The exists? method retrieves the ensure state of the resource. A Boolean is returned, as shown in the following code:

Puppet::Type.type(:mynewtype).provide(:yum) do
   ...
   confine :osfamily =>  :redhat
   defaultfor: osfamily => :redhat
   ...
   def exists?
     begin
       rpm('-q', resource[:name])
     rescue Puppet::ExecutionFailure => e

       false
     end
   end
   ...
 end