Usando o módulo Puppet apt

Sou totalmente iniciante no Puppet e estou tendo um problema ao tentar instalar um pacote por meio do apt-module.

class newrelic {
        apt::source {
                'newrelic':location => 'http://apt.newrelic.com/debian/',
                repos => 'non-free',
                key => '548C16BF',
                key_source => 'https://download.newrelic.com/548C16BF.gpg',
                include_src => false,
                release => 'newrelic',
        }
        package {
                'newrelic-sysmond':ensure => 'present',
                notify => Service['newrelic-sysmond'],
                require => Class['apt::source'],
        }
        service {
                'newrelic-sysmond':ensure => 'running',
                enable => true,
                hasrestart => true,
                hasstatus => true,
                require => Exec['newrelic_config'],
        }
        exec {
                'newrelic_config':path => '/bin:/usr/bin',
                command => "/usr/sbin/nrsysmond-config --set license_key=xxxxxxx",
                user => 'root',
                group => 'root',
                require => Package['newrelic-sysmond'],
                notify => Service['newrelic-sysmond'],
        }
}

Este é o erro que recebo:

Warning: Scope(Class[Apt::Update]): Could not look up qualified variable '::apt::always_apt_update'; class ::apt has not been evaluated
Warning: Scope(Class[Apt::Update]): Could not look up qualified variable 'apt::update_timeout'; class apt has not been evaluated
Warning: Scope(Class[Apt::Update]): Could not look up qualified variable 'apt::update_tries'; class apt has not been evaluated
Notice: Compiled catalog for host.domain.local in environment production in 0.33 seconds
Error: Could not find dependency Class[Apt::Source] for Package[newrelic-sysmond] at /home/jeroen/puppet/modules/newrelic/manifests/init.pp:16

Alguma ideia do que estou fazendo de errado no meu módulo?