1 files changed, 38 insertions, 0 deletions
diff --git a/lib/gitlab/config/entry/validatable.rb b/lib/gitlab/config/entry/validatable.rb
new file mode 100644
index 00000000000..1c88c68c11c
--- /dev/null
+++ b/lib/gitlab/config/entry/validatable.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Config
+    module Entry
+      module Validatable
+        extend ActiveSupport::Concern
+
+        def self.included(node)
+          node.aspects.append -> do
+            @validator = self.class.validator.new(self)
+            @validator.validate(:new)
+          end
+        end
+
+        def errors
+          @validator.messages + descendants.flat_map(&:errors) # rubocop:disable Gitlab/ModuleWithInstanceVariables
+        end
+
+        class_methods do
+          def validator
+            @validator ||= Class.new(Entry::Validator).tap do |validator|
+              if defined?(@validations)
+                @validations.each { |rules| validator.class_eval(&rules) }
+              end
+            end
+          end
+
+          private
+
+          def validations(&block)
+            (@validations ||= []).append(block)
+          end
+        end
+      end
+    end
+  end
+end