1 files changed, 62 insertions, 0 deletions
diff --git a/lib/gitlab/background_migration/redact_links.rb b/lib/gitlab/background_migration/redact_links.rb
new file mode 100644
index 00000000000..f5d3bcdd517
--- /dev/null
+++ b/lib/gitlab/background_migration/redact_links.rb
@@ -0,0 +1,62 @@
+# frozen_string_literal: true
+# rubocop:disable Style/Documentation
+
+module Gitlab
+  module BackgroundMigration
+    class RedactLinks
+      module Redactable
+        extend ActiveSupport::Concern
+
+        def redact_field!(field)
+          self[field].gsub!(%r{/sent_notifications/\h{32}/unsubscribe}, '/sent_notifications/REDACTED/unsubscribe')
+
+          if self.changed?
+            self.update_columns(field => self[field],
+                                "#{field}_html" => nil)
+          end
+        end
+      end
+
+      class Note < ActiveRecord::Base
+        include EachBatch
+        include Redactable
+
+        self.table_name = 'notes'
+        self.inheritance_column = :_type_disabled
+      end
+
+      class Issue < ActiveRecord::Base
+        include EachBatch
+        include Redactable
+
+        self.table_name = 'issues'
+        self.inheritance_column = :_type_disabled
+      end
+
+      class MergeRequest < ActiveRecord::Base
+        include EachBatch
+        include Redactable
+
+        self.table_name = 'merge_requests'
+        self.inheritance_column = :_type_disabled
+      end
+
+      class Snippet < ActiveRecord::Base
+        include EachBatch
+        include Redactable
+
+        self.table_name = 'snippets'
+        self.inheritance_column = :_type_disabled
+      end
+
+      def perform(model_name, field, start_id, stop_id)
+        link_pattern = "%/sent_notifications/" + ("_" * 32) + "/unsubscribe%"
+        model = "Gitlab::BackgroundMigration::RedactLinks::#{model_name}".constantize
+
+        model.where("#{field} like ?", link_pattern).where(id: start_id..stop_id).each do |resource|
+          resource.redact_field!(field)
+        end
+      end
+    end
+  end
+end