Expose NVMe Volume Metrics

Makefile

@@ -129,7 +129,7 @@ e2e/single-az: bin/helm bin/ginkgo
 	TEST_PATH=./tests/e2e/... \
 	GINKGO_FOCUS="\[ebs-csi-e2e\] \[single-az\]" \
 	GINKGO_PARALLEL=5 \
-	HELM_EXTRA_FLAGS="--set=controller.volumeModificationFeature.enabled=true,sidecars.provisioner.additionalArgs[0]='--feature-gates=VolumeAttributesClass=true',sidecars.resizer.additionalArgs[0]='--feature-gates=VolumeAttributesClass=true'" \
+	HELM_EXTRA_FLAGS="--set=controller.volumeModificationFeature.enabled=true,sidecars.provisioner.additionalArgs[0]='--feature-gates=VolumeAttributesClass=true',sidecars.resizer.additionalArgs[0]='--feature-gates=VolumeAttributesClass=true',node.enableMetrics=true" \
 	./hack/e2e/run.sh
 
 .PHONY: e2e/multi-az

charts/aws-ebs-csi-driver/templates/_node.tpl

@@ -70,6 +70,12 @@ spec:
             {{- with .Values.node.reservedVolumeAttachments }}
             - --reserved-volume-attachments={{ . }}
             {{- end }}
+            {{- if .Values.node.enableMetrics }}
+            - --http-endpoint=0.0.0.0:3302
+            {{- end}}
+            {{- with .Values.node.kubeletPath }}
+            - --csi-mount-point-prefix={{ . }}
+            {{- end}}
             {{- with .Values.node.volumeAttachLimit }}
             - --volume-attach-limit={{ . }}
             {{- end }}

charts/aws-ebs-csi-driver/templates/metrics.yaml

@@ -40,3 +40,21 @@ spec:
       interval: {{ .Values.controller.serviceMonitor.interval | default "15s"}}
 {{- end }}
 {{- end }}
+---
+{{- if .Values.node.enableMetrics -}}
+apiVersion: v1
+kind: Service
+metadata:
+  name: ebs-csi-node
+  namespace: {{ .Release.Namespace }}
+  labels:
+    app: ebs-csi-node
+spec:
+  selector:
+    app: ebs-csi-node
+  ports:
+    - name: metrics
+      port: 3302
+      targetPort: 3302
+  type: ClusterIP
+{{- end }}

cmd/main.go

@@ -134,11 +134,6 @@ func main() {
 		}()
 	}
 
-	if options.HTTPEndpoint != "" {
-		r := metrics.InitializeRecorder()
-		r.InitializeMetricsHandler(options.HTTPEndpoint, "/metrics", options.MetricsCertFile, options.MetricsKeyFile)
-	}
-
 	cfg := metadata.MetadataServiceConfig{
 		EC2MetadataClient: metadata.DefaultEC2MetadataClient,
 		K8sAPIClient:      metadata.DefaultKubernetesAPIClient(options.Kubeconfig),
@@ -159,6 +154,15 @@ func main() {
 		md, metadataErr = metadata.NewMetadataService(cfg, region)
 	}
 
+	if options.HTTPEndpoint != "" {
+		r := metrics.InitializeRecorder()
+		r.InitializeMetricsHandler(options.HTTPEndpoint, "/metrics", options.MetricsCertFile, options.MetricsKeyFile)
+
+		if options.Mode == driver.NodeMode || options.Mode == driver.AllMode {
+			metrics.InitializeNVME(r, options.CsiMountPointPath, md.GetInstanceID())
+		}
+	}
+
 	if metadataErr != nil {
 		klog.ErrorS(metadataErr, "Failed to initialize metadata when it is required")
 		if options.Mode == driver.ControllerMode {

deploy/kubernetes/base/node.yaml

@@ -59,6 +59,7 @@ spec:
           args:
             - node
             - --endpoint=$(CSI_ENDPOINT)
+            - --csi-mount-point-prefix=/var/lib/kubelet
             - --logging-format=text
             - --v=2
           env:

go.mod

@@ -16,6 +16,7 @@ require (
 	github.com/kubernetes-csi/external-snapshotter/client/v4 v4.2.0
 	github.com/onsi/ginkgo/v2 v2.21.0
 	github.com/onsi/gomega v1.35.0
+	github.com/prometheus/client_golang v1.20.5
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.9.0
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.56.0
@@ -99,7 +100,6 @@ require (
 	github.com/opencontainers/selinux v1.11.1 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
-	github.com/prometheus/client_golang v1.20.5 // indirect
 	github.com/prometheus/client_model v0.6.1 // indirect
 	github.com/prometheus/common v0.60.1 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect

pkg/driver/node.go

@@ -648,6 +648,9 @@ func (d *NodeService) nodePublishVolumeForBlock(req *csi.NodePublishVolumeReques
 	}
 
