graceful-termination-container.sh

#!/bin/bash

trap 'echo "Caught interrupt! Gracefully delete 25s sleep to let another pod start..."; sleep 25; exit 0' INT

while true; do
    echo "Sleeping for 1h..."
    sleep 3600
done

If Bash is waiting for a command to complete and receives a signal for which a trap has been set, the trap will not be executed until the command completes.

Bash will interrupt wait, so one option is to background sleep and block on wait waiting for the sleep call to finish.

  sleep 3600 & wait $!

Technically, the background sleep call will still run to completion, but the exit in the trap takes care of that.