Fix nginx ingress variables for definitions with Backend

test/e2e/ingress/without_host.go

@@ -22,6 +22,9 @@ import (
 	"strings"
 
 	"github.com/onsi/ginkgo"
+	networking "k8s.io/api/networking/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/intstr"
 
 	"k8s.io/ingress-nginx/test/e2e/framework"
 )
@@ -49,4 +52,42 @@ var _ = framework.IngressNginxDescribe("[Ingress] definition without host", func
 			Expect().
 			Status(http.StatusOK)
 	})
+
+	ginkgo.It("should set ingress details variables for ingresses with host without IngressRuleValue, only Backend", func() {
+		f.NewEchoDeployment()
+
+		ing := &networking.Ingress{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "backend",
+				Namespace: f.Namespace,
+			},
+			Spec: networking.IngressSpec{
+				Backend: &networking.IngressBackend{
+					ServiceName: framework.EchoService,
+					ServicePort: intstr.FromInt(80),
+				},
+				Rules: []networking.IngressRule{
+					{
+						Host: "only-backend",
+					},
+				},
+			},
+		}
+		f.EnsureIngress(ing)
+
+		f.WaitForNginxServer("only-backend",
+			func(server string) bool {
+				return strings.Contains(server, fmt.Sprintf(`set $namespace "%v";`, f.Namespace)) &&
+					strings.Contains(server, fmt.Sprintf(`set $ingress_name "%v";`, ing.Name)) &&
+					strings.Contains(server, fmt.Sprintf(`set $service_name "%v";`, framework.EchoService)) &&
+					strings.Contains(server, `set $service_port "80";`) &&
+					strings.Contains(server, `set $location_path "/";`)
+			})
+
+		f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", "only-backend").
+			Expect().
+			Status(http.StatusOK)
+	})
 })