Merge pull request #64527 from gnufied/add-pvc-in-use-metrics

Automatic merge from submit-queue (batch tested with PRs 65361, 64527). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Add attachable pvc in use metrics

This metric reports number of PVCs that are in-use in Kubernetes with plugin and node name as dimensions. 

This allows us to figure out, how many PVCs each node is using. It is super helpful in figuring out attach/detach issues.

/sig storage

cc @jsafrane @tsmetana @msau42 

```release-note
Add metrics for PVC in-use
```

pkg/controller/volume/attachdetach/BUILD

@@ -14,6 +14,7 @@ go_library(
         "//pkg/cloudprovider:go_default_library",
         "//pkg/controller:go_default_library",
         "//pkg/controller/volume/attachdetach/cache:go_default_library",
+        "//pkg/controller/volume/attachdetach/metrics:go_default_library",
         "//pkg/controller/volume/attachdetach/populator:go_default_library",
         "//pkg/controller/volume/attachdetach/reconciler:go_default_library",
         "//pkg/controller/volume/attachdetach/statusupdater:go_default_library",
@@ -69,6 +70,7 @@ filegroup(
     srcs = [
         ":package-srcs",
         "//pkg/controller/volume/attachdetach/cache:all-srcs",
+        "//pkg/controller/volume/attachdetach/metrics:all-srcs",
         "//pkg/controller/volume/attachdetach/populator:all-srcs",
         "//pkg/controller/volume/attachdetach/reconciler:all-srcs",
         "//pkg/controller/volume/attachdetach/statusupdater:all-srcs",

pkg/controller/volume/attachdetach/attach_detach_controller.go

@@ -39,6 +39,7 @@ import (
 	"k8s.io/kubernetes/pkg/cloudprovider"
 	"k8s.io/kubernetes/pkg/controller"
 	"k8s.io/kubernetes/pkg/controller/volume/attachdetach/cache"
+	"k8s.io/kubernetes/pkg/controller/volume/attachdetach/metrics"
 	"k8s.io/kubernetes/pkg/controller/volume/attachdetach/populator"
 	"k8s.io/kubernetes/pkg/controller/volume/attachdetach/reconciler"
 	"k8s.io/kubernetes/pkg/controller/volume/attachdetach/statusupdater"
@@ -273,6 +274,7 @@ func (adc *attachDetachController) Run(stopCh <-chan struct{}) {
 	}
 	go adc.reconciler.Run(stopCh)
 	go adc.desiredStateOfWorldPopulator.Run(stopCh)
+	metrics.Register(adc.pvcLister, adc.pvLister, adc.podLister, &adc.volumePluginMgr)
 
 	<-stopCh
 }

pkg/controller/volume/attachdetach/metrics/BUILD

@@ -0,0 +1,46 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["metrics.go"],
+    importpath = "k8s.io/kubernetes/pkg/controller/volume/attachdetach/metrics",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/controller/volume/attachdetach/util:go_default_library",
+        "//pkg/volume:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/labels:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/types:go_default_library",
+        "//staging/src/k8s.io/client-go/listers/core/v1:go_default_library",
+        "//vendor/github.com/golang/glog:go_default_library",
+        "//vendor/github.com/prometheus/client_golang/prometheus:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["metrics_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//pkg/controller:go_default_library",
+        "//pkg/volume/testing:go_default_library",
+        "//staging/src/k8s.io/api/core/v1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/api/resource:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//staging/src/k8s.io/client-go/informers:go_default_library",
+        "//staging/src/k8s.io/client-go/kubernetes/fake: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/controller/volume/attachdetach/metrics/metrics.go

