1 files changed, 38 insertions, 0 deletions
diff --git a/lib/gitlab/database/loose_foreign_keys.rb b/lib/gitlab/database/loose_foreign_keys.rb
new file mode 100644
index 00000000000..1ecfb5ce47f
--- /dev/null
+++ b/lib/gitlab/database/loose_foreign_keys.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    module LooseForeignKeys
+      def self.definitions_by_table
+        @definitions_by_table ||= definitions.group_by(&:to_table).with_indifferent_access.freeze
+      end
+
+      def self.definitions
+        @definitions ||= loose_foreign_keys_yaml.flat_map do |child_table_name, configs|
+          configs.map { |config| build_definition(child_table_name, config) }
+        end.freeze
+      end
+
+      def self.build_definition(child_table_name, config)
+        parent_table_name = config.fetch('table')
+
+        ActiveRecord::ConnectionAdapters::ForeignKeyDefinition.new(
+          child_table_name,
+          parent_table_name,
+          {
+            column: config.fetch('column'),
+            on_delete: config.fetch('on_delete').to_sym,
+            gitlab_schema: GitlabSchema.table_schema(child_table_name)
+          }
+        )
+      end
+
+      def self.loose_foreign_keys_yaml
+        @loose_foreign_keys_yaml ||= YAML.load_file(Rails.root.join('lib/gitlab/database/gitlab_loose_foreign_keys.yml'))
+      end
+
+      private_class_method :build_definition
+      private_class_method :loose_foreign_keys_yaml
+    end
+  end
+end