Remove kube_namespace_annotations metric

Because we do not know what could be in the annotations that are created
by kubernetes, we want to remove all annotation metrics.

Author: lilic

docs/namespace-metrics.md

@@ -4,5 +4,4 @@
 | ---------- | ----------- | ----------- | ----------- |
 | kube_namespace_status_phase| Gauge | `namespace`=&lt;namespace-name&gt; <br> `status`=&lt;Active\|Terminating&gt; | STABLE |
 | kube_namespace_labels | Gauge | `namespace`=&lt;namespace-name&gt; <br> `label_NS_LABEL`=&lt;NS_LABEL&gt; | STABLE |
-| kube_namespace_annotations | Gauge | `namespace`=&lt;namespace-name&gt; <br> `annotation_NS_ANNOTATION`=&lt;NS_ANNOTATION&gt; | STABLE |
 | kube_namespace_created | Gauge | `namespace`=&lt;namespace-name&gt; | STABLE |

internal/store/namespace.go

@@ -32,10 +32,6 @@ var (
 	descNamespaceLabelsHelp          = "Kubernetes labels converted to Prometheus labels."
 	descNamespaceLabelsDefaultLabels = []string{"namespace"}
 
-	descNamespaceAnnotationsName          = "kube_namespace_annotations"
-	descNamespaceAnnotationsHelp          = "Kubernetes annotations converted to Prometheus labels."
-	descNamespaceAnnotationsDefaultLabels = []string{"namespace"}
-
 	namespaceMetricFamilies = []metric.FamilyGenerator{
 		{
 			Name: "kube_namespace_created",
@@ -71,23 +67,6 @@ var (
 				}
 			}),
 		},
-		{
-			Name: descNamespaceAnnotationsName,
-			Type: metric.Gauge,
-			Help: descNamespaceAnnotationsHelp,
-			GenerateFunc: wrapNamespaceFunc(func(n *v1.Namespace) *metric.Family {
-				annotationKeys, annotationValues := kubeAnnotationsToPrometheusLabels(n.Annotations)
-				return &metric.Family{
-					Metrics: []*metric.Metric{
-						{
-							LabelKeys:   annotationKeys,
-							LabelValues: annotationValues,
-							Value:       1,
-						},
-					},
-				}
-			}),
-		},
 		{
 			Name: "kube_namespace_status_phase",
 			Type: metric.Gauge,

internal/store/namespace_test.go

@@ -33,8 +33,6 @@ func TestNamespaceStore(t *testing.T) {
 		# TYPE kube_namespace_created gauge
 		# HELP kube_namespace_labels Kubernetes labels converted to Prometheus labels.
 		# TYPE kube_namespace_labels gauge
-		# HELP kube_namespace_annotations Kubernetes annotations converted to Prometheus labels.
-		# TYPE kube_namespace_annotations gauge
 		# HELP kube_namespace_status_phase kubernetes namespace status phase.
 		# TYPE kube_namespace_status_phase gauge
 	`
@@ -54,7 +52,6 @@ func TestNamespaceStore(t *testing.T) {
 			},
 			Want: `
 				kube_namespace_labels{namespace="nsActiveTest"} 1
-				kube_namespace_annotations{namespace="nsActiveTest"} 1
 				kube_namespace_status_phase{namespace="nsActiveTest",phase="Active"} 1
 				kube_namespace_status_phase{namespace="nsActiveTest",phase="Terminating"} 0
 `,
@@ -73,7 +70,6 @@ func TestNamespaceStore(t *testing.T) {
 			},
 			Want: `
 				kube_namespace_labels{namespace="nsTerminateTest"} 1
-				kube_namespace_annotations{namespace="nsTerminateTest"} 1
 				kube_namespace_status_phase{namespace="nsTerminateTest",phase="Active"} 0
 				kube_namespace_status_phase{namespace="nsTerminateTest",phase="Terminating"} 1
 `,
@@ -87,9 +83,6 @@ func TestNamespaceStore(t *testing.T) {
 					Labels: map[string]string{
 						"app": "example1",
 					},
-					Annotations: map[string]string{
-						"app": "example1",
-					},
 				},
 				Spec: v1.NamespaceSpec{
 					Finalizers: []v1.FinalizerName{v1.FinalizerKubernetes},
@@ -101,7 +94,6 @@ func TestNamespaceStore(t *testing.T) {
 			Want: `
 				kube_namespace_created{namespace="ns1"} 1.5e+09
 				kube_namespace_labels{label_app="example1",namespace="ns1"} 1
-				kube_namespace_annotations{annotation_app="example1",namespace="ns1"} 1
 				kube_namespace_status_phase{namespace="ns1",phase="Active"} 1
 				kube_namespace_status_phase{namespace="ns1",phase="Terminating"} 0
 `,
@@ -114,10 +106,6 @@ func TestNamespaceStore(t *testing.T) {
 						"app": "example2",
 						"l2":  "label2",
 					},
-					Annotations: map[string]string{
-						"app": "example2",
-						"l2":  "label2",
-					},
 				},
 				Spec: v1.NamespaceSpec{
 					Finalizers: []v1.FinalizerName{v1.FinalizerKubernetes},
@@ -128,7 +116,6 @@ func TestNamespaceStore(t *testing.T) {
 			},
 			Want: `
 				kube_namespace_labels{label_app="example2",label_l2="label2",namespace="ns2"} 1
-				kube_namespace_annotations{annotation_app="example2",annotation_l2="label2",namespace="ns2"} 1
 				kube_namespace_status_phase{namespace="ns2",phase="Active"} 1
 				kube_namespace_status_phase{namespace="ns2",phase="Terminating"} 0
 `,

internal/store/utils.go

@@ -70,18 +70,6 @@ func kubeLabelsToPrometheusLabels(labels map[string]string) ([]string, []string)
 	return labelKeys, labelValues
 }
 
-func kubeAnnotationsToPrometheusLabels(annotations map[string]string) ([]string, []string) {
-	annotationKeys := make([]string, len(annotations))
-	annotationValues := make([]string, len(annotations))
-	i := 0
-	for k, v := range annotations {
-		annotationKeys[i] = "annotation_" + sanitizeLabelName(k)
-		annotationValues[i] = v
-		i++
-	}
-	return annotationKeys, annotationValues
-}
-
 func sanitizeLabelName(s string) string {
 	return invalidLabelCharRE.ReplaceAllString(s, "_")
 }

internal/store/utils_test.go

@@ -189,67 +189,3 @@ func TestKubeLabelsToPrometheusLabels(t *testing.T) {
 	}
 
 }
-
-func TestKubeAnnotationsToPrometheusLabels(t *testing.T) {
-	testCases := []struct {
-		kubeAnnotations map[string]string
-		expectKeys      []string
-		expectValues    []string
-	}{
-		{
-			kubeAnnotations: map[string]string{
-				"app1": "normal",
-			},
-			expectKeys:   []string{"annotation_app1"},
-			expectValues: []string{"normal"},
-		},
-		{
-			kubeAnnotations: map[string]string{
-				"0_app3": "starts_with_digit",
-			},
-			expectKeys:   []string{"annotation_0_app3"},
-			expectValues: []string{"starts_with_digit"},
-		},
-		{
-			kubeAnnotations: map[string]string{
-				"": "empty",
-			},
-			expectKeys:   []string{"annotation_"},
-			expectValues: []string{"empty"},
-		},
-		{
-			kubeAnnotations: map[string]string{
-				"$app4": "special_char",
-			},
-			expectKeys:   []string{"annotation__app4"},
-			expectValues: []string{"special_char"},
-		},
-		{
-			kubeAnnotations: map[string]string{
-				"_app5": "starts_with_underscore",
-			},
-			expectKeys:   []string{"annotation__app5"},
-			expectValues: []string{"starts_with_underscore"},
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(fmt.Sprintf("kubeannotations input=%v , expected prometheus keys=%v, expected prometheus values=%v", tc.kubeAnnotations, tc.expectKeys, tc.expectValues), func(t *testing.T) {
-			annotationKeys, annotationValues := kubeAnnotationsToPrometheusLabels(tc.kubeAnnotations)
-			if len(annotationKeys) != len(tc.expectKeys) {
-				t.Errorf("Got Prometheus label keys with len %d but expected %d", len(annotationKeys), len(tc.expectKeys))
-			}
-
-			if len(annotationValues) != len(tc.expectValues) {
-				t.Errorf("Got Prometheus label values with len %d but expected %d", len(annotationValues), len(tc.expectValues))
-			}
-
-			for i := range tc.expectKeys {
-				if !(tc.expectKeys[i] == annotationKeys[i] && tc.expectValues[i] == annotationValues[i]) {
-					t.Errorf("Got Prometheus label %q: %q but expected %q: %q", annotationKeys[i], annotationValues[i], tc.expectKeys[i], tc.expectValues[i])
-				}
-			}
-		})
-	}
-
-}