Added StatefulSet metrics

Documentation/statefulset-metrics.md

@@ -0,0 +1,8 @@
+# Service Metrics
+ 
+| Metric name| Metric type | Labels/tags |
+| ---------- | ----------- | ----------- |
+| kube_statefulset_status_replicas | Gauge | `statefulset`=&lt;statefulset-name&gt; <br> `namespace`=&lt;statefulset-namespace&gt;  |
+| kube_statefulset_status_observed_generation | Gauge | `statefulset`=&lt;statefulset-name&gt; <br> `namespace`=&lt;statefulset-namespace&gt;  |
+| kube_statefulset_replicas | Gauge | `statefulset`=&lt;statefulset-name&gt; <br> `namespace`=&lt;statefulset-namespace&gt;  |
+| kube_statefulset_metadata_generation | Gauge | `statefulset`=&lt;statefulset-name&gt; <br> `namespace`=&lt;statefulset-namespace&gt;  |

collectors/statefulset.go

@@ -0,0 +1,98 @@
+package collectors
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"k8s.io/client-go/pkg/apis/apps/v1beta1"
+	"github.com/golang/glog"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/cache"
+	"golang.org/x/net/context"
+	"k8s.io/client-go/pkg/api"
+)
+
+var (
+	descStatefulSetStatusReplicas = prometheus.NewDesc(
+		"kube_statefulset_status_replicas",
+		"The number of replicas per StatefulSet.",
+		[]string{"namespace", "statefulset"}, nil,
+	)
+
+	descStatefulSetStatusObservedGeneration = prometheus.NewDesc(
+		"kube_statefulset_status_observed_generation",
+		"The generation observed by the StatefulSet controller.",
+		[]string{"namespace", "statefulset"}, nil,
+	)
+
+	descStatefulSetSpecReplicas = prometheus.NewDesc(
+		"kube_statefulset_replicas",
+		"Number of desired pods for a StatefulSet.",
+		[]string{"namespace", "statefulset"}, nil,
+	)
+
+	descStatefulSetMetadataGeneration = prometheus.NewDesc(
+		"kube_statefulset_metadata_generation",
+		"Sequence number representing a specific generation of the desired state for the StatefulSet.",
+		[]string{"namespace", "statefulset"}, nil,
+	)
+)
+
+type StatefulSetLister func() ([]v1beta1.StatefulSet, error)
+
+func (l StatefulSetLister) List() ([]v1beta1.StatefulSet, error) {
+	return l()
+}
+
+func RegisterStatefulSetCollector(registry prometheus.Registerer, kubeClient kubernetes.Interface) {
+	client := kubeClient.AppsV1beta1().RESTClient()
+	dlw := cache.NewListWatchFromClient(client, "statefulsets", api.NamespaceAll, nil)
+	dinf := cache.NewSharedInformer(dlw, &v1beta1.StatefulSet{}, resyncPeriod)
+
+	statefulSetLister := StatefulSetLister(func() (statefulSets []v1beta1.StatefulSet, err error) {
+		for _, c := range dinf.GetStore().List() {
+			statefulSets = append(statefulSets, *(c.(*v1beta1.StatefulSet)))
+		}
+		return statefulSets, nil
+	})
+
+	registry.MustRegister(&statefulSetCollector{store: statefulSetLister})
+	go dinf.Run(context.Background().Done())
+}
+
+type statefulSetStore interface {
+	List() (statefulSets []v1beta1.StatefulSet, err error)
+}
+
+type statefulSetCollector struct {
+	store statefulSetStore
+}
+
+// Describe implements the prometheus.Collector interface.
+func (dc *statefulSetCollector) Describe(ch chan<- *prometheus.Desc) {
+	ch <- descStatefulSetStatusReplicas
+	ch <- descStatefulSetStatusObservedGeneration
+	ch <- descStatefulSetSpecReplicas
+	ch <- descStatefulSetMetadataGeneration
+}
+
+// Collect implements the prometheus.Collector interface.
+func (sc *statefulSetCollector) Collect(ch chan<- prometheus.Metric) {
+	dpls, err := sc.store.List()
+	if err != nil {
+		glog.Errorf("listing statefulsets failed: %s", err)
+		return
+	}
+	for _, d := range dpls {
+		sc.collectStatefulSet(ch, d)
+	}
+}
+
+func (dc *statefulSetCollector) collectStatefulSet(ch chan<- prometheus.Metric, statefulSet v1beta1.StatefulSet) {
+	addGauge := func(desc *prometheus.Desc, v float64, lv ...string) {
+		lv = append([]string{statefulSet.Namespace, statefulSet.Name}, lv...)
+		ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, v, lv...)
+	}
+	addGauge(descStatefulSetStatusReplicas, float64(statefulSet.Status.Replicas))
+	addGauge(descStatefulSetStatusObservedGeneration, float64(*statefulSet.Status.ObservedGeneration))
+	addGauge(descStatefulSetSpecReplicas, float64(*statefulSet.Spec.Replicas))
+	addGauge(descStatefulSetMetadataGeneration, float64(statefulSet.ObjectMeta.Generation))
+} 

