Storage: Add support for sortBy selector (#80680)

* add support for sortBy field selector

* use label selectors instead of field selectors

* set entity_labels on create & update

* make entity server integration tests work

* test fixes

* be more consistent with handling of empty body, meta or status

* workaround for database is locked errors during migration

* fix double import of sqlite3

* rename functions and tidy up

* refactor update

* disable integration tests until we can fix the database locking issue

pkg/services/apiserver/service.go

@@ -277,12 +277,6 @@ func (s *service) start(ctx context.Context) error {
 		return err
 	}
 
-	// support folder selection
-	err = entitystorage.RegisterFieldSelectorSupport(Scheme)
-	if err != nil {
-		return err
-	}
-
 	// Create the server
 	server, err := serverConfig.Complete().New("grafana-apiserver", genericapiserver.NewEmptyDelegate())
 	if err != nil {

pkg/services/apiserver/storage/entity/fieldRequirements.go

@@ -1,76 +0,0 @@
-package entity
-
-import (
-	"fmt"
-	"strings"
-
-	apierrors "k8s.io/apimachinery/pkg/api/errors"
-	"k8s.io/apimachinery/pkg/fields"
-	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/apimachinery/pkg/selection"
-)
-
-const folderAnnoKey = "grafana.app/folder"
-
-type FieldRequirements struct {
-	// Equals folder
-	Folder *string
-}
-
-func ReadFieldRequirements(selector fields.Selector) (FieldRequirements, fields.Selector, error) {
-	requirements := FieldRequirements{}
-
-	if selector == nil {
-		return requirements, selector, nil
-	}
-
-	for _, r := range selector.Requirements() {
-		switch r.Field {
-		case folderAnnoKey:
-			if (r.Operator != selection.Equals) && (r.Operator != selection.DoubleEquals) {
-				return requirements, selector, apierrors.NewBadRequest("only equality is supported in the selectors")
-			}
-			folder := r.Value
-			requirements.Folder = &folder
-		}
-	}
-
-	// use Transform function to remove grafana.app/folder field selector
-	selector, err := selector.Transform(func(field, value string) (string, string, error) {
-		switch field {
-		case folderAnnoKey:
-			return "", "", nil
-		}
-		return field, value, nil
-	})
-
-	return requirements, selector, err
-}
-
-func RegisterFieldSelectorSupport(scheme *runtime.Scheme) error {
-	grafanaFieldSupport := runtime.FieldLabelConversionFunc(
-		func(field, value string) (string, string, error) {
-			if strings.HasPrefix(field, "grafana.app/") {
-				return field, value, nil
-			}
-			return "", "", getBadSelectorError(field)
-		},
-	)
-
-	// Register all the internal types
-	for gvk := range scheme.AllKnownTypes() {
-		if strings.HasSuffix(gvk.Group, ".grafana.app") {
-			err := scheme.AddFieldLabelConversionFunc(gvk, grafanaFieldSupport)
-			if err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
-
-func getBadSelectorError(f string) error {
-	return apierrors.NewBadRequest(
-		fmt.Sprintf("%q is not a known field selector: only %q works", f, folderAnnoKey),
-	)
-}

pkg/services/apiserver/storage/entity/selector.go

@@ -0,0 +1,49 @@
+package entity
+
+import (
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/selection"
+)
+
+const folderAnnoKey = "grafana.app/folder"
+const sortByKey = "grafana.app/sortBy"
+
+type Requirements struct {
+	// Equals folder
+	Folder *string
+	// SortBy is a list of fields to sort by
+	SortBy []string
+}
+
+func ReadLabelSelectors(selector labels.Selector) (Requirements, labels.Selector, error) {
+	requirements := Requirements{}
+	newSelector := labels.NewSelector()
+
+	if selector == nil {
+		return requirements, newSelector, nil
+	}
+
+	labelSelectors, _ := selector.Requirements()
+
+	for _, r := range labelSelectors {
+		switch r.Key() {
+		case folderAnnoKey:
+			if (r.Operator() != selection.Equals) && (r.Operator() != selection.DoubleEquals) {
+				return requirements, newSelector, apierrors.NewBadRequest(folderAnnoKey + " label selector only supports equality")
+			}
+			folder := r.Values().List()[0]
+			requirements.Folder = &folder
+		case sortByKey:
+			if r.Operator() != selection.In {
+				return requirements, newSelector, apierrors.NewBadRequest(sortByKey + " label selector only supports in")
+			}
+			requirements.SortBy = r.Values().List()
+		// add all unregonized label selectors to the new selector list, these will be processed by the entity store
+		default:
+			newSelector = newSelector.Add(r)
+		}
+	}
+
+	return requirements, newSelector, nil
+}

pkg/services/apiserver/storage/entity/storage.go

@@ -229,29 +229,32 @@ func (s *Storage) GetList(ctx context.Context, key string, opts storage.ListOpti
 		// TODO push label/field matching down to storage
 	}
 
+	// translate grafana.app/* label selectors into field requirements
+	requirements, newSelector, err := ReadLabelSelectors(opts.Predicate.Label)
+	if err != nil {
+		return err
+	}
+	if requirements.Folder != nil {
+		req.Folder = *requirements.Folder
+	}
+	if len(requirements.SortBy) > 0 {
+		req.Sort = requirements.SortBy
+	}
+	// Update the selector to remove the unneeded requirements
+	opts.Predicate.Label = newSelector
+
 	// translate "equals" label selectors to storage label conditions
-	requirements, selectable := opts.Predicate.Label.Requirements()
+	labelRequirements, selectable := opts.Predicate.Label.Requirements()
 	if !selectable {
 		return apierrors.NewBadRequest("label selector is not selectable")
 	}
 
-	for _, r := range requirements {
+	for _, r := range labelRequirements {
 		if r.Operator() == selection.Equals {
 			req.Labels[r.Key()] = r.Values().List()[0]
 		}
 	}
 
-	// translate grafana.app/folder field selector to the folder condition
-	fieldRequirements, fieldSelector, err := ReadFieldRequirements(opts.Predicate.Field)
-	if err != nil {
-		return err
-	}
-	if fieldRequirements.Folder != nil {
-		req.Folder = *fieldRequirements.Folder
-	}
-	// Update the field selector to remove the unneeded selectors
-	opts.Predicate.Field = fieldSelector
-
 	rsp, err := s.store.List(ctx, req)
 	if err != nil {
 		return apierrors.NewInternalError(err)