Redo "Add metadata prefetch support."

Makefile

@@ -29,10 +29,12 @@ IDENTITY_PROVIDER ?= $(shell kubectl get --raw /.well-known/openid-configuration
 DRIVER_BINARY = gcs-fuse-csi-driver
 SIDECAR_BINARY = gcs-fuse-csi-driver-sidecar-mounter
 WEBHOOK_BINARY = gcs-fuse-csi-driver-webhook
+PREFETCH_BINARY = gcs-fuse-csi-driver-metadata-prefetch
 
 DRIVER_IMAGE = ${REGISTRY}/${DRIVER_BINARY}
 SIDECAR_IMAGE = ${REGISTRY}/${SIDECAR_BINARY}
 WEBHOOK_IMAGE = ${REGISTRY}/${WEBHOOK_BINARY}
+PREFETCH_IMAGE = ${REGISTRY}/${PREFETCH_BINARY}
 
 DOCKER_BUILDX_ARGS ?= --push --builder multiarch-multiplatform-builder --build-arg STAGINGVERSION=${STAGINGVERSION}
 ifneq ("$(shell docker buildx build --help | grep 'provenance')", "")
@@ -46,7 +48,7 @@ $(info DRIVER_IMAGE is ${DRIVER_IMAGE})
 $(info SIDECAR_IMAGE is ${SIDECAR_IMAGE})
 $(info WEBHOOK_IMAGE is ${WEBHOOK_IMAGE})
 
-all: driver sidecar-mounter webhook
+all: driver sidecar-mounter webhook metadata-prefetch
 
 driver:
 	mkdir -p ${BINDIR}
@@ -56,6 +58,10 @@ sidecar-mounter:
 	mkdir -p ${BINDIR}
 	CGO_ENABLED=0 GOOS=linux GOARCH=$(shell dpkg --print-architecture) go build -mod vendor -ldflags "${LDFLAGS}" -o ${BINDIR}/${SIDECAR_BINARY} cmd/sidecar_mounter/main.go
 
+metadata-prefetch:
+	mkdir -p ${BINDIR}
+	CGO_ENABLED=0 GOOS=linux GOARCH=$(shell dpkg --print-architecture) go build -mod vendor -ldflags "${LDFLAGS}" -o ${BINDIR}/${PREFETCH_BINARY} cmd/metadata_prefetch/main.go
+
 webhook:
 	mkdir -p ${BINDIR}
 	CGO_ENABLED=0 GOOS=linux GOARCH=$(shell dpkg --print-architecture) go build -mod vendor -ldflags "${LDFLAGS}" -o ${BINDIR}/${WEBHOOK_BINARY} cmd/webhook/main.go
@@ -129,18 +135,27 @@ ifeq (${BUILD_ARM}, true)
 	make build-image-linux-arm64
 	docker manifest create ${DRIVER_IMAGE}:${STAGINGVERSION} ${DRIVER_IMAGE}:${STAGINGVERSION}_linux_amd64 ${DRIVER_IMAGE}:${STAGINGVERSION}_linux_arm64
 	docker manifest create ${SIDECAR_IMAGE}:${STAGINGVERSION} ${SIDECAR_IMAGE}:${STAGINGVERSION}_linux_amd64 ${SIDECAR_IMAGE}:${STAGINGVERSION}_linux_arm64
+	docker manifest create ${PREFETCH_IMAGE}:${STAGINGVERSION} ${PREFETCH_IMAGE}:${STAGINGVERSION}_linux_amd64 ${PREFETCH_IMAGE}:${STAGINGVERSION}_linux_arm64
 else
 	docker manifest create ${DRIVER_IMAGE}:${STAGINGVERSION} ${DRIVER_IMAGE}:${STAGINGVERSION}_linux_amd64
 	docker manifest create ${SIDECAR_IMAGE}:${STAGINGVERSION} ${SIDECAR_IMAGE}:${STAGINGVERSION}_linux_amd64
+	docker manifest create ${PREFETCH_IMAGE}:${STAGINGVERSION} ${PREFETCH_IMAGE}:${STAGINGVERSION}_linux_amd64
 endif
 
 	docker manifest create ${WEBHOOK_IMAGE}:${STAGINGVERSION} ${WEBHOOK_IMAGE}:${STAGINGVERSION}_linux_amd64
 
 	docker manifest push --purge ${DRIVER_IMAGE}:${STAGINGVERSION}
 	docker manifest push --purge ${SIDECAR_IMAGE}:${STAGINGVERSION}
+	docker manifest push --purge ${PREFETCH_IMAGE}:${STAGINGVERSION}
 	docker manifest push --purge ${WEBHOOK_IMAGE}:${STAGINGVERSION}
 
