[yocto] Getting a recipe's files from within an image recipe

[colin.helliwell at ln-systems.com]

I have an app which has a config file, and I'd like my two images
(production and dev) to have different configs. Obviously it'd be neater to
keep the two config files within the recipe's directory structure.
I guess I can't do this in the app's recipe since it has no concept of what
image it might end up in. So I could have the the app's recipe deploy one of
the configs by default, and use a step in the 'other' image recipe to
overwrite it.
But is there a way to tell the image recipe where the app's workdir/srcdir
is? Something like ${WORKDIR}_MyRecipe
Or am I just going to have to hard-code the path in?