Fix kubelet PVC metrics using a volume stats collector.

Volumes on each node changes, we should not only add PVC metrics into
gauge vector. It's better use a collector to collector metrics from
stats.

pkg/kubelet/BUILD

@@ -62,6 +62,7 @@ go_library(
         "//pkg/kubelet/kuberuntime:go_default_library",
         "//pkg/kubelet/lifecycle:go_default_library",
         "//pkg/kubelet/metrics:go_default_library",
+        "//pkg/kubelet/metrics/collectors:go_default_library",
         "//pkg/kubelet/mountpod:go_default_library",
         "//pkg/kubelet/network:go_default_library",
         "//pkg/kubelet/network/dns:go_default_library",

pkg/kubelet/kubelet.go

@@ -74,6 +74,7 @@ import (
 	"k8s.io/kubernetes/pkg/kubelet/kuberuntime"
 	"k8s.io/kubernetes/pkg/kubelet/lifecycle"
 	"k8s.io/kubernetes/pkg/kubelet/metrics"
+	"k8s.io/kubernetes/pkg/kubelet/metrics/collectors"
 	"k8s.io/kubernetes/pkg/kubelet/network"
 	"k8s.io/kubernetes/pkg/kubelet/network/dns"
 	"k8s.io/kubernetes/pkg/kubelet/pleg"
@@ -1265,7 +1266,7 @@ func (kl *Kubelet) StartGarbageCollection() {
 // Note that the modules here must not depend on modules that are not initialized here.
 func (kl *Kubelet) initializeModules() error {
 	// Prometheus metrics.
-	metrics.Register(kl.runtimeCache)
+	metrics.Register(kl.runtimeCache, collectors.NewVolumeStatsCollector(kl))
 
 	// Setup filesystem directories.
 	if err := kl.setupDataDirs(); err != nil {

pkg/kubelet/metrics/BUILD

@@ -25,6 +25,9 @@ filegroup(
 
 filegroup(
     name = "all-srcs",
-    srcs = [":package-srcs"],
+    srcs = [
+        ":package-srcs",
+        "//pkg/kubelet/metrics/collectors:all-srcs",
+    ],
     tags = ["automanaged"],
 )

pkg/kubelet/metrics/collectors/BUILD

@@ -0,0 +1,48 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["volume_stats.go"],
+    importpath = "k8s.io/kubernetes/pkg/kubelet/metrics/collectors",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/kubelet/apis/stats/v1alpha1:go_default_library",
+        "//pkg/kubelet/metrics:go_default_library",
+        "//pkg/kubelet/server/stats:go_default_library",
+        "//vendor/github.com/golang/glog:go_default_library",
+        "//vendor/github.com/prometheus/client_golang/prometheus:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "helper_test.go",
+        "volume_stats_test.go",
+    ],
+    embed = [":go_default_library"],
+    importpath = "k8s.io/kubernetes/pkg/kubelet/metrics/collectors",
+    deps = [
+        "//pkg/kubelet/apis/stats/v1alpha1:go_default_library",
+        "//pkg/kubelet/server/stats/testing:go_default_library",
+        "//vendor/github.com/prometheus/client_golang/prometheus:go_default_library",
+        "//vendor/github.com/prometheus/client_model/go:go_default_library",
+        "//vendor/github.com/prometheus/common/expfmt:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

