add doc.go

pkg/storage/unified/entitybridge/entitybridge.go

@@ -28,7 +28,7 @@ func ProvideResourceServer(db db.DB, cfg *setting.Cfg, features featuremgmt.Feat
 		Tracer: tracer,
 	}
 
-	useEntitySQL := true
+	useEntitySQL := false
 	if useEntitySQL {
 		eDB, err := dbimpl.ProvideEntityDB(db, cfg, features, tracer)
 		if err != nil {

pkg/storage/unified/resource/cdk_backend.go

@@ -69,8 +69,9 @@ type cdkBackend struct {
 	nextRV NextResourceVersion
 	mutex  sync.Mutex
 
-	// Typically one... the server wrapper
-	subscribers []chan *WrittenEvent
+	// Simple watch stream -- NOTE, this only works for single tenant!
+	broadcaster Broadcaster[*WrittenEvent]
+	stream      chan<- *WrittenEvent
 }
 
 func (s *cdkBackend) getPath(key *ResourceKey, rv int64) string {
@@ -123,24 +124,19 @@ func (s *cdkBackend) WriteEvent(ctx context.Context, event WriteEvent) (rv int64
 	}
 
 	// Async notify all subscribers
-	if s.subscribers != nil {
+	if s.stream != nil {
 		go func() {
 			write := &WrittenEvent{
-				WriteEvent: event,
-
+				WriteEvent:      event,
 				Timestamp:       time.Now().UnixMilli(),
 				ResourceVersion: rv,
 			}
-			for _, sub := range s.subscribers {
-				sub <- write
-			}
+			s.stream <- write
 		}()
 	}
-
 	return rv, err
 }
 
-// Read implements ResourceStoreServer.
 func (s *cdkBackend) Read(ctx context.Context, req *ReadRequest) (*ReadResponse, error) {
 	rv := req.ResourceVersion
 
@@ -191,7 +187,6 @@ func isDeletedMarker(raw []byte) bool {
 	return false
 }
 
-// List implements AppendingStore.
 func (s *cdkBackend) PrepareList(ctx context.Context, req *ListRequest) (*ListResponse, error) {
 	resources, err := buildTree(ctx, s, req.Options.Key)
 	if err != nil {
@@ -215,36 +210,21 @@ func (s *cdkBackend) PrepareList(ctx context.Context, req *ListRequest) (*ListRe
 	return rsp, nil
 }
 
-// Watch implements AppendingStore.
 func (s *cdkBackend) WatchWriteEvents(ctx context.Context) (<-chan *WrittenEvent, error) {
-	stream := make(chan *WrittenEvent, 10)
-	{
-		s.mutex.Lock()
-		defer s.mutex.Unlock()
-
-		// Add the event stream
-		s.subscribers = append(s.subscribers, stream)
-	}
-
-	// Wait for context done
-	go func() {
-		// Wait till the context is done
-		<-ctx.Done()
-
-		// Then remove the subscription
-		s.mutex.Lock()
-		defer s.mutex.Unlock()
-
-		// Copy all streams without our listener
-		subs := []chan *WrittenEvent{}
-		for _, sub := range s.subscribers {
-			if sub != stream {
-				subs = append(subs, sub)
-			}
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	if s.broadcaster == nil {
+		var err error
+		s.broadcaster, err = NewBroadcaster(context.Background(), func(c chan<- *WrittenEvent) error {
+			s.stream = c
+			return nil
+		})
+		if err != nil {
+			return nil, err
 		}
-		s.subscribers = subs
-	}()
-	return stream, nil
+	}
+	return s.broadcaster.Subscribe(ctx)
 }
 
 // group > resource > namespace > name > versions

pkg/storage/unified/resource/server_test.go

@@ -2,7 +2,6 @@ package resource
 
 import (
 	"context"
-	"embed"
 	"encoding/json"
 	"fmt"
 	"os"
@@ -39,7 +38,6 @@ func TestSimpleServer(t *testing.T) {
 			Metadata:  fileblob.MetadataDontWrite, // skip
 		})
 		require.NoError(t, err)
-
 		fmt.Printf("ROOT: %s\n\n", tmp)
 	}
 	store, err := NewCDKBackend(ctx, CDKBackendOptions{
@@ -53,7 +51,30 @@ func TestSimpleServer(t *testing.T) {
 	require.NoError(t, err)
 
 	t.Run("playlist happy CRUD paths", func(t *testing.T) {
-		raw := testdata(t, "01_create_playlist.json")
+		raw := []byte(`{
+			"apiVersion": "playlist.grafana.app/v0alpha1",
+			"kind": "Playlist",
+			"metadata": {
+				"name": "fdgsv37qslr0ga",
+				"namespace": "default",
+				"annotations": {
+					"grafana.app/originName": "elsewhere",
+					"grafana.app/originPath": "path/to/item",
+					"grafana.app/originTimestamp": "2024-02-02T00:00:00Z"
+				}
+			},
+			"spec": {
+				"title": "hello",
+				"interval": "5m",
+				"items": [
+					{
+						"type": "dashboard_by_uid",
+						"value": "vmie2cmWz"
+					}
+				]
+			}
+		}`)
+
 		key := &ResourceKey{
 			Group:     "playlist.grafana.app",
 			Resource:  "rrrr", // can be anything :(
@@ -144,13 +165,3 @@ func TestSimpleServer(t *testing.T) {
 		require.Len(t, all.Items, 0) // empty
 	})
 }
-
-//go:embed testdata/*
-var testdataFS embed.FS
-
-func testdata(t *testing.T, filename string) []byte {
-	t.Helper()
-	b, err := testdataFS.ReadFile(`testdata/` + filename)
-	require.NoError(t, err)
-	return b
-}

pkg/storage/unified/resource/testdata/01_create_playlist.json

@@ -1,23 +0,0 @@
-{
-    "apiVersion": "playlist.grafana.app/v0alpha1",
-    "kind": "Playlist",
-    "metadata": {
-        "name": "fdgsv37qslr0ga",
-        "namespace": "default",
-        "annotations": {
-            "grafana.app/originName": "elsewhere",
-            "grafana.app/originPath": "path/to/item",
-            "grafana.app/originTimestamp": "2024-02-02T00:00:00Z"
-        }
-    },
-    "spec": {
-        "title": "hello",
-        "interval": "5m",
-        "items": [
-            {
-                "type": "dashboard_by_uid",
-                "value": "vmie2cmWz"
-            }
-        ]
-    }
-}