gistfile1.rb

# File: roles/common.rb
name "common"
description "Applied to all servers"
recipes "users"
default_attributes(
  :groups => {
    :admins => {:gid => 900},
  },
  :users => {
    :kevn => { :password => "*", :comment => "Kevin", :uid => 1001, :group => :admins },
    :bob  => { :password => "*", :comment => "Bob", :uid => 1002, :group => :admins },
    :joe  => { :password => "*", :comment => "Joe", :uid => 1003, :group => :admins },
    :al   => { :password => "*", :comment => "Al", :uid => 1004, :group => :admins },
  },
)

# File: roles/app.rb
name "app"
description "App server"
recipes "merb_site" # Also tried adding "users" here
default_attributes(
  :groups => {
    :app => {:gid => 800},
  },
  :users => {
    :app => { :password => "*", :comment => "App User", :uid => 800, :group => :app }
  }
)

# File: /etc/chef/node.json
{
  "run_list": [ "role[common]", "role[app]" ]
}

# File: site-cookbooks/users/recipes/default.rb
raise [node.groups.keys, node.users.keys].inspect

# Results of the raise in the cookbook: [["app"], ["joe", "bob", "kevn", "al"]]
# But I would expect: [["admins", "app"], ["joe", "bob", "kevn", "al", "app"]]