pkg/kubelet/metrics/collectors/helper_test.go

@@ -0,0 +1,182 @@
+/*
+Copyright 2018 The Kubernetes 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.
+*/
+
+// testing helpers copied from k8s.io/kube-state-metrics/collectors/deployment_test.go
+// TODO: share in a public package?
+
+package collectors
+
+import (
+	"bytes"
+	"fmt"
+	"reflect"
+	"sort"
+	"strings"
+
+	"github.com/prometheus/client_golang/prometheus"
+	dto "github.com/prometheus/client_model/go"
+	"github.com/prometheus/common/expfmt"
+)
+
+// gatherAndCompare retrieves all metrics exposed by a collector and compares it
+// to an expected output in the Prometheus text exposition format.
+// metricNames allows only comparing the given metrics. All are compared if it's nil.
+func gatherAndCompare(c prometheus.Collector, expected string, metricNames []string) error {
+	expected = removeUnusedWhitespace(expected)
+
+	reg := prometheus.NewPedanticRegistry()
+	if err := reg.Register(c); err != nil {
+		return fmt.Errorf("registering collector failed: %s", err)
+	}
+	metrics, err := reg.Gather()
+	if err != nil {
+		return fmt.Errorf("gathering metrics failed: %s", err)
+	}
+	if metricNames != nil {
+		metrics = filterMetrics(metrics, metricNames)
+	}
+	var tp expfmt.TextParser
+	expectedMetrics, err := tp.TextToMetricFamilies(bytes.NewReader([]byte(expected)))
+	if err != nil {
+		return fmt.Errorf("parsing expected metrics failed: %s", err)
+	}
+
+	if !reflect.DeepEqual(metrics, normalizeMetricFamilies(expectedMetrics)) {
+		// Encode the gathered output to the readbale text format for comparison.
+		var buf1 bytes.Buffer
+		enc := expfmt.NewEncoder(&buf1, expfmt.FmtText)
+		for _, mf := range metrics {
+			if err := enc.Encode(mf); err != nil {
+				return fmt.Errorf("encoding result failed: %s", err)
+			}
+		}
+		// Encode normalized expected metrics again to generate them in the same ordering
+		// the registry does to spot differences more easily.
+		var buf2 bytes.Buffer
+		enc = expfmt.NewEncoder(&buf2, expfmt.FmtText)
+		for _, mf := range normalizeMetricFamilies(expectedMetrics) {
+			if err := enc.Encode(mf); err != nil {
+				return fmt.Errorf("encoding result failed: %s", err)
+			}
+		}
+
+		return fmt.Errorf(`metric output does not match expectation; want:
+%s
+
+got:
+
+%s`, buf2.String(), buf1.String())
+	}
+	return nil
+}
+
+func filterMetrics(metrics []*dto.MetricFamily, names []string) []*dto.MetricFamily {
+	var filtered []*dto.MetricFamily
+	for _, m := range metrics {
+		drop := true
+		for _, name := range names {
+			if m.GetName() == name {
+				drop = false
+				break
+			}
+		}
+		if !drop {
+			filtered = append(filtered, m)
+		}
+	}
+	return filtered
+}
+
+func removeUnusedWhitespace(s string) string {
+	var (
+		trimmedLine  string
+		trimmedLines []string
+		lines        = strings.Split(s, "\n")
+	)
+
+	for _, l := range lines {
+		trimmedLine = strings.TrimSpace(l)
+
+		if len(trimmedLine) > 0 {
+			trimmedLines = append(trimmedLines, trimmedLine)
+		}
+	}
+
+	// The Prometheus metrics representation parser expects an empty line at the
+	// end otherwise fails with an unexpected EOF error.
+	return strings.Join(trimmedLines, "\n") + "\n"
+}
+
+// The below sorting code is copied form the Prometheus client library modulo the added
+// label pair sorting.
+// https://github.com/prometheus/client_golang/blob/ea6e1db4cb8127eeb0b6954f7320363e5451820f/prometheus/registry.go#L642-L684
+
+// metricSorter is a sortable slice of *dto.Metric.
+type metricSorter []*dto.Metric
+
+func (s metricSorter) Len() int {
+	return len(s)
+}
+
+func (s metricSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s metricSorter) Less(i, j int) bool {
+	sort.Sort(prometheus.LabelPairSorter(s[i].Label))
+	sort.Sort(prometheus.LabelPairSorter(s[j].Label))
+
+	if len(s[i].Label) != len(s[j].Label) {
+		return len(s[i].Label) < len(s[j].Label)
+	}
+
+	for n, lp := range s[i].Label {
+		vi := lp.GetValue()
+		vj := s[j].Label[n].GetValue()
+		if vi != vj {
+			return vi < vj
+		}
+	}
+
+	if s[i].TimestampMs == nil {
+		return false
+	}
+	if s[j].TimestampMs == nil {
+		return true
+	}
+	return s[i].GetTimestampMs() < s[j].GetTimestampMs()
+}
+
+// normalizeMetricFamilies returns a MetricFamily slice with empty
+// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
+// the slice, with the contained Metrics sorted within each MetricFamily.
+func normalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
+	for _, mf := range metricFamiliesByName {
+		sort.Sort(metricSorter(mf.Metric))
+	}
+	names := make([]string, 0, len(metricFamiliesByName))
+	for name, mf := range metricFamiliesByName {
+		if len(mf.Metric) > 0 {
+			names = append(names, name)
+		}
+	}
+	sort.Strings(names)
+	result := make([]*dto.MetricFamily, 0, len(names))
+	for _, name := range names {
+		result = append(result, metricFamiliesByName[name])
+	}
+	return result
+}

