diff --git a/lib/gitlab/ci/config/node/configurable.rb b/lib/gitlab/ci/config/node/configurable.rb
new file mode 100644
index 00000000000..9c04a1cdc08
--- /dev/null
+++ b/lib/gitlab/ci/config/node/configurable.rb
@@ -0,0 +1,39 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        module Configurable
+          extend ActiveSupport::Concern
+
+          def keys
+            self.class.nodes || {}
+          end
+
+          private
+
+          def add_node(key, entry_class)
+            if @value.has_key?(key)
+              entry = entry_class.new(@value[key], @root, self)
+            else
+              entry = Node::Null.new(nil, @root, self)
+            end
+
+            @nodes[key] = entry
+          end
+
+          class_methods do
+            attr_reader :nodes
+
+            private
+
+            def add_node(symbol, entry_class)
+              node = { symbol.to_sym => entry_class }
+
+              (@nodes ||= {}).merge!(node)
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/config/node/entry.rb b/lib/gitlab/ci/config/node/entry.rb
index 302cded664f..c45744efdf5 100644
--- a/lib/gitlab/ci/config/node/entry.rb
+++ b/lib/gitlab/ci/config/node/entry.rb
@@ -20,8 +20,8 @@ module Gitlab
           def process!
             return if leaf? || invalid?
 
-            keys.each do |key, entry_class|
-              add_node(key, entry_class)
+            keys.each do |key, entry|
+              add_node(key, entry)
             end
 
             nodes.each(&:process!)
@@ -49,7 +49,7 @@ module Gitlab
           end
 
           def keys
-            self.class.nodes || {}
+            {}
           end
 
           def errors
@@ -60,7 +60,11 @@ module Gitlab
             super unless keys.has_key?(name)
             raise InvalidError unless valid?
 
-            @nodes[name].value
+            @nodes[name].try(:value)
+          end
+
+          def add_node(key, entry)
+            raise NotImplementedError
           end
 
           def value
@@ -74,28 +78,6 @@ module Gitlab
           def description
             raise NotImplementedError
           end
-
-          private
-
-          def add_node(key, entry_class)
-            if @value.has_key?(key)
-              entry = entry_class.new(@value[key], @root, self)
-            else
-              entry = Node::Null.new(nil, @root, self)
-            end
-
-            @nodes[key] = entry
-          end
-
-          class << self
-            attr_reader :nodes
-
-            private
-
-            def add_node(symbol, entry_class)
-              (@nodes ||= {}).merge!(symbol.to_sym => entry_class)
-            end
-          end
         end
       end
     end
diff --git a/lib/gitlab/ci/config/node/global.rb b/lib/gitlab/ci/config/node/global.rb
index 2e899b0b2a3..5a176ab5eaf 100644
--- a/lib/gitlab/ci/config/node/global.rb
+++ b/lib/gitlab/ci/config/node/global.rb
@@ -3,6 +3,8 @@ module Gitlab
     class Config
       module Node
         class Global < Entry
+          include Configurable
+
           add_node :before_script, Script
         end
       end