Add latest changes from gitlab-org/gitlab@master

1 files changed, 32 insertions, 0 deletions

diff --git a/lib/gitlab/rack_attack/instrumented_cache_store.rb b/lib/gitlab/rack_attack/instrumented_cache_store.rb
new file mode 100644
index 00000000000..8cf9082384f
--- /dev/null
+++ b/lib/gitlab/rack_attack/instrumented_cache_store.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module RackAttack
+    # This class is a proxy for all Redis calls made by RackAttack. All the
+    # calls are instrumented, then redirected to ::Rails.cache. This class
+    # instruments the standard interfaces of ActiveRecord::Cache defined in
+    # https://github.com/rails/rails/blob/v6.0.3.1/activesupport/lib/active_support/cache.rb#L315
+    #
+    # For more information, please see
+    # https://gitlab.com/gitlab-com/gl-infra/scalability/-/issues/751
+    class InstrumentedCacheStore
+      NOTIFICATION_CHANNEL = 'redis.rack_attack'
+
+      delegate :silence!, :mute, to: :@upstream_store
+
+      def initialize(upstream_store: ::Rails.cache, notifier: ActiveSupport::Notifications)
+        @upstream_store = upstream_store
+        @notifier = notifier
+      end
+
+      [:fetch, :read, :read_multi, :write_multi, :fetch_multi, :write, :delete,
+       :exist?, :delete_matched, :increment, :decrement, :cleanup, :clear].each do |interface|
+        define_method interface do |*args, **k_args, &block|
+          @notifier.instrument(NOTIFICATION_CHANNEL, operation: interface) do
+            @upstream_store.public_send(interface, *args, **k_args, &block) # rubocop:disable GitlabSecurity/PublicSend
+          end
+        end
+      end
+    end
+  end
+end