DKMS is handled by a separate module.

Modulefile

 name    'nono-zfs'
-version '0.0.1'
+version '0.0.2'
 source 'git://forge-git.ircam.fr/puppet-module-base-zfs.git'
 author 'nono'
 license 'GPLv3'
@@ -7,5 +7,4 @@ summary 'ZFS Puppet module'
 description 'This module installs ZFS from http://zfsonlinux.org/ on Linux hosts. It does not manage pools, just the kernel-level support.'
 project_page 'http://forge.ircam.fr/p/puppet-module-base-zfs/'
 
-## Add dependencies, if any:
-# dependency 'username/name', '>= 1.2.0'
+dependency 'nono/dkms', '>= 0.0.1'

manifests/init.pp

@@ -25,15 +25,9 @@
 #
 class zfs {
 
-  if $::operatingsystem in ['RedHat', 'CentOS', 'Scientific'] {
+  include dkms
 
-    # We need kernel-headers for DKMS.
-    if !defined(Package['kernel-devel']) {
-      package { 'kernel-devel':
-        ensure => present,
-        before => Package['zfs'],
-      }
-    }
+  if $::operatingsystem in ['RedHat', 'CentOS', 'Scientific'] {
 
     package { 'zfs-release':
       ensure   => present,