add label selector for nats-manager

Adds a labelselector for nats-manager instance.

internal/label/label.go

@@ -0,0 +1,26 @@
+package label
+
+import (
+	"k8s.io/apimachinery/pkg/labels"
+)
+
+const (
+	// Kubernetes label keys used by nats-manager.
+	KeyComponent = "app.kubernetes.io/component"
+	KeyCreatedBy = "app.kubernetes.io/created-by"
+	KeyInstance  = "app.kubernetes.io/instance"
+	KeyManagedBy = "app.kubernetes.io/managed-by"
+	KeyName      = "app.kubernetes.io/name"
+	KeyPartOf    = "app.kubernetes.io/part-of"
+	KeyDashboard = "kyma-project.io/dashboard"
+
+	// Kubernetes label keys used by nats-manager.
+	ValueNATS        = "nats"
+	ValueNATSManager = "nats-manager"
+)
+
+// SelectorInstanceNATS returns a labelselector for instance ("app.kubernetes.io/instance") as usesd
+// by the nats-manager.
+func SelectorInstanceNATS() labels.Selector {
+	return labels.SelectorFromSet(map[string]string{KeyInstance: ValueNATSManager})
+}

internal/label/label_test.go

@@ -0,0 +1,23 @@
+package label_test
+
+import (
+	"reflect"
+	"testing"
+
+	"k8s.io/apimachinery/pkg/labels"
+
+	"github.com/kyma-project/nats-manager/internal/label"
+)
+
+func TestSelectorInstanceNATS(t *testing.T) {
+	// arrange
+	wantedSelector := labels.SelectorFromSet(map[string]string{"app.kubernetes.io/instance": "nats-manager"})
+
+	// act
+	actualSelector := label.SelectorInstanceNATS()
+
+	// assert
+	if !reflect.DeepEqual(wantedSelector, actualSelector) {
+		t.Errorf("Expected %v, but got %v", wantedSelector, actualSelector)
+	}
+}