 build-image-linux-amd64:
+	docker buildx build ${DOCKER_BUILDX_ARGS} \
+		--file ./cmd/metadata_prefetch/Dockerfile \
+		--tag ${PREFETCH_IMAGE}:${STAGINGVERSION}_linux_amd64 \
+		--platform linux/amd64 \
+		--build-arg TARGETPLATFORM=linux/amd64 .
+
 	docker buildx build \
 		--file ./cmd/csi_driver/Dockerfile \
 		--tag validation_linux_amd64 \
@@ -164,6 +179,12 @@ build-image-linux-amd64:
 		--platform linux/amd64 .
 
 build-image-linux-arm64:
+	docker buildx build ${DOCKER_BUILDX_ARGS} \
+		--file ./cmd/metadata_prefetch/Dockerfile \
+		--tag ${PREFETCH_IMAGE}:${STAGINGVERSION}_linux_arm64 \
+		--platform linux/arm64 \
+		--build-arg TARGETPLATFORM=linux/arm64 .
+
 	docker buildx build \
 		--file ./cmd/csi_driver/Dockerfile \
 		--tag validation_linux_arm64 \
@@ -198,6 +219,7 @@ generate-spec-yaml:
 	cd ./deploy/overlays/${OVERLAY}; ${BINDIR}/kustomize edit set image gke.gcr.io/gcs-fuse-csi-driver=${DRIVER_IMAGE}:${STAGINGVERSION};
 	cd ./deploy/overlays/${OVERLAY}; ${BINDIR}/kustomize edit set image gke.gcr.io/gcs-fuse-csi-driver-webhook=${WEBHOOK_IMAGE}:${STAGINGVERSION};
 	cd ./deploy/overlays/${OVERLAY}; ${BINDIR}/kustomize edit add configmap gcsfusecsi-image-config --behavior=merge --disableNameSuffixHash --from-literal=sidecar-image=${SIDECAR_IMAGE}:${STAGINGVERSION};
+	cd ./deploy/overlays/${OVERLAY}; ${BINDIR}/kustomize edit add configmap gcsfusecsi-image-config --behavior=merge --disableNameSuffixHash --from-literal=metadata-sidecar-image=${PREFETCH_IMAGE}:${STAGINGVERSION};
 	echo "[{\"op\": \"replace\",\"path\": \"/spec/tokenRequests/0/audience\",\"value\": \"${PROJECT}.svc.id.goog\"}]" > ./deploy/overlays/${OVERLAY}/project_patch_csi_driver.json
 	echo "[{\"op\": \"replace\",\"path\": \"/webhooks/0/clientConfig/caBundle\",\"value\": \"${CA_BUNDLE}\"}]" > ./deploy/overlays/${OVERLAY}/caBundle_patch_MutatingWebhookConfiguration.json
 	echo "[{\"op\": \"replace\",\"path\": \"/spec/template/spec/containers/0/env/1/value\",\"value\": \"${IDENTITY_PROVIDER}\"}]" > ./deploy/overlays/${OVERLAY}/identity_provider_patch_csi_node.json

cmd/metadata_prefetch/Dockerfile

@@ -0,0 +1,54 @@
+# Copyright 2018 The Kubernetes Authors.
+# Copyright 2024 Google LLC
+#
+# 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
+#
+#     https://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.
+
+# Build metadata-prefetch go binary
+FROM --platform=$BUILDPLATFORM golang:1.22.7 AS metadata-prefetch-builder
+
+ARG STAGINGVERSION
+
+WORKDIR /gcs-fuse-csi-driver
+ADD . .
+RUN make metadata-prefetch BINDIR=/bin
+
+# go/gke-releasing-policies#base-images
+FROM gke.gcr.io/debian-base:bookworm-v1.0.4-gke.2 AS debian
+
+# go/gke-releasing-policies#base-images
+FROM  gcr.io/distroless/base-debian12 AS output-image
+
+# Copy existing binaries.
+COPY --from=debian /bin/ls /bin/ls
+
+# Copy dependencies.
+COPY --from=debian /lib/x86_64-linux-gnu/libselinux.so.1 /lib/x86_64-linux-gnu/libselinux.so.1
+COPY --from=debian /lib/x86_64-linux-gnu/libc.so.6 /lib/x86_64-linux-gnu/libc.so.6
+COPY --from=debian /lib/x86_64-linux-gnu/libpcre2-8.so.0 /lib/x86_64-linux-gnu/libpcre2-8.so.0
+COPY --from=debian /lib64/ld-linux-x86-64.so.2 /lib64/ld-linux-x86-64.so.2 
+
+# Validate dependencies
+FROM output-image AS validator-image
+COPY --from=debian /bin/bash /bin/bash
+COPY --from=debian /usr/bin/ldd /usr/bin/ldd
+COPY --from=debian /bin/grep /bin/grep
+SHELL ["/bin/bash", "-c"]
+RUN if ldd /bin/ls | grep "not found"; then echo "!!! Missing deps for ls command !!!" && exit 1; fi
+
+# Final image
+FROM output-image
+
+# Copy the built binaries
+COPY --from=metadata-prefetch-builder /bin/gcs-fuse-csi-driver-metadata-prefetch /gcs-fuse-csi-driver-metadata-prefetch
+
+ENTRYPOINT ["/gcs-fuse-csi-driver-metadata-prefetch"]

