Swap FK ci_sources_projects to projects for LFK

Swaps FK for ci_sources_projects.source_project_id to projects

Changelog: changed

db/post_migrate/20220126202654_remove_projects_ci_sources_projects_source_project_id_fk.rb

+# frozen_string_literal: true
+
+class RemoveProjectsCiSourcesProjectsSourceProjectIdFk < Gitlab::Database::Migration[1.0]
+  disable_ddl_transaction!
+
+  def up
+    return unless foreign_key_exists?(:ci_sources_projects, :projects, name: "fk_rails_64b6855cbc")
+
+    with_lock_retries do
+      execute('LOCK projects, ci_sources_projects IN ACCESS EXCLUSIVE MODE') if transaction_open?
+
+      remove_foreign_key_if_exists(:ci_sources_projects, :projects, name: "fk_rails_64b6855cbc")
+    end
+  end
+
+  def down
+    add_concurrent_foreign_key(:ci_sources_projects, :projects, name: "fk_rails_64b6855cbc", column: :source_project_id, target_column: :id, on_delete: :cascade)
+  end
+end

db/schema_migrations/20220126202654

+6067e4e22e49548496454b48171f8168f7d5bf626fedab4351e2a37a3f85731b
\ No newline at end of file

db/structure.sql

@@ -30607,9 +30607,6 @@ ALTER TABLE ONLY reviews
 ALTER TABLE ONLY operations_feature_flags
     ADD CONSTRAINT fk_rails_648e241be7 FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;
 
-ALTER TABLE ONLY ci_sources_projects
-    ADD CONSTRAINT fk_rails_64b6855cbc FOREIGN KEY (source_project_id) REFERENCES projects(id) ON DELETE CASCADE;
-
 ALTER TABLE ONLY board_group_recent_visits
     ADD CONSTRAINT fk_rails_64bfc19bc5 FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE;
 

ee/spec/models/ci/sources/project_spec.rb

@@ -13,4 +13,11 @@ RSpec.describe Ci::Sources::Project do
 
     it { is_expected.to validate_uniqueness_of(:pipeline_id).scoped_to(:source_project_id) }
   end
+
+  context 'loose foreign key on ci_sources_projects.source_project_id' do
+    it_behaves_like 'cleanup by a loose foreign key' do
+      let!(:parent) { create(:project) }
+      let!(:model) { create(:ci_sources_project, source_project: parent) }
+    end
+  end
 end

lib/gitlab/database/gitlab_loose_foreign_keys.yml

@@ -80,6 +80,10 @@ ci_namespace_mirrors:
   - table: namespaces
     column: namespace_id
     on_delete: async_delete
+ci_sources_projects:
+  - table: projects
+    column: source_project_id
+    on_delete: async_delete
 ci_build_report_results:
   - table: projects
     column: project_id

spec/lib/gitlab/database/no_cross_db_foreign_keys_spec.rb

@@ -27,7 +27,6 @@ RSpec.describe 'cross-database foreign keys' do
       ci_resource_groups.project_id
       ci_runner_namespaces.namespace_id
       ci_running_builds.project_id
-      ci_sources_projects.source_project_id
       ci_stages.project_id
       ci_unit_tests.project_id
     ).freeze