Augeas is one of those little know but hugely powerful tools in the configuration management world. It allows a unified configuration language to view files in different formats. It does so with different lens’. The lens files are really useful when you use augeas as a library to parse and edit files.

Versions tested
Software Version OS
puppet 6.21.0 Ubuntu

I recently needed to demo how to use augeas with facter. This needs to be optimised to not just be Augeas::NONE but it allows you to have augeas parse the file rather then ruby . This is useful in cutting down the code needed and also the development needed over time. Its also likely to handle corner cases better then just reading a file in line by line.

Facter.add(:default_realm) do
  setcode do
      require 'augeas'
      aug = Augeas::open('/', nil, Augeas::NONE)
      default_realm = aug.get('/files/etc/krb5.conf/libdefaults/default_realm')
    rescue Exception
      Facter.debug('ruby-augeas not available')