &