K8s: Fix windows filepath issue in file storage (#81919)

Co-authored-by: Dan Cech <dcech@grafana.com>

pkg/services/apiserver/storage/file/file.go

@@ -37,15 +37,16 @@ var errResourceVersionSetOnCreate = errors.New("resourceVersion should not be se
 
 // Storage implements storage.Interface and storage resources as JSON files on disk.
 type Storage struct {
-	root         string
-	gr           schema.GroupResource
-	codec        runtime.Codec
-	keyFunc      func(obj runtime.Object) (string, error)
-	newFunc      func() runtime.Object
-	newListFunc  func() runtime.Object
-	getAttrsFunc storage.AttrFunc
-	trigger      storage.IndexerFuncs
-	indexers     *cache.Indexers
+	root           string
+	resourcePrefix string
+	gr             schema.GroupResource
+	codec          runtime.Codec
+	keyFunc        func(obj runtime.Object) (string, error)
+	newFunc        func() runtime.Object
+	newListFunc    func() runtime.Object
+	getAttrsFunc   storage.AttrFunc
+	trigger        storage.IndexerFuncs
+	indexers       *cache.Indexers
 
 	watchSet *WatchSet
 }
@@ -78,20 +79,22 @@ func NewStorage(
 	trigger storage.IndexerFuncs,
 	indexers *cache.Indexers,
 ) (storage.Interface, factory.DestroyFunc, error) {
-	if err := ensureDir(resourcePrefix); err != nil {
-		return nil, func() {}, fmt.Errorf("could not establish a writable directory at path=%s", resourcePrefix)
+	root := config.Prefix
+	if err := ensureDir(root); err != nil {
+		return nil, func() {}, fmt.Errorf("could not establish a writable directory at path=%s", root)
 	}
 	ws := NewWatchSet()
 	return &Storage{
-			root:         resourcePrefix,
-			gr:           config.GroupResource,
-			codec:        config.Codec,
-			keyFunc:      keyFunc,
-			newFunc:      newFunc,
-			newListFunc:  newListFunc,
-			getAttrsFunc: getAttrsFunc,
-			trigger:      trigger,
-			indexers:     indexers,
+			root:           root,
+			resourcePrefix: resourcePrefix,
+			gr:             config.GroupResource,
+			codec:          config.Codec,
+			keyFunc:        keyFunc,
+			newFunc:        newFunc,
+			newListFunc:    newListFunc,
+			getAttrsFunc:   getAttrsFunc,
+			trigger:        trigger,
+			indexers:       indexers,
 
 			watchSet: ws,
 		}, func() {
@@ -352,7 +355,9 @@ func (s *Storage) GetList(ctx context.Context, key string, opts storage.ListOpti
 		}
 	}
 
-	objs, err := readDirRecursive(s.codec, key, s.newFunc)
+	dirname := s.dirPath(key)
+
+	objs, err := readDirRecursive(s.codec, dirname, s.newFunc)
 	if err != nil {
 		return err
 	}
@@ -524,5 +529,5 @@ func (s *Storage) validateMinimumResourceVersion(minimumResourceVersion string,
 }
 
 func (s *Storage) nameFromKey(key string) string {
-	return strings.Replace(key, s.root+"/", "", 1)
+	return strings.Replace(key, s.resourcePrefix+"/", "", 1)
 }

pkg/services/apiserver/storage/file/restoptions.go

@@ -3,7 +3,8 @@
 package file
 
 import (
-	"path"
+	"os"
+	"path/filepath"
 	"time"
 
 	"k8s.io/apimachinery/pkg/runtime/schema"
@@ -21,7 +22,7 @@ type RESTOptionsGetter struct {
 
 func NewRESTOptionsGetter(path string, originalStorageConfig storagebackend.Config) *RESTOptionsGetter {
 	if path == "" {
-		path = "/tmp/grafana-apiserver"
+		path = filepath.Join(os.TempDir(), "grafana-apiserver")
 	}
 
 	return &RESTOptionsGetter{path: path, original: originalStorageConfig}
@@ -47,11 +48,12 @@ func (r *RESTOptionsGetter) GetRESTOptions(resource schema.GroupResource) (gener
 	}
 
 	ret := generic.RESTOptions{
-		StorageConfig:             storageConfig,
-		Decorator:                 NewStorage,
-		DeleteCollectionWorkers:   0,
-		EnableGarbageCollection:   false,
-		ResourcePrefix:            path.Join(storageConfig.Prefix, resource.Group, resource.Resource),
+		StorageConfig:           storageConfig,
+		Decorator:               NewStorage,
+		DeleteCollectionWorkers: 0,
+		EnableGarbageCollection: false,
+		// k8s expects forward slashes here, we'll convert them to os path separators in the storage
+		ResourcePrefix:            "/" + resource.Group + "/" + resource.Resource,
 		CountMetricPollPeriod:     1 * time.Second,
 		StorageObjectCountTracker: storageConfig.Config.StorageObjectCountTracker,
 	}

pkg/services/apiserver/storage/file/util.go

@@ -10,12 +10,23 @@ import (
 	"errors"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"k8s.io/apimachinery/pkg/runtime"
 )
 
 func (s *Storage) filePath(key string) string {
-	return key + ".json"
+	// Replace backslashes with underscores to avoid creating bogus subdirectories
+	key = strings.Replace(key, "\\", "_", -1)
+	fileName := filepath.Join(s.root, filepath.Clean(key+".json"))
+	return fileName
+}
+
+func (s *Storage) dirPath(key string) string {
+	// Replace backslashes with underscores to avoid creating bogus subdirectories
+	key = strings.Replace(key, "\\", "_", -1)
+	dirName := filepath.Join(s.root, filepath.Clean(key))
+	return dirName
 }
 
 func writeFile(codec runtime.Codec, path string, obj runtime.Object) error {