Remvoe disable_ddl_transaction! and redandant RecordNotUnique exception rescue

db/migrate/20180424160449_add_pipeline_iid_to_ci_pipelines.rb

@@ -3,8 +3,6 @@ class AddPipelineIidToCiPipelines < ActiveRecord::Migration
 
   DOWNTIME = false
 
-  disable_ddl_transaction!
-
   def up
     add_column :ci_pipelines, :iid, :integer
   end

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

@@ -23,7 +23,7 @@ module Gitlab
                 end
               end
             end
-          rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotUnique => e
+          rescue ActiveRecord::RecordInvalid => e
             error("Failed to persist the pipeline: #{e}")
           end
 

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

@@ -37,17 +37,6 @@ describe Gitlab::Ci::Pipeline::Chain::Create do
   end
 
   context 'when pipeline has validation errors' do
-    shared_examples_for 'expectations' do
-      it 'breaks the chain' do
-        expect(step.break?).to be true
-      end
-
-      it 'appends validation error' do
-        expect(pipeline.errors.to_a)
-          .to include /Failed to persist the pipeline/
-      end
-    end
-
     context 'when ref is nil' do
       let(:pipeline) do
         build(:ci_pipeline, project: project, ref: nil)
@@ -57,18 +46,14 @@ describe Gitlab::Ci::Pipeline::Chain::Create do
         step.perform!
       end
 
-      it_behaves_like 'expectations'
+      it 'breaks the chain' do
+        expect(step.break?).to be true
       end
 
-    context 'when pipeline has a duplicate iid' do
-      before do
-        allow_any_instance_of(Ci::Pipeline).to receive(:ensure_project_iid!) { |p| p.send(:write_attribute, :iid, 1) }
-        create(:ci_pipeline, project: project)
-
-        step.perform!
+      it 'appends validation error' do
+        expect(pipeline.errors.to_a)
+          .to include /Failed to persist the pipeline/
       end
-
-      it_behaves_like 'expectations'
     end
   end
 end