prefix GVK labels in CustomResourceMonitoring

This will prefix the auto-generated GVK labels for CustomResources with
customresource_ to make it a bit more clear that these labels got generated.

Signed-off-by: Mario Constanti <mario@constanti.de>

docs/customresourcestate-metrics.md

@@ -49,7 +49,7 @@ spec:
           - --resources=certificatesigningrequests,configmaps,cronjobs,daemonsets,deployments,endpoints,foos,horizontalpodautoscalers,ingresses,jobs,limitranges,mutatingwebhookconfigurations,namespaces,networkpolicies,nodes,persistentvolumeclaims,persistentvolumes,poddisruptionbudgets,pods,replicasets,replicationcontrollers,resourcequotas,secrets,services,statefulsets,storageclasses,validatingwebhookconfigurations,volumeattachments,verticalpodautoscalers
 ```
 
-NOTE: The `group`, `version`, and `kind` common labels are reserved, and will be overwritten by the values from the `groupVersionKind` field.
+NOTE: The `customresource_group`, `customresource_version`, and `customresource_kind` common labels are reserved, and will be overwritten by the values from the `groupVersionKind` field.
 
 ### Examples
 

pkg/customresourcestate/config.go

@@ -26,6 +26,10 @@ import (
 	"k8s.io/kube-state-metrics/v2/pkg/customresource"
 )
 
+// customResourceState is used to prefix the auto-generated GVK labels as well as an appendix for the metric itself
+// if no custom metric name is defined
+const customResourceState string = "customresource"
+
 // Metrics is the top level configuration object.
 type Metrics struct {
 	Spec MetricsSpec `yaml:"spec" json:"spec"`
@@ -64,7 +68,7 @@ type Resource struct {
 func (r Resource) GetMetricNamePrefix() string {
 	p := r.MetricNamePrefix
 	if p == nil {
-		return "kube_crd"
+		return "kube_" + customResourceState
 	}
 	return *p
 }

pkg/customresourcestate/custom_resource_metrics_test.go

@@ -17,18 +17,25 @@ limitations under the License.
 package customresourcestate
 
 import (
+	"encoding/json"
+	"reflect"
 	"testing"
+
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/utils/pointer"
 )
 
 func TestNewCustomResourceMetrics(t *testing.T) {
+
 	tests := []struct {
-		r       Resource
+		r          Resource
-		wantErr bool
+		wantErr    bool
-		name    string
+		wantResult *customResourceMetrics
+		name       string
 	}{
 		{
 			// https://github.com/kubernetes/kube-state-metrics/issues/1886
-			name: "dynamic metric type (not just hardcoded to gauge)",
+			name: "cr metric with dynamic metric type",
 			r: Resource{
 				GroupVersionKind: GroupVersionKind{
 					Group:   "apps",
@@ -39,6 +46,9 @@ func TestNewCustomResourceMetrics(t *testing.T) {
 					LabelsFromPath: map[string][]string{
 						"name": {"metadata", "name"},
 					},
+					CommonLabels: map[string]string{
+						"hello": "world",
+					},
 				},
 				Metrics: []Generator{
 					{
@@ -60,16 +70,178 @@ func TestNewCustomResourceMetrics(t *testing.T) {
 				},
 			},
 			wantErr: false,
+			wantResult: &customResourceMetrics{
+				MetricNamePrefix: "kube_customresource",
+				GroupVersionKind: schema.GroupVersionKind{
+					Group:   "apps",
+					Version: "v1",
+					Kind:    "Deployment",
+				},
+				ResourceName: "deployments",
+				Families: []compiledFamily{
+					{
+						Name: "kube_customresource_test_metrics",
+						Help: "metrics for testing",
+						Each: &compiledInfo{},
+						Labels: map[string]string{
+							"customresource_group":   "apps",
+							"customresource_kind":    "Deployment",
+							"customresource_version": "v1",
+							"hello":                  "world",
+						},
+						LabelFromPath: map[string]valuePath{
+							"name": mustCompilePath(t, "metadata", "name"),
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "cr metric with custom prefix",
+			r: Resource{
+				GroupVersionKind: GroupVersionKind{
+					Group:   "apps",
+					Version: "v1",
+					Kind:    "Deployment",
+				},
+				Labels: Labels{
+					LabelsFromPath: map[string][]string{
+						"name": {"metadata", "name"},
+					},
+					CommonLabels: map[string]string{
+						"hello": "world",
+					},
+				},
+				Metrics: []Generator{
+					{
+						Name: "test_metrics",
+						Help: "metrics for testing",
+						Each: Metric{
+							Type: MetricTypeInfo,
+							Info: &MetricInfo{
+								MetricMeta: MetricMeta{
+									Path: []string{
+										"metadata",
+										"annotations",
+									},
+								},
+								LabelFromKey: "test",
+							},
+						},
+					},
+				},
+				MetricNamePrefix: pointer.String("apps_deployment"),
