add smartd fact

Fact for the path to the smartd executable.

lib/facter/smartd.rb

@@ -0,0 +1,7 @@
+Facter.add(:smartd) do
+  confine :kernel => :linux
+
+  setcode do
+    Facter::Util::Resolution.which('smartd')
+  end
+end

spec/unit/facts/smartd_spec.rb

@@ -0,0 +1,25 @@
+require 'spec_helper'
+
+describe 'smartd', :type => :fact do
+  before(:each) { Facter.clear }
+
+  context 'on linux' do
+    context 'not in path' do
+      it do
+        Facter.fact(:kernel).stubs(:value).returns('Linux') 
+        Facter::Util::Resolution.stubs(:which).with('smartd').returns(nil)
+        Facter.fact(:smartd).value.should be_nil
+      end
+    end
+
+    context 'in path' do
+      it do
+        Facter.fact(:kernel).stubs(:value).returns('Linux') 
+        Facter::Util::Resolution.stubs(:which).with('smartd').returns('/usr/sbin/smartd')
+        Facter.fact(:smartd).value.should == '/usr/sbin/smartd'
+      end
+    end
+  end
+
+end
+