Add prometheus metrics on pipeline creation

app/services/ci/create_pipeline_service.rb

@@ -57,6 +57,8 @@ module Ci
 
       cancel_pending_pipelines if project.auto_cancel_pending_pipelines?
 
+      pipeline_created_counter.increment(source: source)
+
       pipeline.tap(&:process!)
     end
 
@@ -131,5 +133,9 @@ module Ci
       pipeline.drop if save
       pipeline
     end
+
+    def pipeline_created_counter
+      @pipeline_created_counter ||= Gitlab::Metrics.counter(:pipelines_created_count, "Pipelines created count")
+    end
   end
 end

changelogs/unreleased/zj-prom-pipeline-count.yml

@@ -0,0 +1,4 @@
+---
+title: Add prometheus metrics on pipeline creation
+merge_request:
+author: