✨ Add Upsync controller

pkg/syncer/spec/spec_controller.go

@@ -46,6 +46,7 @@ import (
 	"k8s.io/client-go/util/workqueue"
 	"k8s.io/klog/v2"
 
+	workloadv1alpha1 "github.com/kcp-dev/kcp/pkg/apis/workload/v1alpha1"
 	"github.com/kcp-dev/kcp/pkg/indexers"
 	ddsif "github.com/kcp-dev/kcp/pkg/informer"
 	"github.com/kcp-dev/kcp/pkg/logging"
@@ -175,6 +176,18 @@ func NewSpecSyncer(syncerLogger logr.Logger, syncTargetClusterName logicalcluste
 				if gvr == namespaceGVR {
 					return
 				}
+				if d, ok := obj.(cache.DeletedFinalStateUnknown); ok {
+					obj = d.Obj
+				}
+				unstrObj, ok := obj.(*unstructured.Unstructured)
+				if !ok {
+					utilruntime.HandleError(fmt.Errorf("resource should be a *unstructured.Unstructured, but was %T", unstrObj))
+					return
+				}
+				if unstrObj.GetLabels()[workloadv1alpha1.ClusterResourceStateLabelPrefix+syncTargetKey] == string(workloadv1alpha1.ResourceStateUpsync) {
+					return
+				}
+
 				key, err := cache.DeletionHandlingMetaNamespaceKeyFunc(obj)
 				if err != nil {
 					utilruntime.HandleError(fmt.Errorf("error getting key for type %T: %w", obj, err))
@@ -188,7 +201,6 @@ func NewSpecSyncer(syncerLogger logr.Logger, syncTargetClusterName logicalcluste
 				logger.V(3).Info("processing delete event")
 
 				var nsLocatorHolder *unstructured.Unstructured
-				var ok bool
 				// Handle namespaced resources
 				if namespace != "" {
 					// Use namespace lister
@@ -214,11 +226,7 @@ func NewSpecSyncer(syncerLogger logr.Logger, syncTargetClusterName logicalcluste
 					}
 				} else {
 					// The nsLocatorHolder is in the resource itself for cluster-scoped resources.
-					nsLocatorHolder, ok = obj.(*unstructured.Unstructured)
-					if !ok {
-						utilruntime.HandleError(fmt.Errorf("unexpected object type: %T", obj))
-						return
-					}
+					nsLocatorHolder = unstrObj
 				}
 				logger = logging.WithObject(logger, nsLocatorHolder)
 

pkg/syncer/status/status_controller.go

@@ -38,6 +38,7 @@ import (
 	"k8s.io/client-go/util/workqueue"
 	"k8s.io/klog/v2"
 
