One final note - this uses PO parser provided by fast_gettext. This is good for development setups when you dont need to compile those into MO files. If you want to use MO binary files for lookups, in production change this line to:

    FastGettext.add_text_domain 'app', :path => locale_dir

and make sure you generate mo files during the build phase (e.g. RPM SPEC file using the rake task). The good practice for Rails application can be to compile MO files into the same folder (./locale/*).

(In katello we also do use slower PO parser in production.)