 	// Create the mount point as a file since bind mount device node requires it to be a file
+	// This implementation detail is relied upon by the NVMECollector,
+	// which discovers block devices by parsing /proc/self/mountinfo. The bind mount
+	// created here ensures block devices appear in mountinfo even without a filesystem.
 	klog.V(4).InfoS("NodePublishVolume [block]: making target file", "target", target)
 	if err = d.mounter.MakeFile(target); err != nil {
 		if removeErr := os.Remove(target); removeErr != nil {

pkg/driver/options.go

@@ -89,6 +89,8 @@ type Options struct {
 	WindowsHostProcess bool
 	// LegacyXFSProgs formats XFS volumes with `bigtime=0,inobtcount=0,reflink=0`, so that they can be mounted onto nodes with linux kernel ≤ v5.4. Volumes formatted with this option may experience issues after 2038, and will be unable to use some XFS features (for example, reflinks).
 	LegacyXFSProgs bool
+	// CsiMountPointPath is the path where CSI volumes are expected to be mounted on the node.
+	CsiMountPointPath string
 }
 
 func (o *Options) AddFlags(f *flag.FlagSet) {
@@ -118,6 +120,7 @@ func (o *Options) AddFlags(f *flag.FlagSet) {
 		f.IntVar(&o.ReservedVolumeAttachments, "reserved-volume-attachments", -1, "Number of volume attachments reserved for system use. Not used when --volume-attach-limit is specified. The total amount of volume attachments for a node is computed as: <nr. of attachments for corresponding instance type> - <number of NICs, if relevant to the instance type> - <reserved-volume-attachments value>. When -1, the amount of reserved attachments is loaded from instance metadata that captured state at node boot and may include not only system disks but also CSI volumes.")
 		f.BoolVar(&o.WindowsHostProcess, "windows-host-process", false, "ALPHA: Indicates whether the driver is running in a Windows privileged container")
 		f.BoolVar(&o.LegacyXFSProgs, "legacy-xfs", false, "Warning: This option will be removed in a future version of EBS CSI Driver. Formats XFS volumes with `bigtime=0,inobtcount=0,reflink=0`, so that they can be mounted onto nodes with linux kernel ≤ v5.4. Volumes formatted with this option may experience issues after 2038, and will be unable to use some XFS features (for example, reflinks).")
+		f.StringVar(&o.CsiMountPointPath, "csi-mount-point-prefix", "", "A prefix of the mountpoints of all CSI-managed volumes. If this value is non-empty, all volumes mounted to a path beginning with the provided value are assumed to be CSI volumes owned by the EBS CSI Driver and safe to treat as such (for example, by exposing volume metrics).")
 	}
 }
 

pkg/driver/options_test.go

@@ -74,6 +74,10 @@ func TestAddFlags(t *testing.T) {
 		t.Errorf("error setting legacy-xfs: %v", err)
 	}
 
+	if err := f.Set("csi-mount-point-prefix", "/var/lib/kubelet"); err != nil {
+		t.Errorf("error setting csi-mount-point-prefix: %v", err)
+	}
+
 	if o.Endpoint != "custom-endpoint" {
 		t.Errorf("unexpected Endpoint: got %s, want custom-endpoint", o.Endpoint)
 	}

pkg/metrics/metrics.go

@@ -19,7 +19,8 @@ import (
 	"sync"
 	"time"
 
-	"k8s.io/component-base/metrics"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"k8s.io/klog/v2"
 )
 
@@ -29,7 +30,7 @@ var (
 )
 
 type metricRecorder struct {
-	registry metrics.KubeRegistry
+	registry *prometheus.Registry
 	metrics  map[string]interface{}
 }
 
@@ -43,13 +44,18 @@ func Recorder() *metricRecorder {
 func InitializeRecorder() *metricRecorder {
 	once.Do(func() {
 		r = &metricRecorder{
-			registry: metrics.NewKubeRegistry(),
+			registry: prometheus.NewRegistry(),
 			metrics:  make(map[string]interface{}),
 		}
 	})
 	return r
 }
 
