Denormalize shared runners to CI::PendingBuild

app/models/ci/pending_build.rb

@@ -11,11 +11,48 @@ module Ci
     scope :queued_before, ->(time) { where(arel_table[:created_at].lt(time)) }
 
     def self.upsert_from_build!(build)
-      entry = self.new(build: build, project: build.project, protected: build.protected?)
+      entry = self.new(args_from_build(build))
 
       entry.validate!
 
       self.upsert(entry.attributes.compact, returning: %w[build_id], unique_by: :build_id)
     end
+
+    def self.args_from_build(build)
+      args = {
+        build: build,
+        project: build.project,
+        protected: build.protected?
+      }
+
+      if Feature.enabled?(:ci_pending_builds_maintain_shared_runners_data, type: :development, default_enabled: :yaml)
+        args.merge(instance_runners_enabled: shareable?(build))
+      else
+        args
+      end
+    end
+    private_class_method :args_from_build
+
+    def self.shareable?(build)
+      shared_runner_enabled?(build) &&
+        builds_access_level?(build) &&
+        project_not_removed?(build)
+    end
+    private_class_method :shareable?
+
+    def self.shared_runner_enabled?(build)
+      build.project.shared_runners.exists?
+    end
+    private_class_method :shared_runner_enabled?
+
+    def self.project_not_removed?(build)
+      !build.project.pending_delete?
+    end
+    private_class_method :project_not_removed?
+
+    def self.builds_access_level?(build)
+      build.project.project_feature.builds_access_level.nil? || build.project.project_feature.builds_access_level > 0
+    end
+    private_class_method :builds_access_level?
   end
 end

config/feature_flags/development/ci_pending_builds_maintain_shared_runners_data.yml

+---
+name: ci_pending_builds_maintain_shared_runners_data
+introduced_by_url:
+rollout_issue_url:
+milestone: '14.1'
+type: development
+group: group::pipeline execution
+default_enabled: false

db/migrate/20210705144657_add_instance_runners_enabled_to_ci_pending_build.rb

+# frozen_string_literal: true
+
+class AddInstanceRunnersEnabledToCiPendingBuild < ActiveRecord::Migration[6.1]
+  include Gitlab::Database::MigrationHelpers
+
+  disable_ddl_transaction!
+
+  def up
+    with_lock_retries do
+      add_column :ci_pending_builds, :instance_runners_enabled, :boolean, null: false, default: false
+    end
+  end
+
+  def down
+    with_lock_retries do
+      remove_column :ci_pending_builds, :instance_runners_enabled
+    end
+  end
+end

db/schema_migrations/20210705144657

+9ba27b5e2599262846a06736db72fb0d31dc904e2ef4d167c1ee9530feb6367f
\ No newline at end of file

db/structure.sql

@@ -10833,7 +10833,8 @@ CREATE TABLE ci_pending_builds (
     build_id bigint NOT NULL,
     project_id bigint NOT NULL,
     created_at timestamp with time zone DEFAULT now() NOT NULL,
-    protected boolean DEFAULT false NOT NULL
+    protected boolean DEFAULT false NOT NULL,
+    instance_runners_enabled boolean DEFAULT false NOT NULL
 );
 
 CREATE SEQUENCE ci_pending_builds_id_seq

spec/factories/ci/pending_builds.rb

@@ -5,5 +5,6 @@ FactoryBot.define do
     build factory: :ci_build
     project
     protected { build.protected }
+    instance_runners_enabled { true }
   end
 end

spec/models/ci/pending_build_spec.rb

@@ -29,5 +29,61 @@ RSpec.describe Ci::PendingBuild do
         expect(result.rows.dig(0, 0)).to eq build.id
       end
     end
+
+    context 'when project does not have shared runner' do
+      it 'sets instance_runners_enabled to false' do
+        described_class.upsert_from_build!(build)
+
+        expect(described_class.last.instance_runners_enabled).to be_falsey
+      end
+    end
+
+    context 'when project has shared runner' do
+      let_it_be(:runner) { create(:ci_runner, :instance) }
+
+      context 'when ci_pending_builds_maintain_shared_runners_data is enabled' do
+        it 'sets instance_runners_enabled to true' do
+          described_class.upsert_from_build!(build)
+
+          expect(described_class.last.instance_runners_enabled).to be_truthy
+        end
+
+        context 'when project is about to be deleted' do
+          before do
+            build.project.update!(pending_delete: true)
+          end
+
+          it 'sets instance_runners_enabled to false' do
+            described_class.upsert_from_build!(build)
+
+            expect(described_class.last.instance_runners_enabled).to be_falsey
+          end
+        end
+
+        context 'when builds are disabled' do
+          before do
+            build.project.project_feature.update!(builds_access_level: false)
+          end
+
+          it 'sets instance_runners_enabled to false' do
+            described_class.upsert_from_build!(build)
+
+            expect(described_class.last.instance_runners_enabled).to be_falsey
+          end
+        end
+      end
+
+      context 'when ci_pending_builds_maintain_shared_runners_data is disabled' do
+        before do
+          stub_feature_flags(ci_pending_builds_maintain_shared_runners_data: false)
+        end
+
+        it 'sets instance_runners_enabled to false' do
+          described_class.upsert_from_build!(build)
+
+          expect(described_class.last.instance_runners_enabled).to be_falsey
+        end
+      end
+    end
   end
 end