gistfile1.pp

define limits::limit ($user,$type,$item,$value,$file='/etc/security/limits.conf'){

        $key = "$user/$type/$item"
        $path_list = "domain[.=\"$user\"][type=\"$type\" and item=\"$item\"]"
        $path_exact = "domain[.=\"$user\"][type=\"$type\" and item=\"$item\" and value=\"$value\"]"

        augeas { "limits_conf/${key}/":
                lens    => 'Limits.lns',
                incl    => $file,
                onlyif  => "match $path_exact size==0",
                changes => [
                        "rm $path_list",
                        "set domain[last()+1] $user",
                        "set domain[last()]/type $type",
                        "set domain[last()]/item $item",
                        "set domain[last()]/value $value",
                ],
        }
}