Stricter data type on apache::vhost::filters

This was previously filtered out but it's best if the information simply
never is entered in the first place.

The include is also simplified and only applied if the vhost is present.

Author: ekohl

manifests/vhost.pp

@@ -1855,7 +1855,7 @@
   Optional[Variant[Array[String],String]] $redirectmatch_dest                         = undef,
   Array[String[1]] $headers                                                           = [],
   Array[String[1]] $request_headers                                                   = [],
-  Optional[Array[String]] $filters                                                    = undef,
+  Array[String[1]] $filters                                                           = [],
   Optional[Array] $rewrites                                                           = undef,
   Optional[String] $rewrite_base                                                      = undef,
   Optional[Variant[Array[String],String]] $rewrite_rule                               = undef,
@@ -2259,13 +2259,6 @@
     }
   }
 
-  # Check if mod_filter is required to process $filters
-  if $filters {
-    if ! defined(Class['apache::mod::filter']) {
-      include apache::mod::filter
-    }
-  }
-
   # Check if mod_env is required and not yet loaded.
   # create an expression to simplify the conditional check
   $use_env_mod = $setenv and ! empty($setenv)
@@ -2906,7 +2899,9 @@
 
   # Template uses:
   # - $filters
-  if $filters and ! empty($filters) {
+  if ! empty($filters) and $ensure == 'present' {
+    include apache::mod::filter
+
     concat::fragment { "${name}-filters":
       target  => "${priority_real}${filename}.conf",
       order   => 330,

templates/vhost/_filters.erb

@@ -1,10 +1,8 @@
-<% if @filters and ! @filters.empty? -%>
+<% unless @filters.empty? -%>
 
   ## Filter module rules
   ## as per http://httpd.apache.org/docs/2.2/mod/mod_filter.html
-  <%- Array(@filters).each do |filter| -%>
-    <%- if filter != '' -%>
+  <%- @filters.each do |filter| -%>
   <%= filter %>
-    <%- end -%>
   <%- end -%>
 <% end -%>