K8s: Folders: Reduce db calls with /api/folders (#103058)

pkg/api/folder.go

@@ -84,6 +84,7 @@ func (hs *HTTPServer) GetFolders(c *contextmodel.ReqContext) response.Response {
 			UID:          c.Query("parentUid"),
 			Permission:   permission,
 			SignedInUser: c.SignedInUser,
+			RefOnly:      true, // nolint:staticcheck
 		}
 
 		folders, err := hs.folderService.GetChildren(c.Req.Context(), q)

pkg/services/folder/folderimpl/unifiedstore.go

@@ -15,6 +15,7 @@ import (
 	claims "github.com/grafana/authlib/types"
 	"github.com/grafana/grafana/pkg/apimachinery/utils"
 	"github.com/grafana/grafana/pkg/storage/unified/resource"
+	"github.com/grafana/grafana/pkg/storage/unified/search"
 
 	"github.com/grafana/grafana/pkg/apis/folder/v0alpha1"
 	"github.com/grafana/grafana/pkg/infra/log"
@@ -236,6 +237,25 @@ func (ss *FolderUnifiedStoreImpl) GetChildren(ctx context.Context, q folder.GetC
 			continue
 		}
 
+		// TODO:  Remove this once we migrate the alerting use case.
+		// This is a temporary flag, and will be removed once we migrate the alerting use case to
+		// expect a folder ref too for children folders.
+		if q.RefOnly { // nolint:staticcheck
+			f := &folder.Folder{
+				ID:        item.Field.GetNestedInt64(search.DASHBOARD_LEGACY_ID),
+				UID:       item.Name,
+				Title:     item.Title,
+				ParentUID: item.Folder,
+			}
+
+			if item.Field.GetNestedString(resource.SEARCH_FIELD_MANAGER_KIND) != "" {
+				f.ManagedBy = utils.ParseManagerKindString(item.Field.GetNestedString(resource.SEARCH_FIELD_MANAGER_KIND))
+			}
+
+			hits = append(hits, f)
+			continue
+		}
+
 		// search only returns a subset of info, get all info of the folder
 		f, err := ss.Get(ctx, folder.GetFolderQuery{UID: &item.Name, OrgID: q.OrgID})
 		if err != nil {

pkg/services/folder/folderimpl/unifiedstore_test.go

@@ -388,4 +388,55 @@ func TestGetChildren(t *testing.T) {
 		require.NoError(t, err)
 		require.Len(t, result, 1)
 	})
+
+	t.Run("should not do get requests for the children if RefOnly is true", func(t *testing.T) {
+		mockCli.On("Search", mock.Anything, orgID, &resource.ResourceSearchRequest{
+			Options: &resource.ListOptions{
+				Fields: []*resource.Requirement{
+					{
+						Key:      resource.SEARCH_FIELD_FOLDER,
+						Operator: string(selection.In),
+						Values:   []string{"folder1"},
+					},
+				},
+			},
+			Limit:  folderSearchLimit, // should default to folderSearchLimit
+			Offset: 0,                 // should be set as limit * (page - 1)
+			Page:   1,                 // should be set to 1 by default
+		}).Return(&resource.ResourceSearchResponse{
+			Results: &resource.ResourceTable{
+				Columns: []*resource.ResourceTableColumnDefinition{
+					{Name: "folder", Type: resource.ResourceTableColumnDefinition_STRING},
+				},
+				Rows: []*resource.ResourceTableRow{
+					{
+						Key:   &resource.ResourceKey{Name: "folder2", Resource: "folder"},
+						Cells: [][]byte{[]byte("folder1")},
+					},
+					{
+						Key:   &resource.ResourceKey{Name: "folder3", Resource: "folder"},
+						Cells: [][]byte{[]byte("folder1")},
+					},
+				},
+			},
+			TotalHits: 1,
+		}, nil).Once()
+		// only get the parent folder in this request
+		mockCli.On("Get", mock.Anything, "folder1", orgID, mock.Anything, mock.Anything).Return(&unstructured.Unstructured{
+			Object: map[string]interface{}{
+				"metadata": map[string]interface{}{"name": "folder1"},
+			},
+		}, nil).Once()
+
+		// don't set page or limit - should be automatically added
+		result, err := store.GetChildren(ctx, folder.GetChildrenQuery{
+			UID:     "folder1",
+			OrgID:   orgID,
+			RefOnly: true, // nolint:staticcheck
+		})
+		require.NoError(t, err)
+		require.Len(t, result, 2)
+		require.Equal(t, "folder2", result[0].UID)
+		require.Equal(t, "folder3", result[1].UID)
+	})
 }

pkg/services/folder/model.go

@@ -221,6 +221,9 @@ type GetChildrenQuery struct {
 
 	// array of folder uids to filter by
 	FolderUIDs []string `json:"-"`
+
+	// Deprecated: this is a temporary flag, and will be removed once we migrate the alerting use case
+	RefOnly bool
 }
 
 type HasEditPermissionInFoldersQuery struct {