application.rb

module MyApp
  class Application < Rails::Application
    # Allows us to read configuration from unconventional places
    # (e.g. /etc).
    #
    # To use:
    #   config/config_paths.yml:
    #     development:
    #       config/blah: config/blah.yml
    #
    #   config/initializers/blah.rb:
    #     BLAH_CONFIG = YAML.load_file(Rails.application.paths['config/blah'].first)
    #
    def paths
      return @paths if @paths

      @paths = super
      config_paths = YAML.load_file("#{config.root}/config/config_paths.yml") rescue {}
      if config_paths[Rails.env] then
        config_paths[Rails.env].each do |key, path|
          @paths.add key, :with => path
        end
      end
      return @paths
    end
  end
end

config_paths.yaml

development:
  config/blah: config/blah.yml

production:
  config/blah: /etc/myapp/blah.yml
  config/database: /etc/myapp/database.yml