Isolate ProjectCacheWorker specific Geo code in prepended module

app/workers/project_cache_worker.rb

@@ -6,6 +6,7 @@
 class ProjectCacheWorker
   include Sidekiq::Worker
   include DedicatedSidekiqQueue
+  prepend EE::Workers::ProjectCacheWorker
 
   LEASE_TIMEOUT = 15.minutes.to_i
 
@@ -32,11 +33,7 @@ class ProjectCacheWorker
       return
     end
 
-    if Gitlab::Geo.secondary?
-      update_geo_caches(project_id)
-    else
-      update_caches(project_id)
-    end
+    update_caches(project_id)
   end
 
   def update_caches(project_id)
@@ -52,18 +49,6 @@ class ProjectCacheWorker
     end
   end
 
-  # Geo should only update Redis based cache, as data store in the database
-  # will be updated on primary and replicated to the secondaries.
-  def update_geo_caches(project_id)
-    project = Project.find(project_id)
-
-    return unless project.repository.exists?
-
-    if project.repository.root_ref
-      project.repository.build_cache
-    end
-  end
-
   def try_obtain_lease_for(project_id)
     self.class.lease_for(project_id).try_obtain
   end

lib/ee/workers/project_cache_worker.rb

+module EE
+  module Workers
+    # Geo specific code for cache re-generation
+    #
+    # This module is intended to encapsulate EE-specific methods
+    # and be **prepended** in the `ProjectCacheWorker` class.
+    module ProjectCacheWorker
+      def update_caches(project_id)
+        if ::Gitlab::Geo.secondary?
+          update_geo_caches(project_id)
+        else
+          super
+        end
+      end
+
+      private
+
+      # Geo should only update Redis based cache, as data store in the database
+      # will be updated on primary and replicated to the secondaries.
+      def update_geo_caches(project_id)
+        project = Project.find(project_id)
+
+        return unless project.repository.exists?
+
+        if project.repository.root_ref
+          project.repository.build_cache
+        end
+      end
+    end
+  end
+end