On Mon, 27.06.16 10:34, Kai Hendry (hen...@webconverger.com) wrote: > Hi there, > > I had a quick look at > https://github.com/systemd/systemd/tree/master/src/timesync to try work > out if /usr/lib/systemd/systemd-timesyncd had some sort of fallback if > ntp UDP port 123 traffic is blocked. > > This happens all too often with my deployments of Webconverger and I was > wondering if asking for HTTP based time synchronization was a sane thing > to ask for from systemd. > > An example implementation can be found here: > https://github.com/ccrisan/motioneyeos/blob/master/board/common/overlay/etc/init.d/S50date#L31
I figure having something like this makes some sense. There was a plan to add something like an http-based ping scheme to networkd, so that networkd can do captive portal detection natively, and at the same time acquire some useful data from the ping server, for example a suggested default timezone/language/location and so on, via some http request or so. NetworkManager, Firefox, and so on all implement that on their own these days, to limit degrees, and even ConnMan has been doing this for quite some time. It's a bit of a privacy issue, as when this is enabled there's an instant ping to some central server attempted, but I still think for many setups having this makes a ton of sense. I figure using this as also as crappy fallback if NTP doesn't work and hasn't worked in a while definitely makes sense. I am not convinced however to reuse some HTTP server for this that isn't actually explicitly set up for this scheme, and thus is known to provide correct times. For example, making clients sync their clocks to www.google.com appears a questionnable idea to me. So yeah, I like the idea, but doing this properly is not trivial I figure, in particular if we want to take the privacy issue into account and provide a at least a bit of anonymity for clients. Lennart -- Lennart Poettering, Red Hat _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel