Merge pull request kubernetes#1648 from Serializator/add-kube-horizontalpodautoscaler-info-metric

Add "kube_horizontalpodautoscaler_info" metric

Author: k8s-ci-robot

docs/horizontalpodautoscaler-metrics.md

@@ -2,6 +2,7 @@
 
 | Metric name                       | Metric type | Labels/tags                                                   | Status |
 | --------------------------------  | ----------- | ------------------------------------------------------------- | ------ |
+| kube_horizontalpodautoscaler_info                     | Gauge       | `horizontalpodautoscaler`=&lt;hpa-name&gt; <br> `namespace`=&lt;hpa-namespace&gt; <br> `scaletargetref_api_version`=&lt;hpa-target-api-version&gt; <br> `scaletargetref_kind`=&lt;hpa-target-kind&gt; <br> `scaletargetref_name`=&lt;hpa-target-name&gt; | EXPERIMENTAL |
 | kube_horizontalpodautoscaler_annotations              | Gauge       | `horizontalpodautoscaler`=&lt;hpa-name&gt; <br> `namespace`=&lt;hpa-namespace&gt; | EXPERIMENTAL |
 | kube_horizontalpodautoscaler_labels                   | Gauge       | `horizontalpodautoscaler`=&lt;hpa-name&gt; <br> `namespace`=&lt;hpa-namespace&gt; | STABLE |
 | kube_horizontalpodautoscaler_metadata_generation      | Gauge       | `horizontalpodautoscaler`=&lt;hpa-name&gt; <br> `namespace`=&lt;hpa-namespace&gt; | STABLE |

internal/store/horizontalpodautoscaler.go

@@ -56,6 +56,29 @@ var (
 
 func hpaMetricFamilies(allowAnnotationsList, allowLabelsList []string) []generator.FamilyGenerator {
 	return []generator.FamilyGenerator{
+		*generator.NewFamilyGenerator(
+			"kube_horizontalpodautoscaler_info",
+			"Information about this autoscaler.",
+			metric.Gauge,
+			"",
+			wrapHPAFunc(func(a *autoscaling.HorizontalPodAutoscaler) *metric.Family {
+				labelKeys := []string{"scaletargetref_kind", "scaletargetref_name"}
+				labelValues := []string{a.Spec.ScaleTargetRef.Kind, a.Spec.ScaleTargetRef.Name}
+				if a.Spec.ScaleTargetRef.APIVersion != "" {
+					labelKeys = append([]string{"scaletargetref_api_version"}, labelKeys...)
+					labelValues = append([]string{a.Spec.ScaleTargetRef.APIVersion}, labelValues...)
+				}
+				return &metric.Family{
+					Metrics: []*metric.Metric{
+						{
+							LabelKeys:   labelKeys,
+							LabelValues: labelValues,
+							Value:       1,
+						},
+					},
+				}
+			}),
+		),
 		*generator.NewFamilyGenerator(
 			"kube_horizontalpodautoscaler_metadata_generation",
 			"The generation observed by the HorizontalPodAutoscaler controller.",

internal/store/horizontalpodautoscaler_test.go

@@ -35,6 +35,7 @@ func TestHPAStore(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_horizontalpodautoscaler_info Information about this autoscaler.
 		# HELP kube_horizontalpodautoscaler_annotations Kubernetes annotations converted to Prometheus labels.
 		# HELP kube_horizontalpodautoscaler_labels Kubernetes labels converted to Prometheus labels.
 		# HELP kube_horizontalpodautoscaler_metadata_generation The generation observed by the HorizontalPodAutoscaler controller.
@@ -44,6 +45,7 @@ func TestHPAStore(t *testing.T) {
 		# HELP kube_horizontalpodautoscaler_status_condition The condition of this autoscaler.
 		# HELP kube_horizontalpodautoscaler_status_current_replicas Current number of replicas of pods managed by this autoscaler.
 		# HELP kube_horizontalpodautoscaler_status_desired_replicas Desired number of replicas of pods managed by this autoscaler.
+		# TYPE kube_horizontalpodautoscaler_info gauge
 		# TYPE kube_horizontalpodautoscaler_annotations gauge
 		# TYPE kube_horizontalpodautoscaler_labels gauge
 		# TYPE kube_horizontalpodautoscaler_metadata_generation gauge
@@ -183,6 +185,7 @@ func TestHPAStore(t *testing.T) {
 				},
 			},
 			Want: metadata + `
+				kube_horizontalpodautoscaler_info{horizontalpodautoscaler="hpa1",namespace="ns1",scaletargetref_api_version="apps/v1",scaletargetref_kind="Deployment",scaletargetref_name="deployment1"} 1
 				kube_horizontalpodautoscaler_annotations{horizontalpodautoscaler="hpa1",namespace="ns1"} 1
 				kube_horizontalpodautoscaler_labels{horizontalpodautoscaler="hpa1",namespace="ns1"} 1
 				kube_horizontalpodautoscaler_metadata_generation{horizontalpodautoscaler="hpa1",namespace="ns1"} 2
@@ -203,6 +206,7 @@ func TestHPAStore(t *testing.T) {
 				kube_horizontalpodautoscaler_status_desired_replicas{horizontalpodautoscaler="hpa1",namespace="ns1"} 2
 			`,
 			MetricNames: []string{
+				"kube_horizontalpodautoscaler_info",
 				"kube_horizontalpodautoscaler_metadata_generation",
 				"kube_horizontalpodautoscaler_spec_max_replicas",
 				"kube_horizontalpodautoscaler_spec_min_replicas",
@@ -278,9 +282,8 @@ func TestHPAStore(t *testing.T) {
 						},
 					},
 					ScaleTargetRef: autoscaling.CrossVersionObjectReference{
-						APIVersion: "apps/v1",
-						Kind:       "Deployment",
-						Name:       "deployment1",
+						Kind: "Deployment",
+						Name: "deployment1",
 					},
 				},
 				Status: autoscaling.HorizontalPodAutoscalerStatus{
@@ -341,6 +344,7 @@ func TestHPAStore(t *testing.T) {
 				},
 			},
 			Want: metadata + `
+				kube_horizontalpodautoscaler_info{horizontalpodautoscaler="hpa2",namespace="ns1",scaletargetref_kind="Deployment",scaletargetref_name="deployment1"} 1
 				kube_horizontalpodautoscaler_annotations{annotation_app_k8s_io_owner="@foo",horizontalpodautoscaler="hpa2",namespace="ns1"} 1
 				kube_horizontalpodautoscaler_labels{horizontalpodautoscaler="hpa2",namespace="ns1"} 1
 				kube_horizontalpodautoscaler_metadata_generation{horizontalpodautoscaler="hpa2",namespace="ns1"} 2
@@ -357,6 +361,7 @@ func TestHPAStore(t *testing.T) {
 				kube_horizontalpodautoscaler_status_desired_replicas{horizontalpodautoscaler="hpa2",namespace="ns1"} 2
 			`,
 			MetricNames: []string{
+				"kube_horizontalpodautoscaler_info",
 				"kube_horizontalpodautoscaler_metadata_generation",
 				"kube_horizontalpodautoscaler_spec_max_replicas",
 				"kube_horizontalpodautoscaler_spec_min_replicas",