@@ -0,0 +1,136 @@
+/*
+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 metrics
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/golang/glog"
+	"github.com/prometheus/client_golang/prometheus"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/types"
+	corelisters "k8s.io/client-go/listers/core/v1"
+	"k8s.io/kubernetes/pkg/controller/volume/attachdetach/util"
+	"k8s.io/kubernetes/pkg/volume"
+)
+
+var (
+	inUseVolumeMetricDesc = prometheus.NewDesc(
+		prometheus.BuildFQName("", "storage_count", "attachable_volumes_in_use"),
+		"Measure number of volumes in use",
+		[]string{"node", "volume_plugin"}, nil)
+)
+var registerMetrics sync.Once
+
+type volumeInUseCollector struct {
+	pvcLister       corelisters.PersistentVolumeClaimLister
+	podLister       corelisters.PodLister
+	pvLister        corelisters.PersistentVolumeLister
+	volumePluginMgr *volume.VolumePluginMgr
+}
+
+// nodeVolumeCount contains map of {"nodeName": {"pluginName": volume_count }}
+// For example :
+//     node 172.168.1.100.ec2.internal has 10 EBS and 3 glusterfs PVC in use
+//     {"172.168.1.100.ec2.internal": {"aws-ebs": 10, "glusterfs": 3}}
+type nodeVolumeCount map[types.NodeName]map[string]int
+
+// Register registers pvc's in-use metrics
+func Register(pvcLister corelisters.PersistentVolumeClaimLister,
+	pvLister corelisters.PersistentVolumeLister,
+	podLister corelisters.PodLister,
+	pluginMgr *volume.VolumePluginMgr) {
+	registerMetrics.Do(func() {
+		prometheus.MustRegister(newVolumeInUseCollector(pvcLister, podLister, pvLister, pluginMgr))
+	})
+
+}
+
+func (volumeInUse nodeVolumeCount) add(nodeName types.NodeName, pluginName string) {
+	nodeCount, ok := volumeInUse[nodeName]
+	if !ok {
+		nodeCount = map[string]int{}
+	}
+	nodeCount[pluginName]++
+	volumeInUse[nodeName] = nodeCount
+}
+
+func newVolumeInUseCollector(
+	pvcLister corelisters.PersistentVolumeClaimLister,
+	podLister corelisters.PodLister,
+	pvLister corelisters.PersistentVolumeLister,
+	pluginMgr *volume.VolumePluginMgr) *volumeInUseCollector {
+	fmt.Println("Doing this crap again")
+	return &volumeInUseCollector{pvcLister, podLister, pvLister, pluginMgr}
+}
+
+// Check if our collector implements necessary collector interface
+var _ prometheus.Collector = &volumeInUseCollector{}
+
+func (collector *volumeInUseCollector) Describe(ch chan<- *prometheus.Desc) {
+	ch <- inUseVolumeMetricDesc
+}
+
+func (collector *volumeInUseCollector) Collect(ch chan<- prometheus.Metric) {
+	nodeVolumeMap := collector.getVolumeInUseCount()
+	for nodeName, pluginCount := range nodeVolumeMap {
+		for pluginName, count := range pluginCount {
+			metric, err := prometheus.NewConstMetric(inUseVolumeMetricDesc,
+				prometheus.GaugeValue,
+				float64(count),
+				string(nodeName),
+				pluginName)
+			if err != nil {
+				glog.Warningf("Failed to create metric : %v", err)
+			}
+			ch <- metric
+		}
+	}
+}
+
+func (collector *volumeInUseCollector) getVolumeInUseCount() nodeVolumeCount {
+	pods, err := collector.podLister.List(labels.Everything())
+	if err != nil {
+		glog.Errorf("Error getting pod list")
+		return nil
+	}
+
+	nodeVolumeMap := make(nodeVolumeCount)
+	for _, pod := range pods {
+		if len(pod.Spec.Volumes) <= 0 {
+			continue
+		}
+
+		nodeName := types.NodeName(pod.Spec.NodeName)
+		if nodeName == "" {
+			continue
+		}
+		for _, podVolume := range pod.Spec.Volumes {
+			volumeSpec, err := util.CreateVolumeSpec(podVolume, pod.Namespace, collector.pvcLister, collector.pvLister)
+			if err != nil {
+				continue
+			}
+			volumePlugin, err := collector.volumePluginMgr.FindPluginBySpec(volumeSpec)
+			if err != nil {
+				continue
+			}
+			nodeVolumeMap.add(nodeName, volumePlugin.GetPluginName())
+		}
+	}
+	return nodeVolumeMap
+}