cmd/metadata_prefetch/main.go

@@ -0,0 +1,102 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+Copyright 2024 Google LLC
+
+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
+
+    https://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 main
+
+import (
+	"context"
+	"flag"
+	"os"
+	"os/exec"
+	"os/signal"
+	"strings"
+	"syscall"
+
+	"k8s.io/klog/v2"
+)
+
+const (
+	mountPathsLocation = "/volumes/"
+)
+
+func main() {
+	klog.InitFlags(nil)
+	flag.Parse()
+
+	// Create cancellable context to pass into exec.
+	ctx, cancel := context.WithCancel(context.Background())
+
+	// Handle SIGTERM signal.
+	sigs := make(chan os.Signal, 1)
+	signal.Notify(sigs, syscall.SIGTERM)
+
+	go func() {
+		<-sigs
+		klog.Info("Caught SIGTERM signal: Terminating...")
+		cancel()
+
+		os.Exit(0) // Exit gracefully
+	}()
+
+	// Start the "ls" command in the background.
+	// All our volumes are mounted under the /volumes/ directory.
+	cmd := exec.CommandContext(ctx, "ls", "-R", mountPathsLocation)
+	cmd.Stdout = nil // Connects file descriptor to the null device (os.DevNull).
+
+	// TODO(hime): We should research stratergies to parallelize ls execution and speed up cache population.
+	err := cmd.Start()
+	if err == nil {
+		mountPaths, err := getDirectoryNames(mountPathsLocation)
+		if err == nil {
+			klog.Infof("Running ls on mountPath(s): %s", strings.Join(mountPaths, ", "))
+		} else {
+			klog.Warningf("failed to get mountPaths: %v", err)
+		}
+
+		err = cmd.Wait()
+		if err != nil {
+			klog.Errorf("Error while executing ls command: %v", err)
+		} else {
+			klog.Info("Metadata prefetch complete")
+		}
+	} else {
+		klog.Errorf("Error starting ls command: %v.", err)
+	}
+
+	klog.Info("Going to sleep...")
+
+	// Keep the process running.
+	select {}
+}
+
+// getDirectoryNames returns a list of strings representing the names of
+// the directories within the provided path.
+func getDirectoryNames(dirPath string) ([]string, error) {
+	directories := []string{}
+	items, err := os.ReadDir(dirPath)
+	if err != nil {
+		return directories, err
+	}
+
+	for _, item := range items {
+		if item.IsDir() {
+			directories = append(directories, item.Name())
+		}
+	}
+
+	return directories, nil
+}

cmd/webhook/main.go

@@ -52,6 +52,7 @@ var (
 	ephemeralStorageRequest = flag.String("sidecar-ephemeral-storage-request", "5Gi", "The default ephemeral storage request for gcsfuse sidecar container.")
 	ephemeralStorageLimit   = flag.String("sidecar-ephemeral-storage-limit", "5Gi", "The default ephemeral storage limit for gcsfuse sidecar container.")
 	sidecarImage            = flag.String("sidecar-image", "", "The gcsfuse sidecar container image.")
+	metadataSidecarImage    = flag.String("metadata-sidecar-image", "", "The metadata prefetch sidecar container image.")
 
