GCE default NTP configuration uses both leap-smeared and true UTC sources
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
cloud-images |
Fix Committed
|
Low
|
Unassigned | ||
ntp (Ubuntu) |
Won't Fix
|
Low
|
Unassigned |
Bug Description
A default install of cloud images on GCE results in a configuration of NTP which will likely be problematic during leap seconds, because it uses both Google's leap-smeared time source, and the public pool, which uses true UTC. These should not be combined in the default configuration.
The principle of least astonishment would suggest that a non-standard feature like leap smearing should be disabled by default.
This behaviour has been consistent in the 3 different GCE regions in which I've recently created instances.
root@instance-4:~# cat /etc/cloud/
build_name: server
serial: 20161221
root@instance-4:~# cat /etc/ntp.conf
# /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help
driftfile /var/lib/
# Enable this if you want statistics to be logged.
#statsdir /var/log/ntpstats/
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable
# Specify one or more NTP #servers.
# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
# on 2011-02-08 (LP: #104525). See http://
# more information.
pool 0.ubuntu.
pool 1.ubuntu.
pool 2.ubuntu.
pool 3.ubuntu.
# Use Ubuntu's ntp #server as a fallback.
pool ntp.ubuntu.com
# ... comments snipped ...
# By default, exchange time with everybody, but don't allow configuration.
restrict -4 default kod notrap nomodify nopeer noquery limited
restrict -6 default kod notrap nomodify nopeer noquery limited
# Local users may interrogate the ntp #server more closely.
restrict 127.0.0.1
restrict ::1
# Needed for adding pool entries
restrict source notrap nomodify noquery
# ... comments snipped ...
# Google NTP source. This was added as part of the gce-cloud-config package.
server metadata.
I've tried to tag this as also affecting gce-cloud-config (source package gce-utils), but launchpad seems unable to find it.