pkg/kubelet/metrics/collectors/volume_stats.go

@@ -0,0 +1,120 @@
+/*
+Copyright 2018 The Kubernetes 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 collectors
+
+import (
+	"github.com/golang/glog"
+	"github.com/prometheus/client_golang/prometheus"
+	"k8s.io/apimachinery/pkg/util/sets"
+	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
+	"k8s.io/kubernetes/pkg/kubelet/metrics"
+	serverstats "k8s.io/kubernetes/pkg/kubelet/server/stats"
+)
+
+var (
+	volumeStatsCapacityBytesDesc = prometheus.NewDesc(
+		prometheus.BuildFQName("", metrics.KubeletSubsystem, metrics.VolumeStatsCapacityBytesKey),
+		"Capacity in bytes of the volume",
+		[]string{"namespace", "persistentvolumeclaim"}, nil,
+	)
+	volumeStatsAvailableBytesDesc = prometheus.NewDesc(
+		prometheus.BuildFQName("", metrics.KubeletSubsystem, metrics.VolumeStatsAvailableBytesKey),
+		"Number of available bytes in the volume",
+		[]string{"namespace", "persistentvolumeclaim"}, nil,
+	)
+	volumeStatsUsedBytesDesc = prometheus.NewDesc(
+		prometheus.BuildFQName("", metrics.KubeletSubsystem, metrics.VolumeStatsUsedBytesKey),
+		"Number of used bytes in the volume",
+		[]string{"namespace", "persistentvolumeclaim"}, nil,
+	)
+	volumeStatsInodesDesc = prometheus.NewDesc(
+		prometheus.BuildFQName("", metrics.KubeletSubsystem, metrics.VolumeStatsInodesKey),
+		"Maximum number of inodes in the volume",
+		[]string{"namespace", "persistentvolumeclaim"}, nil,
+	)
+	volumeStatsInodesFreeDesc = prometheus.NewDesc(
+		prometheus.BuildFQName("", metrics.KubeletSubsystem, metrics.VolumeStatsInodesFreeKey),
+		"Number of free inodes in the volume",
+		[]string{"namespace", "persistentvolumeclaim"}, nil,
+	)
+	volumeStatsInodesUsedDesc = prometheus.NewDesc(
+		prometheus.BuildFQName("", metrics.KubeletSubsystem, metrics.VolumeStatsInodesUsedKey),
+		"Number of used inodes in the volume",
+		[]string{"namespace", "persistentvolumeclaim"}, nil,
+	)
+)
+
+type volumeStatsCollecotr struct {
+	statsProvider serverstats.StatsProvider
+}
+
+// NewVolumeStatsCollector creates a volume stats prometheus collector.
+func NewVolumeStatsCollector(statsProvider serverstats.StatsProvider) prometheus.Collector {
+	return &volumeStatsCollecotr{statsProvider: statsProvider}
+}
+
+// Describe implements the prometheus.Collector interface.
+func (collector *volumeStatsCollecotr) Describe(ch chan<- *prometheus.Desc) {
+	ch <- volumeStatsCapacityBytesDesc
+	ch <- volumeStatsAvailableBytesDesc
+	ch <- volumeStatsUsedBytesDesc
+	ch <- volumeStatsInodesDesc
+	ch <- volumeStatsInodesFreeDesc
+	ch <- volumeStatsInodesUsedDesc
+}
+
+// Collect implements the prometheus.Collector interface.
+func (collector *volumeStatsCollecotr) Collect(ch chan<- prometheus.Metric) {
+	podStats, err := collector.statsProvider.ListPodStats()
+	if err != nil {
+		return
+	}
+	addGauge := func(desc *prometheus.Desc, pvcRef *stats.PVCReference, v float64, lv ...string) {
+		lv = append([]string{pvcRef.Namespace, pvcRef.Name}, lv...)
+		metric, err := prometheus.NewConstMetric(desc, prometheus.GaugeValue, v, lv...)
+		if err != nil {
+			glog.Warningf("Failed to generate metric: %v", err)
+			return
+		}
+		ch <- metric
+	}
+	allPVCs := sets.String{}
+	for _, podStat := range podStats {
+		if podStat.VolumeStats == nil {
+			continue
+		}
+		for _, volumeStat := range podStat.VolumeStats {
+			pvcRef := volumeStat.PVCRef
+			if pvcRef == nil {
+				// ignore if no PVC reference
+				continue
+			}
+			pvcUniqStr := pvcRef.Namespace + "/" + pvcRef.Name
+			if allPVCs.Has(pvcUniqStr) {
+				// ignore if already collected
+				continue
+			}
+			addGauge(volumeStatsCapacityBytesDesc, pvcRef, float64(*volumeStat.CapacityBytes))
+			addGauge(volumeStatsAvailableBytesDesc, pvcRef, float64(*volumeStat.AvailableBytes))
+			addGauge(volumeStatsUsedBytesDesc, pvcRef, float64(*volumeStat.UsedBytes))
+			addGauge(volumeStatsInodesDesc, pvcRef, float64(*volumeStat.Inodes))
+			addGauge(volumeStatsInodesFreeDesc, pvcRef, float64(*volumeStat.InodesFree))
+			addGauge(volumeStatsInodesUsedDesc, pvcRef, float64(*volumeStat.InodesUsed))
+			allPVCs.Insert(pvcUniqStr)
+		}
+	}
+}

