[systemd-devel] Unit to test if a domain is reachable

[Colin Guthrie]

'Twas brillig, and Moviuro at 17/07/14 11:41 did gyre and gimble:
> On Thursday 17 July 2014 12:12:22 you wrote:
>> Why not just use network-online.target?
>> http://www.freedesktop.org/software/systemd/man/systemd.special.html#network
>> -online.target
> o If it succeeds, the unit that needs to reach %i gets launched and my 
> reachable-retry@ *does not* enter SUCCESS or whatever "good" state you can 
> think of: it just stays asleep until someone else wants to recheck later if 
> the domain is still reachable (e.g. domain goes down, my ISP goes crazy, I 
> suspend my computer...).
> 
> network-online.target does not fulfill these requirements. It stays in 
> "SUCCESS" across suspend/resume cycles. Therefore, it is *not* a correct 
> indicator.

I don't think any kind of unit is the right approach here. You need
something "active" that listens to events from devices and determines
the best course of action thereafter.

I think anything you glue together with systemd units here will be a bit
of a hack, but perhaps others will disagree.

Col

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Colin Guthrie
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