Cancel rendundant pipelines

ee/app/services/merge_trains/refresh_merge_request_service.rb

@@ -15,7 +15,11 @@ module MergeTrains
 
       validate!
 
-      pipeline_created = create_pipeline! if should_create_pipeline?
+      if should_create_pipeline?
+        cancel_pipeline_if_exist
+        pipeline_created = create_pipeline!
+      end
+
       merge! if should_merge?
 
       success(pipeline_created: pipeline_created.present?)
@@ -60,6 +64,12 @@ module MergeTrains
       pipeline_absent? || require_recreate? || stale_pipeline?
     end
 
+    def cancel_pipeline_if_exist
+      return unless pipeline_for_merge_train
+
+      pipeline_for_merge_train.cancel_running
+    end
+
     def create_pipeline!
       result = MergeTrains::CreatePipelineService.new(merge_request.project, merge_user)
         .execute(merge_request, previous_ref)