add --local-topology

When deploying external-provisioner on each node, the topology
information that it needs is most likely just the values reported by
the local CSI driver instance. We can avoid the extra work for
watching Node and CSINode in that case.

cmd/csi-provisioner/csi-provisioner.go

@@ -28,11 +28,14 @@ import (
 
 	"github.com/container-storage-interface/spec/lib/go/csi"
 	flag "github.com/spf13/pflag"
+	v1 "k8s.io/api/core/v1"
+	storagev1 "k8s.io/api/storage/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
-	v1 "k8s.io/client-go/listers/core/v1"
+	listersv1 "k8s.io/client-go/listers/core/v1"
 	storagelistersv1 "k8s.io/client-go/listers/storage/v1"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
@@ -93,6 +96,7 @@ var (
 	nodeDeploymentImmediateBinding = flag.Bool("node-deployment-immediate-binding", true, "Determines whether immediate binding is supported when deployed on each node.")
 	nodeDeploymentBaseDelay        = flag.Duration("node-deployment-base-delay", 20*time.Second, "Determines how long the external-provisioner sleeps initially before trying to own a PVC with immediate binding.")
 	nodeDeploymentMaxDelay         = flag.Duration("node-deployment-max-delay", 60*time.Second, "Determines how long the external-provisioner sleeps at most before trying to own a PVC with immediate binding.")
+	localTopology                  = flag.Bool("local-topology", false, "Instead of watching Node and CSINode objects, use only the topology provided by the CSI driver. Only valid in combination with --node-deployment.")
 
 	featureGates        map[string]bool
 	provisionController *controller.ProvisionController
@@ -239,14 +243,55 @@ func main() {
 		nodeDeployment.NodeInfo = *nodeInfo
 	}
 
-	var nodeLister v1.NodeLister
+	var nodeLister listersv1.NodeLister
 	var csiNodeLister storagelistersv1.CSINodeLister
 	if ctrl.SupportsTopology(pluginCapabilities) {
-		// TODO (?): when deployed on each node with --strict-topology=true, then the topology
-		// code only needs the static information about the local node. We can avoid the overhead
-		// of watching the actual objects by providing just that information.
-		csiNodeLister = factory.Storage().V1().CSINodes().Lister()
-		nodeLister = factory.Core().V1().Nodes().Lister()
+		if *localTopology {
+			if nodeDeployment == nil {
+				klog.Fatal("--local-topology is only valid in combination with --node-deployment")
+			}
+			// Avoid watching in favor of fake, static objects. This is particularly relevant for
+			// Node objects, which can generate significant traffic.
+			csiNode := &storagev1.CSINode{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: nodeDeployment.NodeName,
+				},
+				Spec: storagev1.CSINodeSpec{
+					Drivers: []storagev1.CSINodeDriver{
+						{
+							Name:   provisionerName,
+							NodeID: nodeDeployment.NodeInfo.NodeId,
+						},
+					},
+				},
+			}
+			node := &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: nodeDeployment.NodeName,
+				},
+			}
+			if nodeDeployment.NodeInfo.AccessibleTopology != nil {
+				for key := range nodeDeployment.NodeInfo.AccessibleTopology.Segments {
+					csiNode.Spec.Drivers[0].TopologyKeys = append(csiNode.Spec.Drivers[0].TopologyKeys, key)
+				}
+				node.Labels = nodeDeployment.NodeInfo.AccessibleTopology.Segments
+			}
+			klog.Infof("using local topology with Node = %+v and CSINode = %+v", node, csiNode)
+
+			// We make those fake objects available to the topology code via informers which
+			// never change.
+			stoppedFactory := informers.NewSharedInformerFactory(clientset, 1000*time.Hour)
+			csiNodes := stoppedFactory.Storage().V1().CSINodes()
+			nodes := stoppedFactory.Core().V1().Nodes()
+			csiNodes.Informer().GetStore().Add(csiNode)
+			nodes.Informer().GetStore().Add(node)
+			csiNodeLister = csiNodes.Lister()
+			nodeLister = nodes.Lister()
+
+		} else {
+			csiNodeLister = factory.Storage().V1().CSINodes().Lister()
+			nodeLister = factory.Core().V1().Nodes().Lister()
+		}
 	}
 
 	// -------------------------------