Add GitDeduplicationService for deduplication housekeeping

GitDeduplicationService performs idempotent operations on deduplicated
projects.

1 files changed, 90 insertions, 0 deletions

diff --git a/spec/services/projects/git_deduplication_service_spec.rb b/spec/services/projects/git_deduplication_service_spec.rb
new file mode 100644
index 00000000000..3acbc46b473
--- /dev/null
+++ b/spec/services/projects/git_deduplication_service_spec.rb
@@ -0,0 +1,90 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Projects::GitDeduplicationService do
+  include ExclusiveLeaseHelpers
+
+  let(:pool) { create(:pool_repository, :ready) }
+  let(:project) { create(:project, :repository) }
+  let(:lease_key) { "git_deduplication:#{project.id}" }
+  let(:lease_timeout) { Projects::GitDeduplicationService::LEASE_TIMEOUT }
+
+  subject(:service) { described_class.new(project) }
+
+  describe '#execute' do
+    context 'when there is not already a lease' do
+      context 'when the project does not have a pool repository' do
+        it 'calls disconnect_git_alternates' do
+          stub_exclusive_lease(lease_key, timeout: lease_timeout)
+
+          expect(project.repository).to receive(:disconnect_alternates)
+
+          service.execute
+        end
+      end
+
+      context 'when the project has a pool repository' do
+        let(:project) { create(:project, :repository, pool_repository: pool) }
+
+        context 'when the project is a source project' do
+          let(:lease_key) { "git_deduplication:#{pool.source_project.id}" }
+
+          subject(:service) { described_class.new(pool.source_project) }
+
+          it 'calls fetch' do
+            stub_exclusive_lease(lease_key, timeout: lease_timeout)
+            allow(pool.source_project).to receive(:git_objects_poolable?).and_return(true)
+
+            expect(pool.object_pool).to receive(:fetch)
+
+            service.execute
+          end
+
+          it 'does not call fetch if git objects are not poolable' do
+            stub_exclusive_lease(lease_key, timeout: lease_timeout)
+            allow(pool.source_project).to receive(:git_objects_poolable?).and_return(false)
+
+            expect(pool.object_pool).not_to receive(:fetch)
+
+            service.execute
+          end
+
+          it 'does not call fetch if pool and project are not on the same storage' do
+            stub_exclusive_lease(lease_key, timeout: lease_timeout)
+            allow(pool.source_project.repository).to receive(:storage).and_return('special_storage_001')
+
+            expect(pool.object_pool).not_to receive(:fetch)
+
+            service.execute
+          end
+        end
+
+        it 'links the repository to the object pool' do
+          expect(project).to receive(:link_pool_repository)
+
+          service.execute
+        end
+
+        it 'does not link the repository to the object pool if they are not on the same storage' do
+          allow(project.repository).to receive(:storage).and_return('special_storage_001')
+          expect(project).not_to receive(:link_pool_repository)
+
+          service.execute
+        end
+      end
+
+      context 'when a lease is already out' do
+        before do
+          stub_exclusive_lease_taken(lease_key, timeout: lease_timeout)
+        end
+
+        it 'fails when a lease is already out' do
+          expect(service).to receive(:log_error).with('Cannot obtain an exclusive lease. There must be another instance already in execution.')
+
+          service.execute
+        end
+      end
+    end
+  end
+end