BTW i got it working the search function, indeed it only works from the finder search bar, but.....you can do like spotlight, I tested a particular string from a document that i knew it was unique and the result came.
The mdutil output this when trying to enable spotlight
Code
sudo mdutil -i on /Volumes/jessie-share/
Password:
/Volumes/jessie-share:
Error: unable to perform operation. (-403)
Server search enabled.
This testing was done using a debian jessie VM with GNOME desktop installed. So I haven't tested what would happen if i install tracker from apt, i don't want gnome desktop installed in my headless server.