deletors: skip projected resources

Skip attempting to delete projected resources in the APIBinding and
Workspace Resource Deletors. These projected resources will
automatically go away when their underlying resources are deleted.

Signed-off-by: Andy Goldstein <[email protected]>
(cherry picked from commit 6d3c78a)

pkg/informer/informer.go

@@ -42,8 +42,8 @@ import (
 	"k8s.io/client-go/tools/cache"
 	"k8s.io/klog/v2"
 
-	"github.com/kcp-dev/kcp/pkg/apis/tenancy"
 	metadataclient "github.com/kcp-dev/kcp/pkg/metadata"
+	"github.com/kcp-dev/kcp/pkg/projection"
 )
 
 const (
@@ -426,16 +426,17 @@ func (d *DynamicDiscoverySharedInformerFactory) updateInformers() {
 		group := parts[0]
 		version := parts[1]
 		resource := parts[2]
+		gvr := gvrFor(group, version, resource)
 
-		// Don't start a dynamic informer for tenancy.kcp.dev/v1beta1 Workspaces. These are a virtual projection of
-		// data from tenancy.kcp.dev/v1alpha1 ClusterWorkspaces. Starting an informer for them causes problems when
-		// the virtual-workspaces server is deployed separately. See https://github.com/kcp-dev/kcp/issues/1654 for
-		// more details.
-		if group == tenancy.GroupName && version == "v1beta1" && resource == "workspaces" {
+		// Don't start a dynamic informer for projected resources such as tenancy.kcp.dev/v1beta1 Workspaces
+		// (these are a virtual projection of data from tenancy.kcp.dev/v1alpha1 ClusterWorkspaces).
+		// Starting an informer for them causes problems when the virtual-workspaces server is deployed
+		// separately. See https://github.com/kcp-dev/kcp/issues/1654 for more details.
+		if projection.Includes(gvr) {
 			continue
 		}
 
-		latest[gvrFor(group, version, resource)] = struct{}{}
+		latest[gvr] = struct{}{}
 	}
 
 	// Grab a read lock to compare against d.informers to see if we need to start or stop any informers

pkg/projection/projected_apis.go

@@ -0,0 +1,39 @@
+/*
+Copyright 2022 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 projection
+
+import (
+	"k8s.io/apimachinery/pkg/runtime/schema"
+
+	tenancyv1beta1 "github.com/kcp-dev/kcp/pkg/apis/tenancy/v1beta1"
+)
+
+var projectedAPIs map[schema.GroupVersionResource]struct{}
+
+func init() {
+	projectedAPIs = map[schema.GroupVersionResource]struct{}{
+		tenancyv1beta1.SchemeGroupVersion.WithResource("workspaces"): {},
+	}
+}
+
+// Includes returns true if gvr is for a projected API. An API is projected if it is not stored in etcd and instead
+// comes from some other data that is actually stored in etcd. For example, Workspaces (tenancy.kcp.dev/v1beta1) are
+// projected; the real data comes from ClusterWorkspaces (tenancy.kcp.dev/v1alpha1).
+func Includes(gvr schema.GroupVersionResource) bool {
+	_, exists := projectedAPIs[gvr]
+	return exists
+}

pkg/reconciler/apis/apibindingdeletion/apibinding_deletor.go

@@ -29,6 +29,7 @@ import (
 	"k8s.io/klog/v2"
 
 	apisv1alpha1 "github.com/kcp-dev/kcp/pkg/apis/apis/v1alpha1"
+	"github.com/kcp-dev/kcp/pkg/projection"
 )
 
 type gvrDeletionMetadata struct {
@@ -58,6 +59,13 @@ func (c *Controller) deleteAllCRs(ctx context.Context, apibinding *apisv1alpha1.
 				Version:  version,
 			}
 
+			// Don't try to delete projected resources such as tenancy.kcp.dev v1beta1 Workspaces - these are virtual
+			// projections and we shouldn't try to delete them. The projections will disappear when the real underlying
+			// data (e.g. ClusterWorkspaces) are deleted.
+			if projection.Includes(gvr) {
+				continue
+			}
+
 			deletionMetadata, err := c.deleteAllCR(ctx, logicalcluster.From(apibinding), gvr)
 			if err != nil {
 				deleteContentErrs = append(deleteContentErrs, err)

pkg/reconciler/tenancy/clusterworkspacedeletion/deletion/workspace_resource_deletor.go

@@ -52,6 +52,7 @@ import (
 	tenancyv1alpha1 "github.com/kcp-dev/kcp/pkg/apis/tenancy/v1alpha1"
 	conditionsv1alpha1 "github.com/kcp-dev/kcp/pkg/apis/third_party/conditions/apis/conditions/v1alpha1"
 	"github.com/kcp-dev/kcp/pkg/apis/third_party/conditions/util/conditions"
+	"github.com/kcp-dev/kcp/pkg/projection"
 )
 
 const (
@@ -395,6 +396,13 @@ func (d *workspacedResourcesDeleter) deleteAllContent(ctx context.Context, ws *t
 	}
 	deleteContentErrs := []error{}
 	for gvr, verbs := range groupVersionResources {
+		// Don't try to delete projected resources such as tenancy.kcp.dev v1beta1 Workspaces - these are virtual
+		// projections and we shouldn't try to delete them. The projections will disappear when the real underlying
+		// data (e.g. ClusterWorkspaces) are deleted.
+		if projection.Includes(gvr) {
+			continue
+		}
+
 		gvrDeletionMetadata, err := d.deleteAllContentForGroupVersionResource(ctx, wsClusterName, gvr, verbs, workspaceDeletedAt)
 		if err != nil {
 			// If there is an error, hold on to it but proceed with all the remaining