Puppet and OS detection

As you may know, Puppet uses “facter” to get facts about the machine it is about to configure. That’s fine, and a nice concept. One can later use variables in a puppet manifest to do different things depending on what facter tells. For example, the operating system name … oh no! This thing is really stupid … Here’s the code one has to do to be compatible with puppet from version 3 up to 5:

if $::lsbdistcodename == undef{
# This works around differences between facter versions
if $facts['os']['lsb'] != undef{
$distro_codename = $facts['os']['lsb']['distcodename']
$distro_codename = $facts['os']['distro']['codename']
$distro_codename = downcase($::lsbdistcodename)

Indeed, the global variable $::lsbdistcodename still existed up to Stretch (and is gone in Buster). The global $::facts wasn’t an array before (but a hash), so in Jessie, it breaks with the error message “facts is not a hash or array when accessing it with os”. So, one need the full code above to make this work.

It’s ok to improve things. It is NOT OK to break os detection. To me it is a very bad practice from upstream Puppet authors. I’m publishing this in the hope to avoid others to fall in the same trap as I did.