Am 2017-09-23 um 13:08 schrieb Ritesh Raj Sarraf: > Hello Jakobus, > > On Thu, 2017-09-07 at 21:06 +0200, Jakobus Schürz wrote: >>> >>> I am currently testing with the changes you've mentioned (And would >>> like to move to a socket based setup). >> >> For sure :-) >> >> Here are all my units for leafnode: >> > > Thank you very much. With your setup in place, I have been able to > successfully run leafnode with systemd integration. I tested it for > around a week now and everything is working perfect. > > If I could add a wishlist, it is dependency of the fetchnews service > unit/timer to runtime depend on network-online.target. > > As I understand it now, fetchnews will be triggered only if the > network-online.target is active. So it does solve the service startup > at boot time, ensuring that fetchnews does not get triggered until and > unless a working operational network setup is in place. > > But like yours', my leafnode setup is on my laptop. Which goes through > multiple suspend/resume and network cycles. There are also times, when > upon resume there is no network (networkless location, airplane mode > etc). Under such scenarios, systemd should only invoke such timers if > an active network connection is available. > > Do you happen to know if we could configure the units/timers in such a > way that it probes the network-online.target for actual network > connectivity, and only then invoke the timers ?
This is a good point. I also asked on the systemd list for this (not only leafnode should be only started, only when a network-connection is available... fetchmail is the same). They said me, systemd starts services and can restart a service, if it stops working in case of a failure. But systemd is not designed to watch available network-connections... So network-online.target ist started, when for example network-manager.service ist started successfully... not when the connection is up and running. Network-Manager has to start and stop a special target, when connection-state is changing. But that is not as easy as I thougt... How to check, if a connection is up? How to check, if a connection is working? Ping some servers? Ping a special server? What is, if a server is configured, not to answer ICMP? I'm also working on a solution to use an own target, which i call "connection-online.target" and "[email protected]" to instantiate this target for every network-device. The instantiated targets ([email protected], [email protected] or for tun0...) have the option, to start a service only if a certain device is online. Bind a service to "connection-online.target", it will start if any connection is online. The dependecy for fetchnews.timer can be "connection-online.target". Connection-online.target gets started from a network-manager-dispatcher script, and also gets stopped on such a script. The dependencies for fetchnews.timer are "PartOf=connection-online.target After=connection-online.target" So every time, connection-online.target is started, fetchnews.timer is also startet. The same for stopping connection-online.target. You need a dispatcher-script which checks the online-state with "nm-online", and depending on the result, connection-online.target is started or stopped... But what, if some doesn't use NetworkManager? If someone is using wicd or systemd-networkd? Ok, for the last, there could be a native solution... but I do not use systemd-networkd, because it is not practicable on Laptops... For wicd, there is also a possibility for starting scripts on statechanges... so connection-online should also be working. But I haven't finnished this solution. For now, the dependecy to network-online.target should be enough. Best regards Jakob
signature.asc
Description: OpenPGP digital signature
