signal-listener.sh

#!/bin/sh
# A wrapper around /entrypoint.sh to trap the SIGINT signal (Ctrl+C) and forwards it to the background daemon
# In other words : traps SIGINT and SIGTERM signals and forwards them to the child process as SIGTERM signals
# https://medium.com/@manish_demblani/docker-container-uncaught-kill-signal-d5ed22698293

signalListener() {
    "$@" &
    pid="$!"
    trap "echo 'Stopping PID $pid'; kill -SIGTERM $pid; caddy stop" SIGINT SIGTERM

    # A signal emitted while waiting will make the wait command return code > 128
    # Let's wrap it in a loop that doesn't end before the process is indeed stopped
    while kill -0 $pid > /dev/null 2>&1; do
        wait
    done
}

signalListener slides-preview.sh $@