Added SRU Template. ** Description changed:
+ [Impact] + + * Fixes several broken cases, those are: + * Case 1 - ntp configured to drift time slowly, but time jumping + - ntp is running and drifts time towards a target being way off + - an interface comes up + - stop ntpd + - warp time via ntpdate-debian (static interfaces will even set -b) + - (re-)start ntpd + - if users relied on non-time warp they are now in trouble + + * Case 2 - ntp start/stop storms + - ntpd comes up normally + - the admin brings interfaces up/down rather often + - ntp is restarted very very often due to this for no reason + => reason for bugs like debian 823533 + + * Case 3 - unintentional enablement of ntp + - ntpd is installed but disabled (for whatever reason) + - all is fine on any ifup/down + - one installs ntpdate, maybe even without realizing due to a depends + - now on the next ifup ntpd (or openntpd) will be started + + * Solution, drop the broken Delta + + [Test Case] + + * Testing Case 2/3 as it is the easiest, case 1 needs a more complex + setup to cause the time drift but otherwise works the same way. + - install ntp and ntpdate + - stop ntp + - ifup/ifdown an interface multiple times; as simplification you can + also call /etc/network/if-up.d/ntpdate directly (not that this + spawns the change asnchronous and locks concurrency, so do that a + few times over the time of a minute or so) + - the service of ntp should still be stopped and not report plenty of + restarts + + + [Regression Potential] + + * It improves a lot of cases (otherwise we wouldn't SRU), but there is + one regression potential I can see: + + - users that relied on starting NTP later on after other interfaces + got up due to that code in ntpdate which did that as a side effect. + But that is outweigh by Case2/3 for the majority of users. And even + Case1 only hits this potential regression on e.g. late network + intialization, but in that case please remind that the default + (systemd timedatectl) would handle that. + + - Since most users of ntp do not install ntpdate (which doesn't work + when ntp is active) we should be rather safe to assume that almost + no one should rely on that side effect. + + - Furthermore this is a Ubuntu Delta for very long, cause issues (see + the references on the git commit) but never made it into Debian - + in that sense another indicator it isn't an important delta to + have. + + [Other Info] + + * The original intention "what if net is available too late" fixed + correctly would not be part of ntpdate, but ntp and additionally + check if it is actually meant to be enabled - but I never seen/heard + of any of it since systemd is around - maybe new ordering mostly + avoids the original issue. + + + --- + + I've installed ntp service on the clean ubuntu 16.04 server system. Configured it. Checked that it works, but, after reboot, it doesn't start automatically. When I check: 'systemctl is-enabled ntp', it shows enabled. If I manually start it 'systemctl start ntp' it starts just fine and woks correctly, but until I manually start it, 'systemctl status ntp' shows: Loaded: loaded (/etc/init.d/ntp; bad; vendor preset: enabled) Active: inactive (deadi) Installed 1.29ubuntu2 version of init-systems-helper, but it didn't fix the problem. Found a bugreport on ntpd package: https://bugs.launchpad.net/ubuntu/+source/ntp/+bug/1577596 led to solution that involves a change to be made in file: /etc/network/if-up.d/ntpdate of ntpdate package After changing from: ______________CODE_START______________ invoke-rc.d --quiet $service stop >/dev/null 2>&1 || true # Avoid running more than one at a time flock -n /run/lock/ntpdate /usr/sbin/ntpdate-debian -s $OPTS 2>/dev/null || : invoke-rc.d --quiet $service start >/dev/null 2>&1 || true ______________CODE_END______________ to: ______________CODE_START______________ systemctl --quiet stop $service.service >/dev/null 2>&1 || true # Avoid running more than one at a time flock -n /run/lock/ntpdate /usr/sbin/ntpdate-debian -s $OPTS 2>/dev/null || : systemctl --quiet start $service.service >/dev/null 2>&1 || true ______________CODE_END______________ ntpd service started launching on boot. System Information: lsb_release -rd: Description: Ubuntu 16.04 LTS Release: 16.04 apt-cache policy ntpdate: ntpdate: Установлен: 1:4.2.8p4+dfsg-3ubuntu5 Кандидат: 1:4.2.8p4+dfsg-3ubuntu5 Таблица версий: *** 1:4.2.8p4+dfsg-3ubuntu5 500 500 http://ru.archive.ubuntu.com/ubuntu xenial/main amd64 Packages 100 /var/lib/dpkg/status -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1593907 Title: ntpdate startup routine prevents ntp service from launching up on Ubuntu 16.04 server on system boot; manually starting ntp service works: [FIX in DESCRIPTION], just need to apply it and release a new version To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ntp/+bug/1593907/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
