ntp tweaks

[parazyd]

To save battery, we shouldn't run an ntp daemon all the time. Rather look into setting time once and quitting.

Currently this is solved with ntpsec-ntpdate, which tries to set the time once upon an Internet connection is established.

We might want to look into a daemon that will keep trying until the time is actually set in case ntpsec-ntpdate fails.

[clort81]

Works okay for me as-is.

[petterreinholdtsen]

ntpsec-ntpdate call ntpdate, which fail when either ipv4 or ipv6 addresses behind the dns names given on the command line is unavailable, for example when the unit do not have ipv6 routing. look like https://bugs.debian.org/293793 returned since 2005.

[petterreinholdtsen]

I worked around the broken ntpdate behaviour by patching /usr/sbin/ntpdate-debian, and doing two separate calls, one for IPv4 and one for IPv6. One of them might fail, but the other will most likely work. The new script end like this:

# shellcheck disable=SC2086
/usr/sbin/ntpdate -6 $NTPOPTIONS "$@" $NTPSERVERS
exec /usr/sbin/ntpdate -4 $NTPOPTIONS "$@" $NTPSERVERS

[petterreinholdtsen]

I discovered that the problem only exist with the ntpsec-ntpdate package used by Maemo, while the ntpdate package do not have this problem. Perhaps change the underlying implementation?

The issue with ntpsec-ntpdate is reported to https://bugs.debian.org/971523 .

[sicelo]

chrony is an alternative ntp daemon that promises battery friendliness