do not require --default-backend-service

cmd/nginx/flag_test.go

@@ -31,10 +31,10 @@ func resetForTesting(usage func()) {
 	flag.Usage = usage
 }
 
-func TestMandatoryFlag(t *testing.T) {
+func TestNoMandatoryFlag(t *testing.T) {
 	_, _, err := parseFlags()
-	if err == nil {
-		t.Fatalf("Expected an error about default backend service")
+	if err != nil {
+		t.Fatalf("Expected no error but got: %s", err)
 	}
 }
 

cmd/nginx/flags.go

@@ -176,10 +176,6 @@ Feature backed by OpenResty Lua libraries. Requires that OCSP stapling is not en
 		return true, nil, nil
 	}
 
-	if *defaultSvc == "" {
-		return false, nil, fmt.Errorf("Please specify --default-backend-service")
-	}
-
 	if *ingressClass != "" {
 		glog.Infof("Watching for Ingress class: %s", *ingressClass)
 

cmd/nginx/main.go

@@ -84,20 +84,22 @@ func main() {
 		handleFatalInitError(err)
 	}
 
-	defSvcNs, defSvcName, err := k8s.ParseNameNS(conf.DefaultService)
-	if err != nil {
-		glog.Fatal(err)
-	}
+	if len(conf.DefaultService) > 0 {
+		defSvcNs, defSvcName, err := k8s.ParseNameNS(conf.DefaultService)
+		if err != nil {
+			glog.Fatal(err)
+		}
 
-	_, err = kubeClient.CoreV1().Services(defSvcNs).Get(defSvcName, metav1.GetOptions{})
-	if err != nil {
-		// TODO (antoineco): compare with error types from k8s.io/apimachinery/pkg/api/errors
-		if strings.Contains(err.Error(), "cannot get services in the namespace") {
-			glog.Fatalf("✖ The cluster seems to be running with a restrictive Authorization mode and the Ingress controller does not have the required permissions to operate normally.")
+		_, err = kubeClient.CoreV1().Services(defSvcNs).Get(defSvcName, metav1.GetOptions{})
+		if err != nil {
+			// TODO (antoineco): compare with error types from k8s.io/apimachinery/pkg/api/errors
+			if strings.Contains(err.Error(), "cannot get services in the namespace") {
+				glog.Fatalf("✖ The cluster seems to be running with a restrictive Authorization mode and the Ingress controller does not have the required permissions to operate normally.")
+			}
+			glog.Fatalf("No service with name %v found: %v", conf.DefaultService, err)
 		}
-		glog.Fatalf("No service with name %v found: %v", conf.DefaultService, err)
+		glog.Infof("Validated %v as the default backend.", conf.DefaultService)
 	}
-	glog.Infof("Validated %v as the default backend.", conf.DefaultService)
 
 	if conf.Namespace != "" {
 		_, err = kubeClient.CoreV1().Namespaces().Get(conf.Namespace, metav1.GetOptions{})

deploy/mandatory.yaml

@@ -6,67 +6,6 @@ metadata:
   name: ingress-nginx
 ---
 
-apiVersion: extensions/v1beta1
-kind: Deployment
-metadata:
-  name: default-http-backend
-  labels:
-    app.kubernetes.io/name: default-http-backend
-    app.kubernetes.io/part-of: ingress-nginx
-  namespace: ingress-nginx
-spec:
-  replicas: 1
-  selector:
-    matchLabels:
-      app.kubernetes.io/name: default-http-backend
-      app.kubernetes.io/part-of: ingress-nginx
-  template:
-    metadata:
-      labels:
-        app.kubernetes.io/name: default-http-backend
-        app.kubernetes.io/part-of: ingress-nginx
-    spec:
-      terminationGracePeriodSeconds: 60
-      containers:
-      - name: default-http-backend
-        # Any image is permissible as long as:
-        # 1. It serves a 404 page at /
-        # 2. It serves 200 on a /healthz endpoint
-        image: gcr.io/google_containers/defaultbackend:1.4
-        livenessProbe:
-          httpGet:
-            path: /healthz
-            port: 8080
-            scheme: HTTP
-          initialDelaySeconds: 30
-          timeoutSeconds: 5
-        ports:
-        - containerPort: 8080
-        resources:
-          limits:
-            cpu: 10m
-            memory: 20Mi
-          requests:
-            cpu: 10m
-            memory: 20Mi
----
-
-apiVersion: v1
-kind: Service
-metadata:
-  name: default-http-backend
-  namespace: ingress-nginx
-  labels:
-    app.kubernetes.io/name: default-http-backend
-    app.kubernetes.io/part-of: ingress-nginx
-spec:
-  ports:
-  - port: 80
-    targetPort: 8080
-  selector:
-    app.kubernetes.io/name: default-http-backend
-    app.kubernetes.io/part-of: ingress-nginx
----
 
 kind: ConfigMap
 apiVersion: v1
@@ -277,7 +216,6 @@ spec:
           image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.19.0
           args:
             - /nginx-ingress-controller
-            - --default-backend-service=$(POD_NAMESPACE)/default-http-backend
             - --configmap=$(POD_NAMESPACE)/nginx-configuration
             - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services
             - --udp-services-configmap=$(POD_NAMESPACE)/udp-services

internal/ingress/controller/controller.go

@@ -362,6 +362,12 @@ func (n *NGINXController) getDefaultUpstream() *ingress.Backend {
 		Name: defUpstreamName,
 	}
 	svcKey := n.cfg.DefaultService
+
+	if len(svcKey) == 0 {
+		upstream.Endpoints = append(upstream.Endpoints, n.DefaultEndpoint())
+		return upstream
+	}
+
 	svc, err := n.store.GetService(svcKey)
 	if err != nil {
 		glog.Warningf("Error getting default backend %q: %v", svcKey, err)

