Question

Where does one list the environment variable dependencies for a Rails application?

I don’t want the app to run if the user hasn’t specified the variables or at a minimum output some form of notice that says ***Don’t run until you’ve set the following environment variables…”

Answer 1

I’d put something like that in config/boot.rb:

# usual boot.rb stuff...
raise 'Set PANCAKES in your environment!' unless ENV.has_key? 'PANCAKES'

The nice thing about boot.rb is that it is run very early in the start up process so you don’t have to wait for all the Rails machinery to start (which can take a long time) before you know there’s a problem.