cat /etc/puppet/manifests/site.pp
node default {
    include ssh
}

-----------------------------------------------------------------------------------

cat /etc/puppet/modules/ssh/manifests/init.pp
class ssh {
   file { 'authorized_keys':
        path    => '/root/.ssh/authorized_keys',
        source  => "puppet:///modules/ssh/authorized_keys",
      }
}

-----------------------------------------------------------------------------------

ll /etc/puppet/modules/ssh/authorized_keys
-rw-r--r-- 1 root root 3031 Nov  8 15:54 /etc/puppet/modules/ssh/authorized_keys