Make Puppet update my Ubuntuservers and exclude specific packages

I am trying to make Pupet/foreman upate my ubuntu instances and are using this module to update my servers but for an example one of the servers are running Owncloud and i would like to update Owncloud manually! do any of you redit gurus know how to implement this in the manifest?

or is there a "smarter" way?

class ubuntu::upgrade {

Exec { path => [ '/usr/local/sbin', '/usr/local/bin', '/usr/sbin', '/usr/bin', '/sbin', '/bin' ]} exec { 'ubuntu::upgrade': command => 'apt-get upgrade -y', environment => ['DEBIAN_FRONTEND=noninteractive'], require => [Class[ubuntu::update]] } 

}