Support ingresses without a host (#406)

fixes #370

provider/kubernetes.go

@@ -162,9 +162,11 @@ func (provider *Kubernetes) loadIngresses(k8sClient k8s.Client) (*types.Configur
 						Routes:         make(map[string]types.Route),
 					}
 				}
-				if _, exists := templateObjects.Frontends[r.Host+pa.Path].Routes[r.Host]; !exists {
-					templateObjects.Frontends[r.Host+pa.Path].Routes[r.Host] = types.Route{
-						Rule: "Host:" + r.Host,
+				if len(r.Host) > 0 {
+					if _, exists := templateObjects.Frontends[r.Host+pa.Path].Routes[r.Host]; !exists {
+						templateObjects.Frontends[r.Host+pa.Path].Routes[r.Host] = types.Route{
+							Rule: "Host:" + r.Host,
+						}
 					}
 				}
 				if len(pa.Path) > 0 {

provider/kubernetes_test.go

@@ -1060,6 +1060,93 @@ func TestLoadMultipleNamespacedIngresses(t *testing.T) {
 	}
 }
 
+func TestHostlessIngress(t *testing.T) {
+	ingresses := []k8s.Ingress{{
+		ObjectMeta: k8s.ObjectMeta{
+			Namespace: "awesome",
+		},
+		Spec: k8s.IngressSpec{
+			Rules: []k8s.IngressRule{
+				{
+					IngressRuleValue: k8s.IngressRuleValue{
+						HTTP: &k8s.HTTPIngressRuleValue{
+							Paths: []k8s.HTTPIngressPath{
+								{
+									Path: "/bar",
+									Backend: k8s.IngressBackend{
+										ServiceName: "service1",
+										ServicePort: k8s.FromInt(801),
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}}
+	services := []k8s.Service{
+		{
+			ObjectMeta: k8s.ObjectMeta{
+				Name:      "service1",
+				Namespace: "awesome",
+				UID:       "1",
+			},
+			Spec: k8s.ServiceSpec{
+				ClusterIP: "10.0.0.1",
+				Ports: []k8s.ServicePort{
+					{
+						Name: "http",
+						Port: 801,
+					},
+				},
+			},
+		},
+	}
+	watchChan := make(chan interface{})
+	client := clientMock{
+		ingresses: ingresses,
+		services:  services,
+		watchChan: watchChan,
+	}
+	provider := Kubernetes{disablePassHostHeaders: true}
+	actual, err := provider.loadIngresses(client)
+	if err != nil {
+		t.Fatalf("error %+v", err)
+	}
+
+	expected := &types.Configuration{
+		Backends: map[string]*types.Backend{
+			"/bar": {
+				Servers: map[string]types.Server{
+					"1": {
+						URL:    "http://10.0.0.1:801",
+						Weight: 1,
+					},
+				},
+				CircuitBreaker: nil,
+				LoadBalancer:   nil,
+			},
+		},
+		Frontends: map[string]*types.Frontend{
+			"/bar": {
+				Backend: "/bar",
+				Routes: map[string]types.Route{
+					"/bar": {
+						Rule: "PathPrefix:/bar",
+					},
+				},
+			},
+		},
+	}
+	actualJSON, _ := json.Marshal(actual)
+	expectedJSON, _ := json.Marshal(expected)
+
+	if !reflect.DeepEqual(actual, expected) {
+		t.Fatalf("expected %+v, got %+v", string(expectedJSON), string(actualJSON))
+	}
+}
+
 type clientMock struct {
 	ingresses []k8s.Ingress
 	services  []k8s.Service