Add state machine to storage moves

Fixes various specs

app/models/project.rb

@@ -2079,13 +2079,7 @@ class Project < ApplicationRecord
       source_storage_name: repository_storage,
       destination_storage_name: new_repository_storage_key
     )
-
-    run_after_commit do
-      ProjectUpdateRepositoryStorageWorker.perform_async(
-        id, new_repository_storage_key,
-        repository_storage_move_id: storage_move.id
-      )
-    end
+    storage_move.schedule!
 
     self.repository_read_only = true
   end

app/models/project_repository_storage_move.rb

@@ -4,16 +4,51 @@
 # project. For example, moving a project to another gitaly node to help
 # balance storage capacity.
 class ProjectRepositoryStorageMove < ApplicationRecord
-  belongs_to :project, inverse_of: :repository_storage_moves
+  include AfterCommitQueue
 
-  enum state: { scheduled: 1, started: 2, finished: 3, failed: 4 }
+  belongs_to :project, inverse_of: :repository_storage_moves
 
   validates :project, presence: true
   validates :state, presence: true
   validates :source_storage_name,
+    on: :create,
     presence: true,
     inclusion: { in: ->(_) { Gitlab.config.repositories.storages.keys } }
   validates :destination_storage_name,
+    on: :create,
     presence: true,
     inclusion: { in: ->(_) { Gitlab.config.repositories.storages.keys } }
+
+  state_machine initial: :initial do
+    event :schedule do
+      transition initial: :scheduled
+    end
+
+    event :start do
+      transition scheduled: :started
+    end
+
+    event :finish do
+      transition started: :finished
+    end
+
+    event :do_fail do
+      transition [:initial, :scheduled, :started] => :failed
+    end
+
+    after_transition initial: :scheduled do |storage_move, _|
+      storage_move.run_after_commit do
+        ProjectUpdateRepositoryStorageWorker.perform_async(
+          storage_move.project_id, storage_move.destination_storage_name,
+          repository_storage_move_id: storage_move.id
+        )
+      end
+    end
+
+    state :initial, value: 1
+    state :scheduled, value: 2
+    state :started, value: 3
+    state :finished, value: 4
+    state :failed, value: 5
+  end
 end

app/services/projects/update_repository_storage_service.rb

@@ -14,7 +14,7 @@ module Projects
     end
 
     def execute
-      repository_storage_move.update!(state: :started)
+      repository_storage_move.start!
 
       raise SameFilesystemError if same_filesystem?(repository.storage, destination_storage_name)
 
@@ -23,7 +23,7 @@ module Projects
       project.transaction do
         mark_old_paths_for_archive
 
-        repository_storage_move.update!(state: :finished)
+        repository_storage_move.finish!
         project.update!(repository_storage: destination_storage_name, repository_read_only: false)
         project.leave_pool_repository
         project.track_project_repository
@@ -35,7 +35,7 @@ module Projects
 
     rescue StandardError => e
       project.transaction do
-        repository_storage_move.update!(state: :failed)
+        repository_storage_move.do_fail!
         project.update!(repository_read_only: false)
       end
 

ee/spec/services/projects/update_repository_storage_service_spec.rb

@@ -17,7 +17,7 @@ describe Projects::UpdateRepositoryStorageService do
         let(:project) { create(:project, :repository, repository_read_only: true) }
         let(:repository) { project.design_repository }
         let(:destination) { 'test_second_storage' }
-        let(:repository_storage_move) { create(:project_repository_storage_move, project: project, destination_storage_name: destination) }
+        let(:repository_storage_move) { create(:project_repository_storage_move, :scheduled, project: project, destination_storage_name: destination) }
 
         before do
           project.design_repository.create_if_not_exists

spec/factories/project_repository_storage_moves.rb

@@ -6,5 +6,9 @@ FactoryBot.define do
 
     source_storage_name { 'default' }
     destination_storage_name { 'default' }
+
+    trait :scheduled do
+      state { ProjectRepositoryStorageMove.state_machines[:state].states[:scheduled].value }
+    end
   end
 end

spec/models/project_repository_storage_move_spec.rb

@@ -31,4 +31,33 @@ RSpec.describe ProjectRepositoryStorageMove, type: :model do
       end
     end
   end
+
+  describe 'state transitions' do
+    using RSpec::Parameterized::TableSyntax
+
+    context 'when in the default state' do
+      subject(:storage_move) { create(:project_repository_storage_move, project: project, destination_storage_name: 'test_second_storage') }
+
+      let(:project) { create(:project) }
+
+      before do
+        stub_storage_settings('test_second_storage' => { 'path' => 'tmp/tests/extra_storage' })
+      end
+
+      context 'and transits to scheduled' do
+        it 'triggers ProjectUpdateRepositoryStorageWorker' do
+          expect(ProjectUpdateRepositoryStorageWorker).to receive(:perform_async).with(project.id, 'test_second_storage', repository_storage_move_id: storage_move.id)
+
+          storage_move.schedule!
+        end
+      end
+
+      context 'and transits to started' do
+        it 'does not allow the transition' do
+          expect { storage_move.start! }
+            .to raise_error(StateMachines::InvalidTransition)
+        end
+      end
+    end
+  end
 end

spec/services/projects/fork_service_spec.rb

@@ -320,8 +320,10 @@ describe Projects::ForkService do
       allow_any_instance_of(Gitlab::Git::Repository).to receive(:checksum)
         .and_return(::Gitlab::Git::BLANK_SHA)
 
-      storage_move = project.repository_storage_moves.create!(
-        source_storage_name: project.repository_storage,
+      storage_move = create(
+        :project_repository_storage_move,
+        :scheduled,
+        project: project,
         destination_storage_name: 'test_second_storage'
       )
       Projects::UpdateRepositoryStorageService.new(storage_move).execute

spec/services/projects/update_repository_storage_service_spec.rb

@@ -18,7 +18,7 @@ describe Projects::UpdateRepositoryStorageService do
     context 'without wiki and design repository' do
       let(:project) { create(:project, :repository, repository_read_only: true, wiki_enabled: false) }
       let(:destination) { 'test_second_storage' }
-      let(:repository_storage_move) { create(:project_repository_storage_move, project: project, destination_storage_name: destination) }
+      let(:repository_storage_move) { create(:project_repository_storage_move, :scheduled, project: project, destination_storage_name: destination) }
       let!(:checksum) { project.repository.checksum }
       let(:project_repository_double) { double(:repository) }
 
@@ -134,7 +134,7 @@ describe Projects::UpdateRepositoryStorageService do
         let(:project) { create(:project, :repository, repository_read_only: true, wiki_enabled: true) }
         let(:repository) { project.wiki.repository }
         let(:destination) { 'test_second_storage' }
-        let(:repository_storage_move) { create(:project_repository_storage_move, project: project, destination_storage_name: destination) }
+        let(:repository_storage_move) { create(:project_repository_storage_move, :scheduled, project: project, destination_storage_name: destination) }
 
         before do
           project.create_wiki