sort add_header values for vhost

spec/defines/resource_vhost_spec.rb

@@ -847,6 +847,21 @@ describe 'nginx::resource::vhost' do
 
         it { is_expected.to contain_concat('/etc/nginx/sites-available/www_rspec-vhost_com.conf') }
       end
+
+      context 'when add_hedar is set' do
+        let :params do default_params.merge({
+          :add_header => { 'header3' => 'test value 3', 'header2' => 'test value 2', 'header1' => 'test value 1' }
+        }) end
+
+        it 'should have correctly ordered entries in the config' do
+          is_expected.to contain_concat__fragment("#{title}-header").with_content(/
+            %r|
+            \s+add_header\s+header1 test value 1;\n
+            \s+add_header\s+header2 test value 2;\n
+            \s+add_header\s+header3 test value 3;\n
+            |/)
+        end
+      end
     end
   end
 end

templates/vhost/vhost_header.erb

@@ -70,8 +70,8 @@ server {
   resolver                  <% Array(@resolver).each do |r| %> <%= r %><% end %>;
 <% end -%>
 <% if @add_header -%>
-  <%- @add_header.each do |key,value| -%>
-  add_header              <%= key %> <%= value %>;
+  <%- @add_header.keys.sort.each do |key| -%>
+  add_header              <%= key %> <%= @add_header[key] %>;
   <%- end -%>
 <% end -%>
 <% if @rewrite_to_https -%>