@smarterclayton, yes they may, but also they may not have the assets precompiled. In openshift 2.0 we use the disable_asset_compilation marker to disable the precompilation. Wasn't sure how to disable the precompilation in a dockerish way, cause we would need to introduce some kind of convention, which we don't want. 
Any tip on that ?

@jwforres yes we can't but if the application is a rails app, in order to precompile the assets the app Gemfile needs to contains a JavaScript runtime (rubyracer, therubyrhino, ...) which will also install execjs as a dependency and so it will be located in the Gemfile.lock. 
Thats why I also check in the `rake_assets_precompile` function that the app is a rails app.
It is similar approach like we use right now in the ruby cartridge.