#!/bin/sh

noop() {
    while true; do
        # 2147483647 = max signed 32-bit integer
        # 2147483647 s ≅ 70 years
        sleep infinity || sleep 2147483647
    done
}

if [ ! -d /etc/opendkim/keys ]; then
    noop
elif [ -z "$(find /etc/opendkim/keys -type f ! -name .)" ]; then
    noop
else
    /usr/sbin/opendkim -D -f -x /etc/opendkim/opendkim.conf
fi