gistfile1.rb

require 'facter/lsb'
f = File.open('/tmp/file', 'a')

Facter.add(:operatingsystem) do
  confine :kernel => :sunos
  setcode do "Solaris" end
end

Facter.add(:operatingsystem) do
  confine :kernel => :linux
  setcode do
    f.puts "#{Time.now.inspect} - matched linux"
    if Facter.value(:lsbdistid) == "Ubuntu"
       "Ubuntu"
    elsif FileTest.exists?("/etc/debian_version")
      "Debian"
    elsif FileTest.exists?("/etc/gentoo-release")
      "Gentoo"
    elsif FileTest.exists?("/etc/fedora-release")
      "Fedora"
    elsif FileTest.exists?("/etc/mandriva-release")
      "Mandriva"
    elsif FileTest.exists?("/etc/mandrake-release")
      "Mandrake"
    elsif FileTest.exists?("/etc/meego-release")
      "MeeGo"
    elsif FileTest.exists?("/etc/arch-release")
      "Archlinux"
    elsif FileTest.exists?("/etc/oracle-release")
      "OracleLinux"
    elsif FileTest.exists?("/etc/enterprise-release")
      if FileTest.exists?("/etc/ovs-release")
        "OVS"
      else
        "OEL"
      end
    elsif FileTest.exists?("/etc/arch-release")
      "Arch"
    elsif FileTest.exists?("/etc/vmware-release")
      "VMWareESX"
    elsif FileTest.exists?("/etc/redhat-release")
      txt = File.read("/etc/redhat-release")
      if txt =~ /centos/i
        "CentOS"
      elsif txt =~ /CERN/
        "SLC"
      elsif txt =~ /scientific/i
        "Scientific"
      elsif txt =~ /^cloudlinux/i
        "CloudLinux"
      elsif txt =~ /^Parallels Server Bare Metal/i
        "PSBM"
      elsif txt =~ /Ascendos/i
        "Ascendos"
      else
        "RedHat"
      end
    elsif FileTest.exists?("/etc/SuSE-release")
      txt = File.read("/etc/SuSE-release")
      if txt =~ /^SUSE LINUX Enterprise Server/i
        "SLES"
      elsif txt =~ /^SUSE LINUX Enterprise Desktop/i
        "SLED"
      elsif txt =~ /^openSUSE/i
        "OpenSuSE"
      else
        "SuSE"
      end
    elsif FileTest.exists?("/etc/bluewhite64-version")
      "Bluewhite64"
    elsif FileTest.exists?("/etc/slamd64-version")
      "Slamd64"
    elsif FileTest.exists?("/etc/slackware-version")
      "Slackware"
    elsif FileTest.exists?("/etc/alpine-release")
      "Alpine"
    elsif Facter.value(:lsbdistdescription) =~ /Amazon Linux/
      "Amazon"
    end
  end
end

Facter.add(:operatingsystem) do
  confine :kernel => "VMkernel"
  setcode do
    f.puts "#{Time.now.inspect} - matched VMkernel"
    "ESXi"
  end
end

Facter.add(:operatingsystem) do
  # Default to just returning the kernel as the operating system
  setcode do 
    f.puts "#{Time.now.inspect} - matched default"
    Facter[:kernel].value
  end
end

f.puts "Value of operatingsystem #{Facter.value('operatingsystem')}"