Fix duplicate disk path in Backfill ProjectRepos

On GitLab.com, we saw numerous duplicate disk entry inserts because
the migration was not taking the routes table into account. We now
implement this in the migration to be consistent.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/56061

lib/gitlab/background_migration/backfill_project_repositories.rb

@@ -83,7 +83,7 @@ module Gitlab
         extend ActiveSupport::Concern
 
         def full_path
-          @full_path ||= build_full_path
+          route&.path || build_full_path
         end
 
         def build_full_path
@@ -99,6 +99,9 @@ module Gitlab
         end
       end
 
+      class Route < ActiveRecord::Base
+      end
+
       # Namespace model.
       class Namespace < ActiveRecord::Base
         self.table_name = 'namespaces'
@@ -110,6 +113,10 @@ module Gitlab
 
         has_many :projects, inverse_of: :parent
         has_many :namespaces, inverse_of: :parent
+
+        def route
+          Route.find_by(source_type: 'Namespace', source_id: self.id)
+        end
       end
 
       # ProjectRegistry model
@@ -165,6 +172,10 @@ module Gitlab
           end
         end
 
+        def route
+          Route.find_by(source_type: 'Project', source_id: self.id)
+        end
+
         def storage
           @storage ||=
             if hashed_storage?

spec/lib/gitlab/background_migration/backfill_project_repositories_spec.rb

@@ -34,6 +34,7 @@ describe Gitlab::BackgroundMigration::BackfillProjectRepositories do
     let!(:project_hashed_storage_2) { create(:project, name: 'bar', path: 'bar', namespace: group, storage_version: 2) }
     let!(:project_legacy_storage_3) { create(:project, name: 'baz', path: 'baz', namespace: group, storage_version: 0) }
     let!(:project_legacy_storage_4) { create(:project, name: 'zoo', path: 'zoo', namespace: group, storage_version: nil) }
+    let!(:project_legacy_storage_5) { create(:project, name: 'test', path: 'test', namespace: group, storage_version: nil) }
 
     describe '.on_hashed_storage' do
       it 'finds projects with repository on hashed storage' do
@@ -47,7 +48,7 @@ describe Gitlab::BackgroundMigration::BackfillProjectRepositories do
       it 'finds projects with repository on legacy storage' do
         projects = described_class.on_legacy_storage.pluck(:id)
 
-        expect(projects).to match_array([project_legacy_storage_3.id, project_legacy_storage_4.id])
+        expect(projects).to match_array([project_legacy_storage_3.id, project_legacy_storage_4.id, project_legacy_storage_5.id])
       end
     end
 
@@ -58,7 +59,7 @@ describe Gitlab::BackgroundMigration::BackfillProjectRepositories do
 
         projects = described_class.without_project_repository.pluck(:id)
 
-        expect(projects).to contain_exactly(project_hashed_storage_2.id, project_legacy_storage_4.id)
+        expect(projects).to contain_exactly(project_hashed_storage_2.id, project_legacy_storage_4.id, project_legacy_storage_5.id)
       end
     end
 
@@ -78,12 +79,21 @@ describe Gitlab::BackgroundMigration::BackfillProjectRepositories do
           expect(project.disk_path).to eq(project_legacy_storage_3.disk_path)
         end
 
+        it 'returns the correct disk_path using the route entry' do
+          project_legacy_storage_5.route.update(path: 'zoo/new-test')
+          project = described_class.find(project_legacy_storage_5.id)
+
+          expect(project.disk_path).to eq('zoo/new-test')
+        end
+
         it 'raises OrphanedNamespaceError when any parent namespace does not exist' do
           subgroup = create(:group, parent: group)
           project_orphaned_namespace = create(:project, name: 'baz', path: 'baz', namespace: subgroup, storage_version: nil)
           subgroup.update_column(:parent_id, Namespace.maximum(:id).succ)
 
           project = described_class.find(project_orphaned_namespace.id)
+          project.route.destroy
+          subgroup.route.destroy
 
           expect { project.disk_path }
             .to raise_error(Gitlab::BackgroundMigration::BackfillProjectRepositories::OrphanedNamespaceError)