pkg/controller/volume/attachdetach/metrics/metrics_test.go

@@ -0,0 +1,121 @@
+/*
+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 metrics
+
+import (
+	"testing"
+
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes/fake"
+	"k8s.io/kubernetes/pkg/controller"
+	volumetesting "k8s.io/kubernetes/pkg/volume/testing"
+)
+
+func TestMetricCollection(t *testing.T) {
+	fakeVolumePluginMgr, _ := volumetesting.GetTestVolumePluginMgr(t)
+	fakeClient := &fake.Clientset{}
+
+	fakeInformerFactory := informers.NewSharedInformerFactory(fakeClient, controller.NoResyncPeriodFunc())
+	fakePodInformer := fakeInformerFactory.Core().V1().Pods()
+	pod := &v1.Pod{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "metric-test-pod",
+			UID:       "metric-test-pod-uid",
+			Namespace: "metric-test",
+		},
+		Spec: v1.PodSpec{
+			NodeName: "metric-test-host",
+			Volumes: []v1.Volume{
+				{
+					Name: "metric-test-volume-name",
+					VolumeSource: v1.VolumeSource{
+						PersistentVolumeClaim: &v1.PersistentVolumeClaimVolumeSource{
+							ClaimName: "metric-test-pvc",
+						},
+					},
+				},
+			},
+		},
+		Status: v1.PodStatus{
+			Phase: v1.PodPhase("Running"),
+		},
+	}
+
+	fakePodInformer.Informer().GetStore().Add(pod)
+	pvcInformer := fakeInformerFactory.Core().V1().PersistentVolumeClaims()
+	pvInformer := fakeInformerFactory.Core().V1().PersistentVolumes()
+
+	pvc := &v1.PersistentVolumeClaim{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "metric-test-pvc",
+			Namespace: "metric-test",
+			UID:       "metric-test-pvc-1",
+		},
+		Spec: v1.PersistentVolumeClaimSpec{
+			AccessModes: []v1.PersistentVolumeAccessMode{v1.ReadOnlyMany, v1.ReadWriteOnce},
+			Resources: v1.ResourceRequirements{
+				Requests: v1.ResourceList{
+					v1.ResourceName(v1.ResourceStorage): resource.MustParse("2G"),
+				},
+			},
+			VolumeName: "test-metric-pv-1",
+		},
+		Status: v1.PersistentVolumeClaimStatus{
+			Phase: v1.ClaimBound,
+		},
+	}
+	pv := &v1.PersistentVolume{
+		ObjectMeta: metav1.ObjectMeta{
+			UID:  "test-metric-pv-1",
+			Name: "test-metric-pv-1",
+		},
+		Spec: v1.PersistentVolumeSpec{
+			Capacity: v1.ResourceList{
+				v1.ResourceName(v1.ResourceStorage): resource.MustParse("5G"),
+			},
+			PersistentVolumeSource: v1.PersistentVolumeSource{
+				GCEPersistentDisk: &v1.GCEPersistentDiskVolumeSource{},
+			},
+			AccessModes: []v1.PersistentVolumeAccessMode{v1.ReadWriteOnce, v1.ReadOnlyMany},
+			// this one we're pretending is already bound
+			ClaimRef: &v1.ObjectReference{UID: "metric-test-pvc-1", Namespace: "metric-test"},
+		},
+	}
+	pvcInformer.Informer().GetStore().Add(pvc)
+	pvInformer.Informer().GetStore().Add(pv)
+	pvcLister := pvcInformer.Lister()
+	pvLister := pvInformer.Lister()
+
+	metricCollector := newVolumeInUseCollector(pvcLister, fakePodInformer.Lister(), pvLister, fakeVolumePluginMgr)
+	nodeUseMap := metricCollector.getVolumeInUseCount()
+	if len(nodeUseMap) < 1 {
+		t.Errorf("Expected one volume in use got %d", len(nodeUseMap))
+	}
+	testNodeMetric := nodeUseMap["metric-test-host"]
+	pluginUseCount, ok := testNodeMetric["fake-plugin"]
+	if !ok {
+		t.Errorf("Expected fake plugin pvc got nothing")
+	}
+
+	if pluginUseCount < 1 {
+		t.Errorf("Expected at least in-use volume metric got %d", pluginUseCount)
+	}
+
+}