+// InitializeNVME registers the NVMe collector for gathering metrics from NVMe devices.
+func InitializeNVME(r *metricRecorder, csiMountPointPath, instanceID string) {
+	registerNVMECollector(r, csiMountPointPath, instanceID)
+}
+
 // IncreaseCount increases the counter metric by 1.
 func (m *metricRecorder) IncreaseCount(name string, labels map[string]string) {
 	if m == nil {
@@ -65,7 +71,7 @@ func (m *metricRecorder) IncreaseCount(name string, labels map[string]string) {
 		return
 	}
 
-	metricAsCounterVec, ok := metric.(*metrics.CounterVec)
+	metricAsCounterVec, ok := metric.(*prometheus.CounterVec)
 	if ok {
 		metricAsCounterVec.With(labels).Inc()
 	} else {
@@ -87,7 +93,7 @@ func (m *metricRecorder) ObserveHistogram(name string, value float64, labels map
 		return
 	}
 
-	metricAsHistogramVec, ok := metric.(*metrics.HistogramVec)
+	metricAsHistogramVec, ok := metric.(*prometheus.HistogramVec)
 	if ok {
 		metricAsHistogramVec.With(labels).Observe(value)
 	} else {
@@ -103,11 +109,7 @@ func (m *metricRecorder) InitializeMetricsHandler(address, path, certFile, keyFi
 	}
 
 	mux := http.NewServeMux()
-	mux.Handle(path, metrics.HandlerFor(
-		m.registry,
-		metrics.HandlerOpts{
-			ErrorHandling: metrics.ContinueOnError,
-		}))
+	mux.Handle(path, promhttp.HandlerFor(m.registry, promhttp.HandlerOpts{ErrorHandling: promhttp.ContinueOnError}))
 
 	server := &http.Server{
 		Addr:        address,
@@ -136,7 +138,14 @@ func (m *metricRecorder) registerHistogramVec(name, help string, labels []string
 	if _, exists := m.metrics[name]; exists {
 		return
 	}
-	histogram := createHistogramVec(name, help, labels, buckets)
+	histogram := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    name,
+			Help:    help,
+			Buckets: buckets,
+		},
+		labels,
+	)
 	m.metrics[name] = histogram
 	m.registry.MustRegister(histogram)
 }
@@ -145,30 +154,15 @@ func (m *metricRecorder) registerCounterVec(name, help string, labels []string)
 	if _, exists := m.metrics[name]; exists {
 		return
 	}
-	counter := createCounterVec(name, help, labels)
-	m.metrics[name] = counter
-	m.registry.MustRegister(counter)
-}
-
-func createHistogramVec(name, help string, labels []string, buckets []float64) *metrics.HistogramVec {
-	opts := &metrics.HistogramOpts{
-		Name:           name,
-		Help:           help,
-		StabilityLevel: metrics.ALPHA,
-		Buckets:        buckets,
-	}
-	return metrics.NewHistogramVec(opts, labels)
-}
-
-func createCounterVec(name, help string, labels []string) *metrics.CounterVec {
-	return metrics.NewCounterVec(
-		&metrics.CounterOpts{
-			Name:           name,
-			Help:           help,
-			StabilityLevel: metrics.ALPHA,
+	counter := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: name,
+			Help: help,
 		},
 		labels,
 	)
+	m.metrics[name] = counter
+	m.registry.MustRegister(counter)
 }
 
 func getLabelNames(labels map[string]string) []string {

pkg/metrics/metrics_test.go

@@ -34,7 +34,7 @@ func TestMetricRecorder(t *testing.T) {
 				m.IncreaseCount("test_total", map[string]string{"key": "value"})
 			},
 			expected: `
-# HELP test_total [ALPHA] ebs_csi_aws_com metric
+# HELP test_total ebs_csi_aws_com metric
 # TYPE test_total counter
 test_total{key="value"} 1
 			`,
@@ -46,7 +46,7 @@ test_total{key="value"} 1
 				m.ObserveHistogram("test", 1.5, map[string]string{"key": "value"}, []float64{1, 2, 3})
 			},
 			expected: `
-# HELP test [ALPHA] ebs_csi_aws_com metric
+# HELP test ebs_csi_aws_com metric
 # TYPE test histogram
 test{key="value",le="1"} 0
 test{key="value",le="2"} 1
@@ -66,7 +66,7 @@ test_count{key="value"} 1
 				m.IncreaseCount("test_re_register_total", map[string]string{"key": "value2"})
 			},
 			expected: `
-# HELP test_re_register_total [ALPHA] ebs_csi_aws_com metric
+# HELP test_re_register_total ebs_csi_aws_com metric
 # TYPE test_re_register_total counter
 test_re_register_total{key="value1"} 2
 test_re_register_total{key="value2"} 1