Ensure the pipeline's iid is set before skipping

Issue: gitlab.com/gitlab-org/gitlab/-/issues/325861
MR: gitlab.com/gitlab-org/gitlab/-/merge_requests/59342

config/feature_flags/development/ci_pipeline_ensure_iid_on_skip.yml

+---
+name: ci_pipeline_ensure_iid_on_skip
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/59342
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/327661
+milestone: '13.12'
+type: development
+group: group::code review
+default_enabled: false

lib/gitlab/ci/pipeline/chain/skip.rb

@@ -11,7 +11,16 @@ module Gitlab
 
           def perform!
             if skipped?
-              @pipeline.skip if @command.save_incompleted
+              if @command.save_incompleted
+                if Feature.enabled?(:ci_pipeline_ensure_iid_on_skip, @pipeline.project, default_enabled: :yaml)
+                  # Project iid must be called outside a transaction, so we ensure it is set here
+                  # otherwise it may be set within the state transition transaction of the skip call
+                  # which it will lock the InternalId row for the whole transaction
+                  @pipeline.ensure_project_iid!
+                end
+
+                @pipeline.skip
+              end
             end
           end
 

spec/lib/gitlab/ci/pipeline/chain/skip_spec.rb

@@ -21,17 +21,37 @@ RSpec.describe Gitlab::Ci::Pipeline::Chain::Skip do
     before do
       allow(pipeline).to receive(:git_commit_message)
         .and_return('commit message [ci skip]')
-
-      step.perform!
     end
 
     it 'breaks the chain' do
+      step.perform!
+
       expect(step.break?).to be true
     end
 
     it 'skips the pipeline' do
+      step.perform!
+
       expect(pipeline.reload).to be_skipped
     end
+
+    it 'calls ensure_project_iid explicitly' do
+      expect(pipeline).to receive(:ensure_project_iid!)
+
+      step.perform!
+    end
+
+    context 'when the ci_pipeline_ensure_iid_on_save feature flag is off' do
+      before do
+        stub_feature_flags(ci_pipeline_ensure_iid_on_skip: false)
+      end
+
+      it 'does not call ensure_project_iid explicitly' do
+        expect(pipeline).not_to receive(:ensure_project_iid!)
+
+        step.perform!
+      end
+    end
   end
 
   context 'when pipeline has not been skipped' do