1 files changed, 70 insertions, 0 deletions
diff --git a/app/services/ci/pipeline_creation/cancel_redundant_pipelines_service.rb b/app/services/ci/pipeline_creation/cancel_redundant_pipelines_service.rb
new file mode 100644
index 00000000000..48c3e6490ae
--- /dev/null
+++ b/app/services/ci/pipeline_creation/cancel_redundant_pipelines_service.rb
@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+
+module Ci
+  module PipelineCreation
+    class CancelRedundantPipelinesService
+      include Gitlab::Utils::StrongMemoize
+
+      BATCH_SIZE = 25
+
+      def initialize(pipeline)
+        @pipeline = pipeline
+        @project = @pipeline.project
+      end
+
+      # rubocop: disable CodeReuse/ActiveRecord
+      def execute
+        return if pipeline.parent_pipeline? # skip if child pipeline
+        return unless project.auto_cancel_pending_pipelines?
+
+        Gitlab::OptimisticLocking
+        .retry_lock(parent_and_child_pipelines, name: 'cancel_pending_pipelines') do |cancelables|
+          cancelables.select(:id).each_batch(of: BATCH_SIZE) do |cancelables_batch|
+            auto_cancel_interruptible_pipelines(cancelables_batch.ids)
+          end
+        end
+      end
+
+      private
+
+      attr_reader :pipeline, :project
+
+      def parent_auto_cancelable_pipelines
+        project.all_pipelines
+          .created_after(1.week.ago)
+          .for_ref(pipeline.ref)
+          .where_not_sha(project.commit(pipeline.ref).try(:id))
+          .where("created_at < ?", pipeline.created_at)
+          .ci_sources
+      end
+
+      def parent_and_child_pipelines
+        Ci::Pipeline.object_hierarchy(parent_auto_cancelable_pipelines, project_condition: :same)
+          .base_and_descendants
+          .alive_or_scheduled
+      end
+      # rubocop: enable CodeReuse/ActiveRecord
+
+      def auto_cancel_interruptible_pipelines(pipeline_ids)
+        ::Ci::Pipeline
+          .id_in(pipeline_ids)
+          .with_only_interruptible_builds
+          .each do |cancelable_pipeline|
+            Gitlab::AppLogger.info(
+              class: self.class.name,
+              message: "Pipeline #{pipeline.id} auto-canceling pipeline #{cancelable_pipeline.id}",
+              canceled_pipeline_id: cancelable_pipeline.id,
+              canceled_by_pipeline_id: pipeline.id,
+              canceled_by_pipeline_source: pipeline.source
+            )
+
+            # cascade_to_children not needed because we iterate through descendants here
+            cancelable_pipeline.cancel_running(
+              auto_canceled_by_pipeline_id: pipeline.id,
+              cascade_to_children: false
+            )
+          end
+      end
+    end
+  end
+end