+	workloadv1alpha1 "github.com/kcp-dev/kcp/pkg/apis/workload/v1alpha1"
 	ddsif "github.com/kcp-dev/kcp/pkg/informer"
 	"github.com/kcp-dev/kcp/pkg/logging"
 	"github.com/kcp-dev/kcp/pkg/syncer/shared"
@@ -116,6 +117,15 @@ func NewStatusSyncer(syncerLogger logr.Logger, syncTargetClusterName logicalclus
 				if gvr == namespaceGVR {
 					return
 				}
+				unstrObj, ok := obj.(*unstructured.Unstructured)
+				if !ok {
+					runtime.HandleError(fmt.Errorf("resource should be a *unstructured.Unstructured, but was %T", unstrObj))
+					return
+				}
+				if unstrObj.GetLabels()[workloadv1alpha1.ClusterResourceStateLabelPrefix+syncTargetKey] == string(workloadv1alpha1.ResourceStateUpsync) {
+					return
+				}
+
 				c.AddToQueue(gvr, obj, logger)
 			},
 			UpdateFunc: func(gvr schema.GroupVersionResource, oldObj, newObj interface{}) {
@@ -124,7 +134,9 @@ func NewStatusSyncer(syncerLogger logr.Logger, syncTargetClusterName logicalclus
 				}
 				oldUnstrob := oldObj.(*unstructured.Unstructured)
 				newUnstrob := newObj.(*unstructured.Unstructured)
-
+				if newUnstrob.GetLabels()[workloadv1alpha1.ClusterResourceStateLabelPrefix+syncTargetKey] == string(workloadv1alpha1.ResourceStateUpsync) {
+					return
+				}
 				if !deepEqualFinalizersAndStatus(oldUnstrob, newUnstrob) {
 					c.AddToQueue(gvr, newUnstrob, logger)
 				}
@@ -133,6 +145,18 @@ func NewStatusSyncer(syncerLogger logr.Logger, syncTargetClusterName logicalclus
 				if gvr == namespaceGVR {
 					return
 				}
+				if d, ok := obj.(cache.DeletedFinalStateUnknown); ok {
+					obj = d.Obj
+				}
+				unstrObj, ok := obj.(*unstructured.Unstructured)
+				if !ok {
+					runtime.HandleError(fmt.Errorf("resource should be a *unstructured.Unstructured, but was %T", unstrObj))
+					return
+				}
+				if unstrObj.GetLabels()[workloadv1alpha1.ClusterResourceStateLabelPrefix+syncTargetKey] == string(workloadv1alpha1.ResourceStateUpsync) {
+					return
+				}
+
 				c.AddToQueue(gvr, obj, logger)
 			},
 		})

pkg/syncer/status/status_process.go

@@ -164,6 +164,11 @@ func (c *Controller) process(ctx context.Context, gvr schema.GroupVersionResourc
 	if !ok {
 		return fmt.Errorf("object to synchronize is expected to be Unstructured, but is %T", obj)
 	}
+	if u.GetLabels()[workloadv1alpha1.ClusterResourceStateLabelPrefix+c.syncTargetKey] == string(workloadv1alpha1.ResourceStateUpsync) {
+		logger.V(4).Info("do not update the status in upstream, since the downstream resource is in Upsync mode")
+		return nil
+	}
+
 	return c.updateStatusInUpstream(ctx, gvr, upstreamLister, upstreamNamespace, upstreamName, upstreamClusterName, u)
 }
 

pkg/syncer/syncer.go

@@ -54,6 +54,7 @@ import (
 	"github.com/kcp-dev/kcp/pkg/syncer/resourcesync"
 	"github.com/kcp-dev/kcp/pkg/syncer/spec"
 	"github.com/kcp-dev/kcp/pkg/syncer/status"
+	"github.com/kcp-dev/kcp/pkg/syncer/upsync"
 	. "github.com/kcp-dev/kcp/tmc/pkg/logging"
 )
 
@@ -291,6 +292,12 @@ func StartSyncer(ctx context.Context, cfg *SyncerConfig, numSyncerThreads int, i
 		return err
 	}
 
+	logger.Info("Creating resource upsyncer")
+	upSyncer, err := upsync.NewUpSyncer(logger, logicalcluster.From(syncTarget), cfg.SyncTargetName, syncTargetKey, upstreamUpsyncerClusterClient, downstreamDynamicClient, ddsifForUpstreamUpsyncer, ddsifForDownstream, syncTarget.GetUID())
+	if err != nil {
+		return err
+	}
+
 	// Start and sync informer factories
 	var cacheSyncsForAlwaysRequiredGVRs []cache.InformerSynced
 	for _, alwaysRequired := range []string{"secrets", "namespaces"} {
@@ -326,7 +333,7 @@ func StartSyncer(ctx context.Context, cfg *SyncerConfig, numSyncerThreads int, i
 	go syncTargetGVRSource.Start(ctx, 1)
 	go specSyncer.Start(ctx, numSyncerThreads)
 	go statusSyncer.Start(ctx, numSyncerThreads)
-
+	go upSyncer.Start(ctx, numSyncerThreads)
 	go downstreamNamespaceController.Start(ctx, numSyncerThreads)
 
 	// Create and start GVR-specific controllers through controller managers