I believe the JSON I had to create to make the  json \'{\"id\": \"#{user}\", \"#{user}\": \"#{password}\"} where the key for the password value is the user.  This works for rabbit and if you look at passwords#secret:
::Chef::EncryptedDataBagItem.load(bag_name, index, secret)[index]
What is passed in from get_password is index={#user}