[CentOS] Systemd service unit file needs to wait until a specific interface is up

Thu Sep 24 14:06:14 UTC 2020
centos at niob.at <centos at niob.at>

On 24/09/2020 13:41, Simon Matter wrote:
>>> I've been dealing with issues like this for a while - systems with
>>> multiple interfaces, some of which do not come up for quite a while, and
>>> I need to wait for all to be up before running certain tasks.  Still
>>> haven't found anything very satisfactory.
>> All good points. Thank you for that douse of reality.
> I'm just wondering, is there a chance to make this work reliable without
> modifying the source code of systemd?
> Simon
Polling? If "some of [them] do not come up for quite a while" it would 
not be a problem to add another couple of seconds, I guess.

It might be against an "event driven" aproach, but it would work and you 
can add all sorts of tests to make sure everything is ready for your job 
(eg. including reachability of remote services, etc.)