Replicate logicalclusters containing synctargets

Signed-off-by: David Festal <[email protected]>

Author: davidfestal

pkg/reconciler/workload/replicatelogicalcluster/replicatelogicalcluster_controller.go

@@ -0,0 +1,105 @@
+/*
+Copyright 2023 The KCP Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package replicatelogicalcluster
+
+import (
+	"fmt"
+
+	kcpcache "github.com/kcp-dev/apimachinery/v2/pkg/cache"
+	"github.com/kcp-dev/logicalcluster/v3"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/client-go/tools/cache"
+
+	"github.com/kcp-dev/kcp/pkg/reconciler/cache/labellogicalcluster"
+	"github.com/kcp-dev/kcp/pkg/reconciler/cache/replication"
+	corev1alpha1 "github.com/kcp-dev/kcp/sdk/apis/core/v1alpha1"
+	"github.com/kcp-dev/kcp/sdk/apis/workload"
+	workloadv1alpha1 "github.com/kcp-dev/kcp/sdk/apis/workload/v1alpha1"
+	kcpclientset "github.com/kcp-dev/kcp/sdk/client/clientset/versioned/cluster"
+	corev1alpha1informers "github.com/kcp-dev/kcp/sdk/client/informers/externalversions/core/v1alpha1"
+	workloadv1alpha1informers "github.com/kcp-dev/kcp/sdk/client/informers/externalversions/workload/v1alpha1"
+)
+
+const (
+	ControllerName = "kcp-workload-replicate-logicalcluster"
+)
+
+// NewController returns a new controller for labelling LogicalClusters that should be replicated.
+
+func NewController(
+	kcpClusterClient kcpclientset.ClusterInterface,
+	logicalClusterInformer corev1alpha1informers.LogicalClusterClusterInformer,
+	syncTargetInformer workloadv1alpha1informers.SyncTargetClusterInformer,
+) labellogicalcluster.Controller {
+	logicalClusterLister := logicalClusterInformer.Lister()
+	syncTargetIndexer := syncTargetInformer.Informer().GetIndexer()
+
+	c := labellogicalcluster.NewController(
+		ControllerName,
+		workload.GroupName,
+		func(cluster *corev1alpha1.LogicalCluster) bool {
+			// If there are any SyncTargets for this logical cluster, then the LogicalCluster object should be replicated.
+			keys, err := syncTargetIndexer.IndexKeys(kcpcache.ClusterIndexName, kcpcache.ClusterIndexKey(logicalcluster.From(cluster)))
+			if err != nil {
+				runtime.HandleError(fmt.Errorf("failed to list SyncTargets: %v", err))
+				return false
+			}
+			return len(keys) > 0
+		},
+		kcpClusterClient,
+		logicalClusterInformer,
+	)
+
+	// enqueue the logical cluster every time the APIExport changes
+	enqueueSyncTarget := func(obj interface{}) {
+		if tombstone, ok := obj.(cache.DeletedFinalStateUnknown); ok {
+			obj = tombstone.Obj
+		}
+
+		syncTarget, ok := obj.(*workloadv1alpha1.SyncTarget)
+		if !ok {
+			runtime.HandleError(fmt.Errorf("unexpected object type: %T", obj))
+			return
+		}
+
+		cluster, err := logicalClusterLister.Cluster(logicalcluster.From(syncTarget)).Get(corev1alpha1.LogicalClusterName)
+		if err != nil && !apierrors.IsNotFound(err) {
+			runtime.HandleError(fmt.Errorf("failed to get logical cluster: %v", err))
+			return
+		} else if apierrors.IsNotFound(err) {
+			return
+		}
+
+		c.EnqueueLogicalCluster(cluster, "reason", "SyncTarget changed", "synctarget", syncTarget.Name)
+	}
+
+	syncTargetInformer.Informer().AddEventHandler(cache.FilteringResourceEventHandler{
+		FilterFunc: replication.IsNoSystemClusterName,
+		Handler: cache.ResourceEventHandlerFuncs{
+			AddFunc: func(obj interface{}) {
+				enqueueSyncTarget(obj)
+			},
+			DeleteFunc: func(obj interface{}) {
+				enqueueSyncTarget(obj)
+			},
+		},
+	})
+
+	return c
+}

tmc/pkg/server/controllers.go

@@ -39,6 +39,7 @@ import (
 	workloadplacement "github.com/kcp-dev/kcp/pkg/reconciler/workload/placement"
 	workloadreplicateclusterrole "github.com/kcp-dev/kcp/pkg/reconciler/workload/replicateclusterrole"
 	workloadreplicateclusterrolebinding "github.com/kcp-dev/kcp/pkg/reconciler/workload/replicateclusterrolebinding"
+	workloadreplicatelogicalcluster "github.com/kcp-dev/kcp/pkg/reconciler/workload/replicatelogicalcluster"
 	workloadresource "github.com/kcp-dev/kcp/pkg/reconciler/workload/resource"
 	synctargetcontroller "github.com/kcp-dev/kcp/pkg/reconciler/workload/synctarget"
 	"github.com/kcp-dev/kcp/pkg/reconciler/workload/synctargetexports"
@@ -459,3 +460,30 @@ func (s *Server) installWorkloadReplicateClusterRoleBindingControllers(ctx conte
 		return nil
 	})
 }
+
+func (s *Server) installWorkloadReplicateLogicalClusterControllers(ctx context.Context, config *rest.Config) error {
+	config = rest.CopyConfig(config)
+	config = rest.AddUserAgent(config, workloadreplicatelogicalcluster.ControllerName)
+	kcpClusterClient, err := kcpclientset.NewForConfig(config)
+	if err != nil {
+		return err
+	}
+
+	c := workloadreplicatelogicalcluster.NewController(
+		kcpClusterClient,
+		s.Core.KcpSharedInformerFactory.Core().V1alpha1().LogicalClusters(),
+		s.Core.KcpSharedInformerFactory.Workload().V1alpha1().SyncTargets(),
+	)
+
+	return s.Core.AddPostStartHook(postStartHookName(workloadreplicatelogicalcluster.ControllerName), func(hookContext genericapiserver.PostStartHookContext) error {
+		logger := klog.FromContext(ctx).WithValues("postStartHook", postStartHookName(workloadreplicatelogicalcluster.ControllerName))
+		if err := s.Core.WaitForSync(hookContext.StopCh); err != nil {
+			logger.Error(err, "failed to finish post-start-hook")
+			return nil // don't klog.Fatal. This only happens when context is cancelled.
+		}
+
+		go c.Start(goContext(hookContext), 2)
+
+		return nil
+	})
+}

tmc/pkg/server/server.go

@@ -110,6 +110,10 @@ func (s *Server) Run(ctx context.Context) error {
 		if err := s.installWorkloadReplicateClusterRoleBindingControllers(ctx, controllerConfig); err != nil {
 			return err
 		}
+
+		if err := s.installWorkloadReplicateLogicalClusterControllers(ctx, controllerConfig); err != nil {
+			return err
+		}
 	}
 
 	if s.Options.Core.Controllers.EnableAll || enabled.Has("resource-scheduler") {