This script creates a systemd timer that shuts down a machine if there are no active connections to it. Default is 30 minutes. Must run as root.

shutdown-when-idle.sh

#!/bin/bash
## Colors
BOLD=$(tput bold)
NOCOLOR=$(tput sgr0)
RED=$(tput setaf 1)
GREEN=$(tput setaf 2)
YELLOW=$(tput setaf 3)
BLUE=$(tput setaf 4)
PURPLE=$(tput setaf 5)
CYAN=$(tput setaf 6)
WHITE=$(tput setaf 7)
BLACK=$(tput setaf 8)
BG_YELLOW=$(tput setab 3)
BOLD_RED=($BOLD$RED)

# Formatting
DIV="$BLACK---------------------------------------------------------------------$NOCOLOR"
TICK="$NOCOLOR[$GREEN+$NOCOLOR] "
TICK_MOVE="$NOCOLOR[$GREEN~>$NOCOLOR]"
TICK_BACKUP="$NOCOLOR[$GREEN<~$NOCOLOR] "
TICK_INPUT="$NOCOLOR[$YELLOW!$NOCOLOR] "
TICK_ERROR="$NOCOLOR[$RED!$NOCOLOR] "
TICK_INFO="$NOCOLOR[$YELLOW-$NOCOLOR] "


# Check if the script is running as root
if [[ $EUID -ne 0 ]]; then
  echo $TICK_ERROR"This script must be run as root. Please use sudo."
  exit 1
fi


# Create the shutdown script
echo $TICK"Making$BLUE /usr/local/bin/shutdown-if-no-logged-users.sh"$NOCOLOR
cat << 'EOF' > /usr/local/bin/shutdown-if-no-logged-users.sh
#!/bin/bash

#Get the number of logged-in users (excluding root and system users).
loggedInUsers=$(who | grep -v -E 'root|systemd-|dbus' | wc -l)

if [[ $loggedInUsers -eq 0 ]]; then
  # No users logged in, shut down the VM.
  shutdown -h now
else
  echo "Users are logged in"
fi

EOF

# Make the script executable
echo $TICK"Making$BLUE /usr/local/bin/shutdown-if-no-logged-users.sh"$NOCOLOR
chmod +x /usr/local/bin/shutdown-if-no-logged-users.sh

 #Create the systemd service file
echo $TICK"Creating$BLUE /etc/systemd/system/are-users-logged.service"$NOCOLOR
cat << 'EOF' > /etc/systemd/system/are-users-logged.service
[Unit]
Description=Check for logged-in users and shutdown if idle

[Service]
Type=oneshot
ExecStart=/usr/local/bin/shutdown-if-no-logged-users.sh

[Install]
WantedBy=multi-user.target
EOF

# Create the systemd timer file
echo $TICK"Creating$BLUE /etc/systemd/system/are-users-logged.timer"$NOCOLOR
cat << 'EOF' > /etc/systemd/system/are-users-logged.timer
[Unit]
Description=Run are-users-logged.service every 30 minutes

[Timer]
OnBootSec=30min
OnUnitActiveSec=30min

[Install]
WantedBy=timers.target
EOF

# Enable and start the timer
echo $TICK"Enabling$BLUE are-users-logged.timer"$NOCOLOR
systemctl enable are-users-logged.timer
echo $TICK"Starting$BLUE are-users-logged.timer"$NOCOLOR
systemctl start are-users-logged.timer

echo $TICK$GREEN"VM shutdown service installed and activated."