pkg/kubelet/metrics/collectors/volume_stats_test.go

@@ -0,0 +1,135 @@
+/*
+Copyright 2018 The Kubernetes 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 collectors
+
+import (
+	"testing"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	statsapi "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
+	statstest "k8s.io/kubernetes/pkg/kubelet/server/stats/testing"
+)
+
+func newUint64Pointer(i uint64) *uint64 {
+	return &i
+}
+
+func TestVolumeStatsCollector(t *testing.T) {
+	// Fixed metadata on type and help text. We prepend this to every expected
+	// output so we only have to modify a single place when doing adjustments.
+	const metadata = `
+		# HELP kubelet_volume_stats_available_bytes Number of available bytes in the volume
+		# TYPE kubelet_volume_stats_available_bytes gauge
+		# HELP kubelet_volume_stats_capacity_bytes Capacity in bytes of the volume
+		# TYPE kubelet_volume_stats_capacity_bytes gauge
+		# HELP kubelet_volume_stats_inodes Maximum number of inodes in the volume
+		# TYPE kubelet_volume_stats_inodes gauge
+		# HELP kubelet_volume_stats_inodes_free Number of free inodes in the volume
+		# TYPE kubelet_volume_stats_inodes_free gauge
+		# HELP kubelet_volume_stats_inodes_used Number of used inodes in the volume
+		# TYPE kubelet_volume_stats_inodes_used gauge
+		# HELP kubelet_volume_stats_used_bytes Number of used bytes in the volume
+		# TYPE kubelet_volume_stats_used_bytes gauge
+	`
+
+	var (
+		podStats = []statsapi.PodStats{
+			{
+				PodRef:    statsapi.PodReference{Name: "test-pod", Namespace: "test-namespace", UID: "UID_test-pod"},
+				StartTime: metav1.Now(),
+				VolumeStats: []statsapi.VolumeStats{
+					{
+						FsStats: statsapi.FsStats{
+							Time:           metav1.Now(),
+							AvailableBytes: newUint64Pointer(5.663154176e+09),
+							CapacityBytes:  newUint64Pointer(1.0434699264e+10),
+							UsedBytes:      newUint64Pointer(4.21789696e+09),
+							InodesFree:     newUint64Pointer(655344),
+							Inodes:         newUint64Pointer(655360),
+							InodesUsed:     newUint64Pointer(16),
+						},
+						Name:   "test",
+						PVCRef: nil,
+					},
+					{
+						FsStats: statsapi.FsStats{
+							Time:           metav1.Now(),
+							AvailableBytes: newUint64Pointer(5.663154176e+09),
+							CapacityBytes:  newUint64Pointer(1.0434699264e+10),
+							UsedBytes:      newUint64Pointer(4.21789696e+09),
+							InodesFree:     newUint64Pointer(655344),
+							Inodes:         newUint64Pointer(655360),
+							InodesUsed:     newUint64Pointer(16),
+						},
+						Name: "test",
+						PVCRef: &statsapi.PVCReference{
+							Name:      "testpvc",
+							Namespace: "testns",
+						},
+					},
+				},
+			},
+			{
+				// Another pod references the same PVC (test-namespace/testpvc).
+				PodRef:    statsapi.PodReference{Name: "test-pod-2", Namespace: "test-namespace", UID: "UID_test-pod"},
+				StartTime: metav1.Now(),
+				VolumeStats: []statsapi.VolumeStats{
+					{
+						FsStats: statsapi.FsStats{
+							Time:           metav1.Now(),
+							AvailableBytes: newUint64Pointer(5.663154176e+09),
+							CapacityBytes:  newUint64Pointer(1.0434699264e+10),
+							UsedBytes:      newUint64Pointer(4.21789696e+09),
+							InodesFree:     newUint64Pointer(655344),
+							Inodes:         newUint64Pointer(655360),
+							InodesUsed:     newUint64Pointer(16),
+						},
+						Name: "test",
+						PVCRef: &statsapi.PVCReference{
+							Name:      "testpvc",
+							Namespace: "testns",
+						},
+					},
+				},
+			},
+		}
+
+		want = metadata + `
+			kubelet_volume_stats_available_bytes{namespace="testns",persistentvolumeclaim="testpvc"} 5.663154176e+09
+			kubelet_volume_stats_capacity_bytes{namespace="testns",persistentvolumeclaim="testpvc"} 1.0434699264e+10
+			kubelet_volume_stats_inodes{namespace="testns",persistentvolumeclaim="testpvc"} 655360
+			kubelet_volume_stats_inodes_free{namespace="testns",persistentvolumeclaim="testpvc"} 655344
+			kubelet_volume_stats_inodes_used{namespace="testns",persistentvolumeclaim="testpvc"} 16
+			kubelet_volume_stats_used_bytes{namespace="testns",persistentvolumeclaim="testpvc"} 4.21789696e+09
+			`
+
+		metrics = []string{
+			"kubelet_volume_stats_available_bytes",
+			"kubelet_volume_stats_capacity_bytes",
+			"kubelet_volume_stats_inodes",
+			"kubelet_volume_stats_inodes_free",
+			"kubelet_volume_stats_inodes_used",
+			"kubelet_volume_stats_used_bytes",
+		}
+	)
+
+	mockStatsProvider := new(statstest.StatsProvider)
+	mockStatsProvider.On("ListPodStats").Return(podStats, nil)
+	if err := gatherAndCompare(&volumeStatsCollecotr{statsProvider: mockStatsProvider}, want, metrics); err != nil {
+		t.Errorf("unexpected collecting result:\n%s", err)
+	}
+}

