better code organization?

[Suliman via Digitalmars-d-learn]

I am writing in D server and client apps. Server is base on 
vibed. Server and client have some common code (example working 
with config class). How I can prevent code duplication? I can 
move config code to separate module, but how to link on it?

server
client
modules --??
it it's good? or there is better ways?