rootfs/etc/nginx/template/nginx.tmpl

@@ -584,6 +584,17 @@ http {
 
     {{ end }}
 
+    # backend for when default-backend-service is not configured or it does not have endpoints
+    server {
+        listen {{ $all.ListenPorts.Default }} default_server {{ if $all.Cfg.ReusePort }}reuseport{{ end }} backlog={{ $all.BacklogSize }};
+        {{ if $IsIPV6Enabled }}listen [::]:{{ $all.ListenPorts.Default }} default_server {{ if $all.Cfg.ReusePort }}reuseport{{ end }} backlog={{ $all.BacklogSize }};{{ end }}
+        set $proxy_upstream_name "-";
+
+        location / {
+          return 404;
+        }
+    }
+
     # default server, used for NGINX healthcheck and access to nginx stats
     server {
         listen {{ $all.ListenPorts.Status }} default_server {{ if $all.Cfg.ReusePort }}reuseport{{ end }} backlog={{ $all.BacklogSize }};

test/e2e/annotations/alias.go

@@ -98,7 +98,7 @@ var _ = framework.IngressNginxDescribe("Annotations - Alias", func() {
 
 		Expect(len(errs)).Should(BeNumerically("==", 0))
 		Expect(resp.StatusCode).Should(Equal(http.StatusNotFound))
-		Expect(body).Should(ContainSubstring("default backend - 404"))
+		Expect(body).Should(ContainSubstring("404 Not Found"))
 	})
 
 	It("should return status code 200 for host 'foo' and 'bar'", func() {

test/e2e/defaultbackend/custom_default_backend.go

@@ -0,0 +1,62 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package defaultbackend
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/parnurzeal/gorequest"
+
+	appsv1beta1 "k8s.io/api/apps/v1beta1"
+
+	"k8s.io/ingress-nginx/test/e2e/framework"
+)
+
+var _ = framework.IngressNginxDescribe("Dynamic Certificate", func() {
+	f := framework.NewDefaultFramework("custom-default-backend")
+
+	BeforeEach(func() {
+		err := f.NewEchoDeploymentWithReplicas(1)
+		Expect(err).NotTo(HaveOccurred())
+
+		framework.UpdateDeployment(f.KubeClientSet, f.IngressController.Namespace, "nginx-ingress-controller", 1,
+			func(deployment *appsv1beta1.Deployment) error {
+				args := deployment.Spec.Template.Spec.Containers[0].Args
+				args = append(args, fmt.Sprintf("--default-backend-service=%s/%s", f.IngressController.Namespace, "http-svc"))
+				deployment.Spec.Template.Spec.Containers[0].Args = args
+				_, err := f.KubeClientSet.AppsV1beta1().Deployments(f.IngressController.Namespace).Update(deployment)
+
+				return err
+			})
+
+		err = f.WaitForNginxServer("_",
+			func(server string) bool {
+				return strings.Contains(server, "set $proxy_upstream_name \"upstream-default-backend\"")
+			})
+		Expect(err).ToNot(HaveOccurred())
+	})
+
+	It("uses custom default backend", func() {
+		resp, _, errs := gorequest.New().Get(f.IngressController.HTTPURL).End()
+		Expect(errs).Should(BeEmpty())
+		Expect(resp.StatusCode).Should(Equal(http.StatusOK))
+	})
+})

test/manifests/ingress-controller/mandatory.yaml

@@ -1,65 +1,5 @@
 ---
 
-apiVersion: extensions/v1beta1
-kind: Deployment
-metadata:
-  name: default-http-backend
-  labels:
-    app.kubernetes.io/name: default-http-backend
-    app.kubernetes.io/part-of: ingress-nginx
-spec:
-  replicas: 1
-  selector:
-    matchLabels:
-      app.kubernetes.io/name: default-http-backend
-      app.kubernetes.io/part-of: ingress-nginx
-  template:
-    metadata:
-      labels:
-        app.kubernetes.io/name: default-http-backend
-        app.kubernetes.io/part-of: ingress-nginx
-    spec:
-      terminationGracePeriodSeconds: 60
-      containers:
-      - name: default-http-backend
-        # Any image is permissible as long as:
-        # 1. It serves a 404 page at /
-        # 2. It serves 200 on a /healthz endpoint
-        image: gcr.io/google_containers/defaultbackend:1.4
-        livenessProbe:
-          httpGet:
-            path: /healthz
-            port: 8080
-            scheme: HTTP
-          initialDelaySeconds: 30
-          timeoutSeconds: 5
-        ports:
-        - containerPort: 8080
-        resources:
-          limits:
-            cpu: 10m
-            memory: 20Mi
-          requests:
-            cpu: 10m
-            memory: 20Mi
----
-
-apiVersion: v1
-kind: Service
-metadata:
-  name: default-http-backend
-  labels:
-    app.kubernetes.io/name: default-http-backend
-    app.kubernetes.io/part-of: ingress-nginx
-spec:
-  ports:
-  - port: 80
-    targetPort: 8080
-  selector:
-    app.kubernetes.io/name: default-http-backend
-    app.kubernetes.io/part-of: ingress-nginx
----
-
 kind: ConfigMap
 apiVersion: v1
 metadata:
@@ -275,7 +215,6 @@ spec:
           image: ingress-controller/nginx-ingress-controller:dev
           args:
             - /nginx-ingress-controller
-            - --default-backend-service=$(POD_NAMESPACE)/default-http-backend
             - --configmap=$(POD_NAMESPACE)/nginx-configuration
             - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services
             - --udp-services-configmap=$(POD_NAMESPACE)/udp-services