Add failure reason enum to CI/CD pipeline model

app/models/ci/pipeline.rb

@@ -71,6 +71,10 @@ module Ci
       auto_devops_source: 2
     }
 
+    enum failure_reason: {
+      unknown_failure: 0
+    }.merge(EE_FAILURE_REASONS)
+
     state_machine :status, initial: :created do
       event :enqueue do
         transition created: :pending

ee/app/models/ee/ci/pipeline.rb

 module EE
   module Ci
     module Pipeline
+
+      EE_FAILURE_REASONS = {
+        activity_limit_exceeded: 20,
+        size_limit_exceeded: 21
+      }.freeze
+
       def predefined_variables
         result = super
         result << { key: 'CI_PIPELINE_SOURCE', value: source.to_s, public: true }

spec/ee/spec/models/ee/ci/pipeline_spec.rb

+require 'spec_helper'
+
+describe Ci::Pipeline do
+  describe '.failure_reasons' do
+    it 'contains failure reasons about exceeded limits' do
+      expect(described_class.failure_reasons)
+        .to include 'activity_limit_exceeded', 'size_limit_exceeded'
+    end
+  end
+end