[yocto] Recipes that update a shared file

[seth bollinger]

Hello All,

What's the best practice for recipes that need to update a shared file 
provided by a different recipe?  For example let's say that the 
widget-watcher recipe creates /etc/ww.conf and the widget1, and widget2 
recipes need to append a line to the config.  I've searched through the 
recipes a bit and can't find a good example.  The closest that I've seen 
is pkg_postinst().  Is that the best method?

Thanks!

Seth