Hotplug was right under my eyes... Thanks for helping me as it does the job. My problem now is with mounts as minidlna seems to start before the MicroSD card is mounted. I'm looking for the right trigger for this one now.

Is there any simple way to run a script any time wifi is up and running?
Currently, I'm trying to use my Omega2 as a portable DLNA server (in order to serve content in my car to a set of tablets). But, minidlna starts before the network is ready and complains about the lack of network interface. I have to restart the service in order to solve this situation.
I'd like to add this restart command right after the wifi connection is up (no matter what wifi is up, be it the wan connection (192.168.3.1) or the LAN (on my router or whatever).

HotPlug could have been a way to solve this, but it is not available in the repo...