server-scripts/script-system-scheduled-restart

#!/usr/bin/env bash
# Update and restart the system
# Copyright 2021 Bryan C. Roessler

parent="${BASH_SOURCE[0]}"
parent=${parent%/*}

[[ -f $parent/script-functions ]] && . "$parent"/script-functions || exit 1

is_root

[[ $# -eq 0 ]] && time='*-*-* 01:30:00' # 1:30AM
[[ $# -gt 1 ]] && time="$*"

script-system-update

ask_ok "Set a scheduled reboot for $time?" || exit 1

cat <<- EOF > "/usr/lib/systemd/system/scheduled-reboot.timer"
[Unit]
Description=Scheduled reboot

[Timer]
OnCalendar=$time
Unit=reboot.target

[Install]
WantedBy=timers.target
EOF

systemctl daemon-reload
systemctl start scheduled-reboot.timer

# Current date
dt=$(date '+%d/%m/%Y %H:%M:%S');

message="System restart scheduled for $time. The current time is $dt. Make sure all changes are saved."

# Graphical notification
IFS=$'\n'
for LINE in $(w -hs); do
    USER=$(echo "$LINE" | awk '{print $1}')
    USER_ID=$(id -u "$USER")
    DISP_ID=$(echo "$LINE" | awk '{print $8}')
    sudo -u "$USER" DISPLAY="$DISP_ID" DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/"$USER_ID"/bus notify-send "$message" --icon=dialog-warning
done

# Wall notification
wall -n "$message"

exit $?