+			},
+			wantErr: false,
+			wantResult: &customResourceMetrics{
+				MetricNamePrefix: "apps_deployment",
+				GroupVersionKind: schema.GroupVersionKind{
+					Group:   "apps",
+					Version: "v1",
+					Kind:    "Deployment",
+				},
+				ResourceName: "deployments",
+				Families: []compiledFamily{
+					{
+						Name: "apps_deployment_test_metrics",
+						Help: "metrics for testing",
+						Each: &compiledInfo{},
+						Labels: map[string]string{
+							"customresource_group":   "apps",
+							"customresource_kind":    "Deployment",
+							"customresource_version": "v1",
+							"hello":                  "world",
+						},
+						LabelFromPath: map[string]valuePath{
+							"name": mustCompilePath(t, "metadata", "name"),
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "cr metric with custom prefix - expect error",
+			r: Resource{
+				GroupVersionKind: GroupVersionKind{
+					Group:   "apps",
+					Version: "v1",
+					Kind:    "Deployment",
+				},
+				Labels: Labels{
+					LabelsFromPath: map[string][]string{
+						"name": {"metadata", "name"},
+					},
+					CommonLabels: map[string]string{
+						"hello": "world",
+					},
+				},
+				Metrics: []Generator{
+					{
+						Name: "test_metrics",
+						Help: "metrics for testing",
+						Each: Metric{
+							Type: MetricTypeInfo,
+							Info: &MetricInfo{
+								MetricMeta: MetricMeta{
+									Path: []string{
+										"metadata",
+										"annotations",
+									},
+								},
+								LabelFromKey: "test",
+							},
+						},
+					},
+				},
+				MetricNamePrefix: pointer.String("apps_deployment"),
+			},
+			wantErr: true,
+			wantResult: &customResourceMetrics{
+				GroupVersionKind: schema.GroupVersionKind{
+					Group:   "apps",
+					Version: "v1",
+					Kind:    "Deployment",
+				},
+				ResourceName: "deployments",
+				Families: []compiledFamily{
+					{
+						Name: "apps_deployment_test_metrics",
+						Help: "metrics for testing",
+						Each: &compiledInfo{},
+						Labels: map[string]string{
+							"customresource_group":   "apps",
+							"customresource_kind":    "Deployment",
+							"customresource_version": "v1",
+							"hello":                  "world",
+						},
+						LabelFromPath: map[string]valuePath{
+							"name": mustCompilePath(t, "metadata", "name"),
+						},
+					},
+				},
+			},
 		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			v, err := NewCustomResourceMetrics(tt.r)
-			expectedError := v.(*customResourceMetrics).Families[0].Each.Type() != "info"
+			if err != nil {
-			if (err != nil) != tt.wantErr || expectedError {
+				t.Errorf(err.Error())
-				t.Errorf("NewCustomResourceMetrics() error = %v, wantErr %v", err, tt.wantErr)
+			}
-				return
+
+			// convert to JSON for easier nil comparison
+			ttWantJSON, _ := json.Marshal(tt.wantResult)
+			customResourceMetricJSON, _ := json.Marshal(v.(*customResourceMetrics))
+
+			if !tt.wantErr && !reflect.DeepEqual(ttWantJSON, customResourceMetricJSON) {
+				t.Errorf("NewCustomResourceMetrics: error expected %v", tt.wantErr)
+				t.Errorf("NewCustomResourceMetrics:\n %#v\n is not deep equal\n %#v", v, tt.wantResult)
+			}
+
+			if tt.wantErr && reflect.DeepEqual(ttWantJSON, customResourceMetricJSON) {
+				t.Errorf("NewCustomResourceMetrics: error expected %v", tt.wantErr)
+				t.Errorf("NewCustomResourceMetrics:\n %#v\n is not deep equal\n %#v", v, tt.wantResult)
 			}
 		})
 	}

pkg/customresourcestate/registry_factory.go

@@ -38,9 +38,9 @@ func compile(resource Resource) ([]compiledFamily, error) {
 	if resource.CommonLabels == nil {
 		resource.CommonLabels = map[string]string{}
 	}
-	resource.CommonLabels["group"] = resource.GroupVersionKind.Group
+	resource.CommonLabels[customResourceState+"_group"] = resource.GroupVersionKind.Group
-	resource.CommonLabels["version"] = resource.GroupVersionKind.Version
+	resource.CommonLabels[customResourceState+"_version"] = resource.GroupVersionKind.Version
-	resource.CommonLabels["kind"] = resource.GroupVersionKind.Kind
+	resource.CommonLabels[customResourceState+"_kind"] = resource.GroupVersionKind.Kind
 	for _, f := range resource.Metrics {
 		family, err := compileFamily(f, resource)
 		if err != nil {

pkg/customresourcestate/registry_factory_test.go

@@ -333,7 +333,7 @@ func Test_fullName(t *testing.T) {
 				resource: r(nil),
 				f:        count,
 			},
-			want: "kube_crd_count",
+			want: "kube_customresource_count",
 		},
 		{
 			name: "no prefix",