Added server_id fact

use mac address for "guaranteed" uniqueness ;)

lib/facter/server_id.rb

@@ -0,0 +1,9 @@
+def get_mysql_id
+  Facter.value(:macaddress).split(':').inject(0) { |total,value| (total << 4) + value.hex }
+end
+
+Facter.add("mysql_server_id") do
+  setcode do
+    get_mysql_id
+  end
+end