gistfile1.rb

Usergroup.all.each do |usergroup|
  external = ExternalUsergroup.new(:auth_source_id => AuthSource.find_by_name('CERN').id, 
                                   :name           => usergroup.name,
                                   :usergroup_id   => usergroup.id)
  if external.save
    puts "Usergroup #{usergroup.name} associated with external usergroup #{external.name}"
  else
    puts "Usergroup #{usergroup.name} could not be associated with external usergroup #{external.name}"
    puts "  -- #{external.errors}"
  end
end