A custom Puppet Fact to find local accounts on a Windows Machine. The sid's will be used for HKEY_USERS\${sid}

local_accounts.rb

Facter.add('local_account_sids') do
  confine osfamily: 'Windows'
  setcode do
    # https://stackoverflow.com/questions/29330882/why-cant-i-include-win32-in-my-chef-recipe
    # require 'win32/registry'
    # include ::Win32

    # https://www.lifewire.com/hkey-users-2625903
    # Found someone reference that S-1-5-21 is only local users
    local_user_prefix = 'S-1-5-21-'
    exclude_postfix = '_Classes'
    default_account = '.DEFAULT'

    res = []

    ::Win32::Registry.open(::Win32::Registry::HKEY_USERS, '').each_key do |subkey, wtime|
      if subkey == default_account or
         (subkey.start_with?(local_user_prefix) and !subkey.end_with?(exclude_postfix))
        res << subkey
      end
    end

    res
  end
end