Include the default zones on RedHat

RedHat's default zones are baked into the stock named.conf, which the module's
template completely rewrites. Since the module is extremely view-based, and the
Debian default-zones are repositioned into the zones, let's take those defaults
out of the stock named.conf, build a configuration file out of them and include
it in the view just the same.

manifests/defaults.pp

@@ -13,6 +13,8 @@ class bind::defaults (
     $nsupdate_package       = undef,
     $managed_keys_directory = undef,
     $default_zones_warning  = undef,
+    $default_zones_include  = undef,
+    $default_zones_source   = undef,
 ) {
     unless is_bool($supported) {
         fail('Please ensure that the dependencies of the bind module are installed and working correctly')

manifests/init.pp

@@ -62,6 +62,12 @@ class bind (
         content => template('bind/named.conf.erb'),
     }
 
+    if $default_zones_source {
+        file { $default_zones_include:
+            source => $default_zones_source,
+        }
+    }
+
     class { 'bind::keydir':
         keydir => "${confdir}/keys",
     }

manifests/view.pp

@@ -12,6 +12,7 @@ define bind::view (
     $order                        = '10',
 ) {
     $confdir = $::bind::confdir
+    $default_zones_include = $::bind::default_zones_include
 
     concat::fragment { "bind-view-${name}":
         order   => $order,