collectors/statefulset_test.go

@@ -0,0 +1,96 @@
+package collectors
+
+import (
+	"k8s.io/client-go/pkg/apis/apps/v1beta1"
+	"testing"
+	"k8s.io/client-go/pkg/api/v1"
+)
+
+var (
+	statefulSet1Replicas int32 = 3
+	statefulSet2Replicas int32 = 6
+
+	statefulSet1ObservedGeneration int64 = 1
+	statefulSet2ObservedGeneration int64 = 2
+)
+
+type mockStatefulSetStore struct {
+	f func() ([]v1beta1.StatefulSet, error)
+}
+
+func (ds mockStatefulSetStore) List() (deployments []v1beta1.StatefulSet, err error) {
+	return ds.f()
+}
+
+func TestStatefuleSetCollector(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 kube_statefulset_status_replicas The number of replicas per StatefulSet.
+ 		# TYPE kube_statefulset_status_replicas gauge
+ 		# HELP kube_statefulset_status_observed_generation The generation observed by the StatefulSet controller.
+ 		# TYPE kube_statefulset_status_observed_generation gauge
+ 		# HELP kube_statefulset_replicas Number of desired pods for a StatefulSet.
+ 		# TYPE kube_statefulset_replicas gauge
+ 		# HELP kube_statefulset_metadata_generation Sequence number representing a specific generation of the desired state for the StatefulSet.
+ 		# TYPE kube_statefulset_metadata_generation gauge
+ 	`
+	cases := []struct {
+		depls []v1beta1.StatefulSet
+		want  string
+	}{
+		{
+			depls: []v1beta1.StatefulSet{
+				{
+					ObjectMeta: v1.ObjectMeta{
+						Name:       "statefulset1",
+						Namespace:  "ns1",
+						Generation: 3,
+					},
+					Spec: v1beta1.StatefulSetSpec{
+						Replicas:            &statefulSet1Replicas,
+						ServiceName:   		 "statefulset1service",
+					},
+					Status: v1beta1.StatefulSetStatus{
+						ObservedGeneration: &statefulSet1ObservedGeneration,
+						Replicas: 2,
+					},
+				}, {
+					ObjectMeta: v1.ObjectMeta{
+						Name:       "statefulset2",
+						Namespace:  "ns2",
+						Generation: 21,
+					},
+					Spec: v1beta1.StatefulSetSpec{
+						Replicas:            &statefulSet2Replicas,
+						ServiceName:   		 "statefulset2service",
+					},
+					Status: v1beta1.StatefulSetStatus{
+						ObservedGeneration: &statefulSet2ObservedGeneration,
+						Replicas: 5,
+					},
+				},
+			},
+			want: metadata + `
+ 				kube_statefulset_status_replicas{namespace="ns1",statefulset="statefulset1"} 2
+ 				kube_statefulset_status_replicas{namespace="ns2",statefulset="statefulset2"} 5
+ 				kube_statefulset_status_observed_generation{namespace="ns1",statefulset="statefulset1"} 1
+ 				kube_statefulset_status_observed_generation{namespace="ns2",statefulset="statefulset2"} 2
+ 				kube_statefulset_replicas{namespace="ns1",statefulset="statefulset1"} 3
+ 				kube_statefulset_replicas{namespace="ns2",statefulset="statefulset2"} 6
+ 				kube_statefulset_metadata_generation{namespace="ns1",statefulset="statefulset1"} 3
+ 				kube_statefulset_metadata_generation{namespace="ns2",statefulset="statefulset2"} 21
+ 			`,
+		},
+	}
+	for _, c := range cases {
+		sc := &statefulSetCollector{
+			store: mockStatefulSetStore{
+				f: func() ([]v1beta1.StatefulSet, error) { return c.depls, nil },
+			},
+		}
+		if err := gatherAndCompare(sc, c.want, nil); err != nil {
+			t.Errorf("unexpected collecting result:\n%s", err)
+		}
+	}
+} 

main.go

@@ -54,6 +54,7 @@ var (
 		"services":               struct{}{},
 		"jobs":                   struct{}{},
 		"cronjobs":               struct{}{},
+		"statefulsets":           struct{}{},
 	}
 	availableCollectors = map[string]func(registry prometheus.Registerer, kubeClient clientset.Interface){
 		"cronjobs":               collectors.RegisterCronJobCollector,
@@ -67,6 +68,7 @@ var (
 		"replicationcontrollers": collectors.RegisterReplicationControllerCollector,
 		"resourcequotas":         collectors.RegisterResourceQuotaCollector,
 		"services":               collectors.RegisterServiceCollector,
+		"statefulsets":           collectors.RegisterStatefulSetCollector,
 	}
 )