pkg/kubelet/metrics/metrics.go

@@ -134,54 +134,6 @@ var (
 		},
 		[]string{"eviction_signal"},
 	)
-	VolumeStatsCapacityBytes = prometheus.NewGaugeVec(
-		prometheus.GaugeOpts{
-			Subsystem: KubeletSubsystem,
-			Name:      VolumeStatsCapacityBytesKey,
-			Help:      "Capacity in bytes of the volume",
-		},
-		[]string{"namespace", "persistentvolumeclaim"},
-	)
-	VolumeStatsAvailableBytes = prometheus.NewGaugeVec(
-		prometheus.GaugeOpts{
-			Subsystem: KubeletSubsystem,
-			Name:      VolumeStatsAvailableBytesKey,
-			Help:      "Number of available bytes in the volume",
-		},
-		[]string{"namespace", "persistentvolumeclaim"},
-	)
-	VolumeStatsUsedBytes = prometheus.NewGaugeVec(
-		prometheus.GaugeOpts{
-			Subsystem: KubeletSubsystem,
-			Name:      VolumeStatsUsedBytesKey,
-			Help:      "Number of used bytes in the volume",
-		},
-		[]string{"namespace", "persistentvolumeclaim"},
-	)
-	VolumeStatsInodes = prometheus.NewGaugeVec(
-		prometheus.GaugeOpts{
-			Subsystem: KubeletSubsystem,
-			Name:      VolumeStatsInodesKey,
-			Help:      "Maximum number of inodes in the volume",
-		},
-		[]string{"namespace", "persistentvolumeclaim"},
-	)
-	VolumeStatsInodesFree = prometheus.NewGaugeVec(
-		prometheus.GaugeOpts{
-			Subsystem: KubeletSubsystem,
-			Name:      VolumeStatsInodesFreeKey,
-			Help:      "Number of free inodes in the volume",
-		},
-		[]string{"namespace", "persistentvolumeclaim"},
-	)
-	VolumeStatsInodesUsed = prometheus.NewGaugeVec(
-		prometheus.GaugeOpts{
-			Subsystem: KubeletSubsystem,
-			Name:      VolumeStatsInodesUsedKey,
-			Help:      "Number of used inodes in the volume",
-		},
-		[]string{"namespace", "persistentvolumeclaim"},
-	)
 	DevicePluginRegistrationCount = prometheus.NewCounterVec(
 		prometheus.CounterOpts{
 			Subsystem: KubeletSubsystem,
@@ -203,7 +155,7 @@ var (
 var registerMetrics sync.Once
 
