fix: delete subfolder dangling panels (#113419)

* fix: delete subfolder dangling panels and error if used

* chore: add observation about library panel DeleteInFolders

- logs folders UIDs on DeleteInFolders error

* chore: add integration test for blocking library panel deletion and handling dangling library panels

* chore: fix integration test on mode 4 and 5

pkg/services/folder/folderimpl/folder_unifiedstorage.go

@@ -644,6 +644,21 @@ func (s *Service) deleteFromApiServer(ctx context.Context, cmd *folder.DeleteFol
 			return folder.ErrFolderNotEmpty.Errorf("folder contains %d alert rules", alertRulesInFolder)
 		}
 
+		libraryPanelSrv, ok := s.registry[entity.StandardKindLibraryPanel]
+		if !ok {
+			return folder.ErrInternal.Errorf("no library panel service found in registry")
+		}
+		//	/* TODO: after a decision regarding folder deletion permissions has been made
+		//	(https://github.com/grafana/grafana-enterprise/issues/5144),
+		//	remove the following call to DeleteInFolders
+		//	and remove "user" from the signature of DeleteInFolder in the folder RegistryService.
+		//	Context: https://github.com/grafana/grafana/pull/69149#discussion_r1235057903
+		//	*/
+		// Obs: DeleteInFolders only deletes dangling library panels (not linked to any dashboard) and throws errors if there are connections
+		if err := libraryPanelSrv.DeleteInFolders(ctx, cmd.OrgID, folders, cmd.SignedInUser); err != nil {
+			s.log.Error("failed to delete dangling library panels in folders", "error", err, "folders", strings.Join(folders, ","))
+			return err
+		}
 		// We need a list of dashboard uids inside the folder to delete related dashboards & public dashboards -
 		// we cannot use the dashboard service directly due to circular dependencies, so use the search client to get the dashboards
 		request := &resourcepb.ResourceSearchRequest{

pkg/services/folder/folderimpl/folder_unifiedstorage_test.go

@@ -17,6 +17,7 @@ import (
 	clientrest "k8s.io/client-go/rest"
 
 	folderv1 "github.com/grafana/grafana/apps/folder/pkg/apis/folder/v1beta1"
+	"github.com/grafana/grafana/pkg/api/routing"
 	"github.com/grafana/grafana/pkg/apimachinery/identity"
 	"github.com/grafana/grafana/pkg/apimachinery/utils"
 	"github.com/grafana/grafana/pkg/bus"
@@ -33,6 +34,9 @@ import (
 	dashboardsearch "github.com/grafana/grafana/pkg/services/dashboards/service/search"
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
 	"github.com/grafana/grafana/pkg/services/folder"
+	"github.com/grafana/grafana/pkg/services/folder/foldertest"
+	"github.com/grafana/grafana/pkg/services/libraryelements"
+	"github.com/grafana/grafana/pkg/services/librarypanels"
 	ngstore "github.com/grafana/grafana/pkg/services/ngalert/store"
 	"github.com/grafana/grafana/pkg/services/publicdashboards"
 	"github.com/grafana/grafana/pkg/services/search/model"
@@ -209,6 +213,7 @@ func TestIntegrationFolderServiceViaUnifiedStorage(t *testing.T) {
 				{Action: dashboards.ActionFoldersDelete, Scope: dashboards.ScopeFoldersAll},
 				{Action: dashboards.ActionFoldersRead, Scope: dashboards.ScopeFoldersAll},
 				{Action: accesscontrol.ActionAlertingRuleDelete, Scope: dashboards.ScopeFoldersAll},
+				{Action: accesscontrol.ActionLibraryPanelsDelete, Scope: dashboards.ScopeFoldersAll},
 			}),
 	}}
 
@@ -219,6 +224,16 @@ func TestIntegrationFolderServiceViaUnifiedStorage(t *testing.T) {
 		AccessControl: actest.FakeAccessControl{ExpectedEvaluate: true},
 	}
 
+	mockDashboardService := dashboards.NewFakeDashboardService(t)
+	mockFolderService := foldertest.NewFakeService()
+	elementService := libraryelements.ProvideService(cfg, db, routing.NewRouteRegister(), mockFolderService, featuremgmt.WithFeatures(), actest.FakeAccessControl{ExpectedEvaluate: true}, mockDashboardService, nil, nil)
+	lps := librarypanels.LibraryPanelService{
+		Cfg:                   cfg,
+		SQLStore:              db,
+		LibraryElementService: elementService,
+		FolderService:         mockFolderService,
+	}
+
 	publicDashboardService := publicdashboards.NewFakePublicDashboardServiceWrapper(t)
 
 	fakeK8sClient := new(client.MockK8sHandler)
@@ -237,6 +252,7 @@ func TestIntegrationFolderServiceViaUnifiedStorage(t *testing.T) {
 	}
 
 	require.NoError(t, folderService.RegisterService(alertingStore))
+	require.NoError(t, folderService.RegisterService(lps))
 
 	t.Run("Folder service tests", func(t *testing.T) {
 		t.Run("Given user has no permissions", func(t *testing.T) {
@@ -877,6 +893,17 @@ func TestIntegrationDeleteFoldersFromApiServer(t *testing.T) {
 	}
 	require.NoError(t, service.RegisterService(alertingStore))
 
+	mockDashboardService := dashboards.NewFakeDashboardService(t)
+	mockFolderService := foldertest.NewFakeService()
+	elementService := libraryelements.ProvideService(cfg, db, routing.NewRouteRegister(), mockFolderService, featuremgmt.WithFeatures(), actest.FakeAccessControl{ExpectedEvaluate: true}, mockDashboardService, nil, nil)
+	lps := librarypanels.LibraryPanelService{
+		Cfg:                   cfg,
+		SQLStore:              db,
+		LibraryElementService: elementService,
+		FolderService:         mockFolderService,
+	}
+	require.NoError(t, service.RegisterService(lps))
+
 	t.Run("Should delete folder", func(t *testing.T) {
 		publicDashboardFakeService.On("DeleteByDashboardUIDs", mock.Anything, int64(1), []string{}).Return(nil).Once()
 		dashboardK8sclient.On("Search", mock.Anything, int64(1), mock.Anything).Return(&resourcepb.ResourceSearchResponse{Results: &resourcepb.ResourceTable{}}, nil).Once()