#Used to configure variables for the app per environment (instead of attributes).
#I have since refactored how this works so treat this as example code, aka I
#have not tested this and it is not complete.
#FWIW using libraries in the cookbook to set these variables
#for smaller apps I would keep this in the attributes

app_name = 'yourname'
default = {
  name: app_name
  gemset: app_name
  ruby_ver: 'ruby-1.8.7-p352',
  deploy_user: 'deployer',
  environment: node[:environment],
  #...
}

staging = {
  app_root: '/export/staging/yourname',
  #...
}

case node[:environment]
when "staging"
  rails_attributes = Chef::Mixin::DeepMerge.merge(default, staging)
end

# Don't know why I saved this in a seperate hash before the deep merge...
original_node_attributes = node.default.to_hash
node.default[:rails] = Chef::Mixin::DeepMerge.merge(rails_attributes, original_node_attributes["rails"])