 // Register all metrics.
-func Register(containerCache kubecontainer.RuntimeCache) {
+func Register(containerCache kubecontainer.RuntimeCache, collectors ...prometheus.Collector) {
 	// Register the metrics.
 	registerMetrics.Do(func() {
 		prometheus.MustRegister(PodWorkerLatency)
@@ -218,14 +170,11 @@ func Register(containerCache kubecontainer.RuntimeCache) {
 		prometheus.MustRegister(RuntimeOperationsLatency)
 		prometheus.MustRegister(RuntimeOperationsErrors)
 		prometheus.MustRegister(EvictionStatsAge)
-		prometheus.MustRegister(VolumeStatsCapacityBytes)
-		prometheus.MustRegister(VolumeStatsAvailableBytes)
-		prometheus.MustRegister(VolumeStatsUsedBytes)
-		prometheus.MustRegister(VolumeStatsInodes)
-		prometheus.MustRegister(VolumeStatsInodesFree)
-		prometheus.MustRegister(VolumeStatsInodesUsed)
 		prometheus.MustRegister(DevicePluginRegistrationCount)
 		prometheus.MustRegister(DevicePluginAllocationLatency)
+		for _, collector := range collectors {
+			prometheus.MustRegister(collector)
+		}
 	})
 }
 

pkg/kubelet/server/stats/BUILD

@@ -16,7 +16,6 @@ go_library(
         "//pkg/kubelet/apis/stats/v1alpha1:go_default_library",
         "//pkg/kubelet/cm:go_default_library",
         "//pkg/kubelet/container:go_default_library",
-        "//pkg/kubelet/metrics:go_default_library",
         "//pkg/kubelet/util/format:go_default_library",
         "//pkg/volume:go_default_library",
         "//vendor/github.com/emicklei/go-restful:go_default_library",

pkg/kubelet/server/stats/volume_stat_calculator.go

@@ -24,7 +24,6 @@ import (
 	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/wait"
 	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
-	"k8s.io/kubernetes/pkg/kubelet/metrics"
 	"k8s.io/kubernetes/pkg/kubelet/util/format"
 	"k8s.io/kubernetes/pkg/volume"
 
@@ -122,8 +121,6 @@ func (s *volumeStatCalculator) calcAndStoreStats() {
 				Name:      pvcSource.ClaimName,
 				Namespace: s.pod.GetNamespace(),
 			}
-			// Set the PVC's prometheus metrics
-			s.setPVCMetrics(pvcRef, metric)
 		}
 		volumeStats := s.parsePodVolumeStats(name, pvcRef, metric, volSpec)
 		if isVolumeEphemeral(volSpec) {
@@ -163,13 +160,3 @@ func isVolumeEphemeral(volume v1.Volume) bool {
 	}
 	return false
 }
-
-// setPVCMetrics sets the given PVC's prometheus metrics to match the given volume.Metrics
-func (s *volumeStatCalculator) setPVCMetrics(pvcRef *stats.PVCReference, metric *volume.Metrics) {
-	metrics.VolumeStatsAvailableBytes.WithLabelValues(pvcRef.Namespace, pvcRef.Name).Set(float64(metric.Available.Value()))
-	metrics.VolumeStatsCapacityBytes.WithLabelValues(pvcRef.Namespace, pvcRef.Name).Set(float64(metric.Capacity.Value()))
-	metrics.VolumeStatsUsedBytes.WithLabelValues(pvcRef.Namespace, pvcRef.Name).Set(float64(metric.Used.Value()))
-	metrics.VolumeStatsInodes.WithLabelValues(pvcRef.Namespace, pvcRef.Name).Set(float64(metric.Inodes.Value()))
-	metrics.VolumeStatsInodesFree.WithLabelValues(pvcRef.Namespace, pvcRef.Name).Set(float64(metric.InodesFree.Value()))
-	metrics.VolumeStatsInodesUsed.WithLabelValues(pvcRef.Namespace, pvcRef.Name).Set(float64(metric.InodesUsed.Value()))
-}