check_pki_dir() {
	if [ -z "$ICINGA_CA" ]; then
		echo "Please set the ICINGA_CA environment variable to the path for your Icinga CA." >&2
		echo "e.g.: export ICINGA_CA=\"$HOME/icinga-ca\"" >&2
		exit 1
	fi

	if [ ! -d "$ICINGA_CA" ]; then
		echo "The path you specified in the ICINGA_CA environment variable ($ICINGA_CA) does not exist or is not a directory." >&2
		exit 1
	fi
}