Stop an idle GCP machine! This script assumes that you're connected through ssh with tmux to the machine, and when logging out usually the tmux session gets to the state detached. this script notices that and shuts down the machine

gistfile1.txt

#!/bin/bash

# Initial timeout in seconds to wait before checking the SSH sessions
SLEEP_DURATION=300 # 5 minutes

# Additional wait time for the final check
FINAL_CHECK_DELAY=600 # 10 minutes

# Function to check tmux sessions
check_tmux_sessions() {
    if tmux list-sessions &> /dev/null; then
        # tmux is running, now check for detached sessions
        detached_sessions=$(tmux list-sessions | grep -vc attached)
        total_sessions=$(tmux list-sessions | wc -l)
        if [ "$detached_sessions" -eq "$total_sessions" ]; then
            # All tmux sessions are detached
            return 0
        else
            # There are attached tmux sessions
            return 1
        fi
    else
        # tmux is not running
        return 0
    fi
}

# Main loop
while true; do
    # Check for active SSH sessions excluding the script's own session
    if check_tmux_sessions; then
        echo "All tmux sessions are detached. Starting final check timer for $FINAL_CHECK_DELAY seconds."
        sleep $FINAL_CHECK_DELAY
        # Perform the check again after the delay
        if check_tmux_sessions; then
            echo "Final check passed. All tmux sessions are still detached. Initiating shutdown."
            sudo shutdown -h now
            exit
        else
            echo "Final check failed. There are attached tmux sessions now."
        fi
    else
        echo "There are attached tmux sessions."
    fi
    sleep $SLEEP_DURATION
done