 	// These are set at compile time.
 	webhookVersion = "unknown"
@@ -72,7 +73,7 @@ func main() {
 	klog.Infof("Running Google Cloud Storage FUSE CSI driver admission webhook version %v, sidecar container image %v", webhookVersion, *sidecarImage)
 
 	// Load webhook config
-	c := wh.LoadConfig(*sidecarImage, *imagePullPolicy, *cpuRequest, *cpuLimit, *memoryRequest, *memoryLimit, *ephemeralStorageRequest, *ephemeralStorageLimit)
+	c := wh.LoadConfig(*sidecarImage, *metadataSidecarImage, *imagePullPolicy, *cpuRequest, *cpuLimit, *memoryRequest, *memoryLimit, *ephemeralStorageRequest, *ephemeralStorageLimit)
 
 	// Load config for manager, informers, listers
 	kubeConfig := config.GetConfigOrDie()
@@ -103,6 +104,8 @@ func main() {
 	// Setup Informer
 	informerFactory := informers.NewSharedInformerFactory(client, resyncDuration)
 	nodeLister := informerFactory.Core().V1().Nodes().Lister()
+	pvcLister := informerFactory.Core().V1().PersistentVolumeClaims().Lister()
+	pvLister := informerFactory.Core().V1().PersistentVolumes().Lister()
 
 	informerFactory.Start(context.Done())
 	informerFactory.WaitForCacheSync(context.Done())
@@ -140,6 +143,8 @@ func main() {
 			Config:        c,
 			Decoder:       admission.NewDecoder(runtime.NewScheme()),
 			NodeLister:    nodeLister,
+			PvLister:      pvLister,
+			PvcLister:     pvcLister,
 			ServerVersion: serverVersion,
 		},
 	})

deploy/base/node/node.yaml

@@ -133,3 +133,4 @@ metadata:
   name: gcsfusecsi-image-config
 data:
   sidecar-image: gke.gcr.io/gcs-fuse-csi-driver-sidecar-mounter
+  metadata-sidecar-image: gke.gcr.io/gcs-fuse-csi-driver-metadata-prefetch

deploy/base/webhook/deployment.yaml

@@ -54,6 +54,7 @@ spec:
             - --sidecar-ephemeral-storage-limit=0
             - --sidecar-ephemeral-storage-request=5Gi
             - --sidecar-image=$(SIDECAR_IMAGE)
+            - --metadata-sidecar-image=$(METADATA_SIDECAR_IMAGE)
             - --sidecar-image-pull-policy=$(SIDECAR_IMAGE_PULL_POLICY)
             - --cert-dir=/etc/tls-certs
             - --port=22030
@@ -66,6 +67,11 @@ spec:
                 configMapKeyRef:
                   name: gcsfusecsi-image-config
                   key: sidecar-image
+            - name: METADATA_SIDECAR_IMAGE
+              valueFrom:
+                configMapKeyRef:
+                  name: gcsfusecsi-image-config
+                  key: metadata-sidecar-image
           resources:
             limits:
               cpu: 200m

deploy/base/webhook/webhook_setup.yaml

@@ -34,7 +34,7 @@ metadata:
   name: gcs-fuse-csi-webhook-role
 rules:
   - apiGroups: [""]
-    resources: ["nodes"]
+    resources: ["nodes", "persistentvolumes", "persistentvolumeclaims"]
     verbs: ["get","list","watch"]
 ---
 apiVersion: rbac.authorization.k8s.io/v1

pkg/cloud_provider/clientset/fake.go

@@ -46,7 +46,7 @@ func (c *FakeClientset) GetPod(namespace, name string) (*corev1.Pod, error) {
 		Status: corev1.PodStatus{
 			ContainerStatuses: []corev1.ContainerStatus{
 				{
-					Name: webhook.SidecarContainerName,
+					Name: webhook.GcsFuseSidecarName,
 					State: corev1.ContainerState{
 						Running: &corev1.ContainerStateRunning{},
 					},

pkg/csi_driver/utils.go

@@ -313,7 +313,7 @@ func putExitFile(pod *corev1.Pod, targetPath string) error {
 		for _, cs := range pod.Status.ContainerStatuses {
 			switch {
 			// skip the sidecar container itself
-			case cs.Name == webhook.SidecarContainerName:
+			case cs.Name == webhook.GcsFuseSidecarName:
 				continue
 
 			// If the Pod is terminating, the container status from Kubernetes API is not reliable
@@ -453,7 +453,7 @@ func getSidecarContainerStatus(isInitContainer bool, pod *corev1.Pod) (*corev1.C
 	}
 
 	for _, cs := range containerStatusList {
-		if cs.Name == webhook.SidecarContainerName {
+		if cs.Name == webhook.GcsFuseSidecarName {
 			return &cs, nil
 		}
 	}