Adds Rollback functionality to HashedStorage migration

We are adding sidekiq workers and service classes to allow to rollback
a hashed storage migration. There are some refactoring involved as well
as part of the code can be reused by both the migration and the rollback
logic.

1 files changed, 50 insertions, 0 deletions

diff --git a/spec/workers/project_rollback_hashed_storage_worker_spec.rb b/spec/workers/project_rollback_hashed_storage_worker_spec.rb
new file mode 100644
index 00000000000..aed7493763d
--- /dev/null
+++ b/spec/workers/project_rollback_hashed_storage_worker_spec.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe ProjectRollbackHashedStorageWorker, :clean_gitlab_redis_shared_state do
+  include ExclusiveLeaseHelpers
+
+  describe '#perform' do
+    let(:project) { create(:project, :empty_repo) }
+    let(:lease_key) { "project_migrate_hashed_storage_worker:#{project.id}" }
+    let(:lease_timeout) { described_class::LEASE_TIMEOUT }
+    let(:rollback_service) { ::Projects::HashedStorage::RollbackService }
+
+    it 'skips when project no longer exists' do
+      expect(rollback_service).not_to receive(:new)
+
+      subject.perform(-1)
+    end
+
+    it 'skips when project is pending delete' do
+      pending_delete_project = create(:project, :empty_repo, pending_delete: true)
+
+      expect(rollback_service).not_to receive(:new)
+
+      subject.perform(pending_delete_project.id)
+    end
+
+    it 'delegates rollback to service class when have exclusive lease' do
+      stub_exclusive_lease(lease_key, 'uuid', timeout: lease_timeout)
+
+      service_spy = spy
+
+      allow(rollback_service)
+        .to receive(:new).with(project, project.disk_path, logger: subject.logger)
+        .and_return(service_spy)
+
+      subject.perform(project.id)
+
+      expect(service_spy).to have_received(:execute)
+    end
+
+    it 'skips when it cant acquire the exclusive lease' do
+      stub_exclusive_lease_taken(lease_key, timeout: lease_timeout)
+
+      expect(rollback_service).not_to receive(:new)
+
+      subject.perform(project.id)
+    end
+  end
+end