Facts and built-in variables
Before requesting a catalog for a managed node, or
compiling one with
puppet apply, Puppet collects system information, called facts, by using the Facter tool. The
facts are assigned as values to variables that you can use anywhere in your manifests. Puppet also sets some additional special variables, called
built-in variables, which behave a lot like facts.
facter -pon the command line, or browse facts on node detail pages in the Puppet Enterprise console. You can also use the PuppetDB API to explore or build tools to search and report on your infrastructure's facts.
Puppet honors fact values of of any data type. It does not convert Boolean, numeric, or structured facts to strings.