fix(kds): fix the case when webhook/db reject resource

pkg/kds/v2/server/resource_retry_forcer.go

@@ -46,12 +46,13 @@ import (
 // We cannot simply invalidate existing snapshot because versions are also set in StreamState
 type kdsRetryForcer struct {
 	util_xds_v3.NoopCallbacks
-	forceFn func(*envoy_core.Node, model.ResourceType)
-	log     logr.Logger
-	nodes   map[xds.StreamID]*envoy_core.Node
-	backoff time.Duration
-	emitter events.Emitter
-	hasher  envoy_cache.NodeHash
+	forceFn       func(*envoy_core.Node, model.ResourceType)
+	log           logr.Logger
+	nodes         map[xds.StreamID]*envoy_core.Node
+	backoff       time.Duration
+	emitter       events.Emitter
+	hasher        envoy_cache.NodeHash
+	streamToDelay map[xds.StreamID]bool
 
 	sync.Mutex
 }
@@ -64,12 +65,13 @@ func newKdsRetryForcer(
 	hasher envoy_cache.NodeHash,
 ) *kdsRetryForcer {
 	return &kdsRetryForcer{
-		forceFn: forceFn,
-		log:     log,
-		nodes:   map[xds.StreamID]*envoy_core.Node{},
-		backoff: backoff,
-		emitter: emitter,
-		hasher:  hasher,
+		forceFn:       forceFn,
+		log:           log,
+		nodes:         map[xds.StreamID]*envoy_core.Node{},
+		backoff:       backoff,
+		emitter:       emitter,
+		hasher:        hasher,
+		streamToDelay: map[int64]bool{},
 	}
 }
 
@@ -95,10 +97,13 @@ func (r *kdsRetryForcer) OnStreamDeltaRequest(streamID xds.StreamID, request *en
 	if !ok {
 		node = request.Node
 		r.nodes[streamID] = node
+		// store information about NACK resources, to delete force retries once ACK
+	}
+	if _, found := r.streamToDelay[streamID]; !found {
+		r.streamToDelay[streamID] = true
 	}
 	r.Unlock()
 	r.log.Info("received NACK, will retry", "nodeID", r.hasher.ID(request.Node), "type", request.TypeUrl, "err", request.GetErrorDetail().GetMessage(), "backoff", r.backoff)
-	time.Sleep(r.backoff)
 	r.forceFn(node, model.ResourceType(request.TypeUrl))
 	r.emitter.Send(events.TriggerKDSResyncEvent{
 		Type:   model.ResourceType(request.TypeUrl),
@@ -107,3 +112,15 @@ func (r *kdsRetryForcer) OnStreamDeltaRequest(streamID xds.StreamID, request *en
 	r.log.V(1).Info("forced the new verion of resources", "nodeID", node.Id, "type", request.TypeUrl)
 	return nil
 }
+
+func (r *kdsRetryForcer) OnStreamDeltaResponse(streamID int64, req *envoy_sd.DeltaDiscoveryRequest, resp *envoy_sd.DeltaDiscoveryResponse) {
+	r.Lock()
+	_, found := r.streamToDelay[streamID]
+	r.Unlock()
+	if found {
+		time.Sleep(r.backoff)
+		r.Lock()
+		delete(r.streamToDelay, streamID)
+		r.Unlock()
+	}
+}