Testing has shown that an environment var there isn't working well. Reason is that the call -> ifup -> hook isn't transferring environment.
But checking for alternatives made this even better. ifup makes all options in e/n/i or ifup -o available (prepended with IF_ and uppercased) to called scripts. That way one can not only disable per call, but also per device in e/n/i. So the behavior will be like: 1. default it is running on ifup (old default) 2. one can set a global disable in the config file 3. one disable per device in the devices e/n/i stanza via disable_ntpdate 1 4. one can disable it per call via -o option setting -o disable_ntpdate=1 The following patch reflects that improvement Christian Ehrhardt Software Engineer, Ubuntu Server Canonical Ltd
commit 79f5e2bd41f8d23269364c93cf4dad97957b759f Author: Christian Ehrhardt <[email protected]> Date: Mon Jul 4 14:30:26 2016 +0200 d/ntpdate-debian allow disabling the call to ntpdate Done via setting in /etc/default/ntpdate and environment variable (LP: #1206164). So the behavior will be like: 1. default it is running on ifup (old default) 2. one can set a global disable in the config file 3. one disable per device in the devices e/n/i stanza via "disable_ntpdate 1" 4. one can disable it per call via -o option setting -o disable_ntpdate=1 diff --git a/debian/ntpdate-debian b/debian/ntpdate-debian index 4f5b17b..f4be2c4 100644 --- a/debian/ntpdate-debian +++ b/debian/ntpdate-debian @@ -6,6 +6,8 @@ if [ -r /etc/default/ntpdate ]; then . /etc/default/ntpdate fi +[ "${IF_DISABLE_NTPDATE:-0}" != "0" -o "${NTPDATE_IFUP_DISABLE}" != "0" ] && exit 0 + if [ "$NTPDATE_USE_NTP_CONF" = yes ]; then for f in /etc/ntp.conf /etc/openntpd/ntpd.conf; do if [ -r "$f" ]; then diff --git a/debian/ntpdate.default b/debian/ntpdate.default index f239b18..8d98440 100644 --- a/debian/ntpdate.default +++ b/debian/ntpdate.default @@ -5,6 +5,13 @@ # so you only have to keep it in one place. NTPDATE_USE_NTP_CONF=yes +# Set to 1 to disable the automated ntpdate-debian call triggered on ifup +# For more fine granular control this can also be disabled per device by +# adding "disable_ntpdate 1" to its stanza in /etc/network/interfaces. +# Furthermore it can be disabled per ifup call with by adding +# "-o disable_ntpdate=1" to it. +NTPDATE_IFUP_DISABLE="0" + # List of NTP servers to use (Separate multiple servers with spaces.) # Not used if NTPDATE_USE_NTP_CONF is yes. NTPSERVERS="ntp.ubuntu.com"

