#!/bin/sh

set -e

PATH=/sbin:/bin:/usr/sbin:/usr/bin

# This is a heuristic:  The idea is that if a static interface is brought
# up, that is a major event, and we can put in some extra effort to fix
# the system time.  Feel free to change this, especially if you regularly
# bring up new network interfaces.
if [ "$METHOD" = static ]; then
	OPTS="-b"
fi

if [ "$METHOD" = loopback ] || [ "$METHOD" = none ]; then
	exit 0
fi

# only run on primary network interface
if [ "$IFACE" != {{ ansible_default_ipv4.interface }} ]; then
	exit 0
fi

# Check whether ntpdate was removed but not purged; it's useless to wait for
# it in that case.
if [ ! -x /usr/sbin/ntpdate-debian ] && [ -d /usr/sbin ]; then
	exit 0
fi

(

# This is for the case that /usr will be mounted later.
if [ -r /lib/udev/hotplug.functions ]; then
	. /lib/udev/hotplug.functions
	wait_for_file /usr/sbin/ntpdate-debian
fi

# Avoid running more than one at a time
flock -n /run/lock/ntpdate /usr/sbin/ntpdate-debian -s $OPTS 2>/dev/null || :

) &