class common::monitor {
        if $nrpe_mailq_warn { $mailq_warn = $nrpe_mailq_warn } else { $mailq_warn = "5" }
        if $nrpe_mailq_crit { $mailq_crit = $nrpe_mailq_crit } else { $mailq_crit = "10" }

        include nagios::client

        nagios::nrpe_command{
                "check_mailq":
                        command => "check_mailq",
                        parameters => "-M exim -w ${mailq_warn} -c ${mailq_crit}"
        }
}

node "foo" {
   $nrpe_mailq_warn = 50
   $nrpe_mailq_crit = 100

   include common::monitor
}