1 files changed, 50 insertions, 0 deletions
diff --git a/lib/gitlab/ci/yaml_processor/feature_flags.rb b/lib/gitlab/ci/yaml_processor/feature_flags.rb
new file mode 100644
index 00000000000..f03db9d0e6b
--- /dev/null
+++ b/lib/gitlab/ci/yaml_processor/feature_flags.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    class YamlProcessor
+      module FeatureFlags
+        ACTOR_KEY = 'ci_yaml_processor_feature_flag_actor'
+        NO_ACTOR_VALUE = :no_actor
+
+        NoActorError = Class.new(StandardError)
+        NO_ACTOR_MESSAGE = "Actor not set. Ensure to call `enabled?` inside `with_actor` block"
+
+        class << self
+          # Cache a feature flag actor as thread local variable so
+          # we can have it available later with #enabled?
+          def with_actor(actor)
+            previous = Thread.current[ACTOR_KEY]
+
+            # When actor is `nil` the method `Thread.current[]=` does not
+            # create the ACTOR_KEY. Instead, we want to still save an explicit
+            # value to know that we are within the `with_actor` block.
+            Thread.current[ACTOR_KEY] = actor || NO_ACTOR_VALUE
+
+            yield
+          ensure
+            Thread.current[ACTOR_KEY] = previous
+          end
+
+          # Use this to check if a feature flag is enabled
+          def enabled?(feature_flag)
+            ::Feature.enabled?(feature_flag, current_actor)
+          end
+
+          private
+
+          def current_actor
+            value = Thread.current[ACTOR_KEY] || (raise NoActorError, NO_ACTOR_MESSAGE)
+            return if value == NO_ACTOR_VALUE
+
+            value
+          rescue NoActorError => e
+            Gitlab::ErrorTracking.track_and_raise_for_dev_exception(e)
+
+            nil
+          end
+        end
+      end
+    end
+  end
+end