Swap FK ci_runner_projects to projects for LFK

Swaps FK for ci_runner_projects.project_id to projects

Changelog: changed

db/post_migrate/20220124151949_remove_projects_ci_runner_projects_project_id_fk.rb

+# frozen_string_literal: true
+
+class RemoveProjectsCiRunnerProjectsProjectIdFk < Gitlab::Database::Migration[1.0]
+  disable_ddl_transaction!
+
+  def up
+    return unless foreign_key_exists?(:ci_runner_projects, :projects, name: "fk_4478a6f1e4")
+
+    with_lock_retries do
+      execute('LOCK projects, ci_runner_projects IN ACCESS EXCLUSIVE MODE') if transaction_open?
+
+      remove_foreign_key_if_exists(:ci_runner_projects, :projects, name: "fk_4478a6f1e4")
+    end
+  end
+
+  def down
+    add_concurrent_foreign_key(:ci_runner_projects, :projects, name: "fk_4478a6f1e4", column: :project_id, target_column: :id, on_delete: :cascade)
+  end
+end

db/schema_migrations/20220124151949

+4eb33deb4c2d5ff587f8af57b8296e46911f24a6ed0b2f7ff1f36243f1a9013d
\ No newline at end of file

db/structure.sql

@@ -29369,9 +29369,6 @@ ALTER TABLE ONLY remote_mirrors
 ALTER TABLE ONLY incident_management_timeline_events
     ADD CONSTRAINT fk_4432fc4d78 FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;
 
-ALTER TABLE ONLY ci_runner_projects
-    ADD CONSTRAINT fk_4478a6f1e4 FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;
-
 ALTER TABLE ONLY todos
     ADD CONSTRAINT fk_45054f9c45 FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;
 

lib/gitlab/database/gitlab_loose_foreign_keys.yml

@@ -31,6 +31,10 @@ ci_variables:
   - table: projects
     column: project_id
     on_delete: async_delete
+ci_runner_projects:
+  - table: projects
+    column: project_id
+    on_delete: async_delete
 ci_job_token_project_scope_links:
   - table: users
     column: added_by_id

spec/lib/gitlab/database/no_cross_db_foreign_keys_spec.rb

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

spec/models/ci/runner_project_spec.rb

@@ -6,4 +6,11 @@ RSpec.describe Ci::RunnerProject do
   it_behaves_like 'includes Limitable concern' do
     subject { build(:ci_runner_project, project: create(:project), runner: create(:ci_runner, :project)) }
   end
+
+  context 'loose foreign key on ci_runner_projects.project_id' do
+    it_behaves_like 'cleanup by a loose foreign key' do
+      let!(:parent) { create(:project) }
+      let!(:model) { create(:ci_runner_project, project: parent) }
+    end
+  end
 end