Update lua configuration_data when number of controller pod change

internal/ingress/controller/controller.go

@@ -163,6 +163,7 @@ func (n *NGINXController) syncIngress(interface{}) error {
 		UDPEndpoints:          n.getStreamServices(n.cfg.UDPConfigMapName, apiv1.ProtocolUDP),
 		PassthroughBackends:   passUpstreams,
 		BackendConfigChecksum: n.store.GetBackendConfiguration().Checksum,
+		ControllerPodsCount:   n.store.GetRunningControllerPodsCount(),
 	}
 
 	if n.runningConfig.Equal(pcfg) {

internal/ingress/controller/nginx.go

@@ -752,6 +752,8 @@ func (n *NGINXController) IsDynamicConfigurationEnough(pcfg *ingress.Configurati
 
 	copyOfRunningConfig.Backends = []*ingress.Backend{}
 	copyOfPcfg.Backends = []*ingress.Backend{}
+	copyOfRunningConfig.ControllerPodsCount = 0
+	copyOfPcfg.ControllerPodsCount = 0
 
 	if n.cfg.DynamicCertificatesEnabled {
 		clearCertificates(&copyOfRunningConfig)
@@ -825,6 +827,14 @@ func configureDynamically(pcfg *ingress.Configuration, port int, isDynamicCertif
 		return err
 	}
 
+	url = fmt.Sprintf("http://localhost:%d/configuration/general", port)
+	err = post(url, &ingress.GeneralConfig{
+		ControllerPodsCount: pcfg.ControllerPodsCount,
+	})
+	if err != nil {
+		return err
+	}
+
 	if isDynamicCertificatesEnabled {
 		err = configureCertificates(pcfg, port)
 		if err != nil {

internal/ingress/controller/nginx_test.go

@@ -205,8 +205,9 @@ func TestConfigureDynamically(t *testing.T) {
 	}}
 
 	commonConfig := &ingress.Configuration{
-		Backends: backends,
-		Servers:  servers,
+		Backends:            backends,
+		Servers:             servers,
+		ControllerPodsCount: 2,
 	}
 
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -221,12 +222,26 @@ func TestConfigureDynamically(t *testing.T) {
 			t.Fatal(err)
 		}
 		body := string(b)
-		if strings.Contains(body, "target") {
-			t.Errorf("unexpected target reference in JSON content: %v", body)
-		}
 
-		if !strings.Contains(body, "service") {
-			t.Errorf("service reference should be present in JSON content: %v", body)
+		switch r.URL.Path {
+		case "/configuration/backends":
+			{
+				if strings.Contains(body, "target") {
+					t.Errorf("unexpected target reference in JSON content: %v", body)
+				}
+
+				if !strings.Contains(body, "service") {
+					t.Errorf("service reference should be present in JSON content: %v", body)
+				}
+			}
+		case "/configuration/general":
+			{
+				if !strings.Contains(body, "controllerPodsCount") {
+					t.Errorf("controllerPodsCount should be present in JSON content: %v", body)
+				}
+			}
+		default:
+			t.Errorf("unknown request to %s", r.URL.Path)
 		}
 
 	}))

internal/ingress/controller/store/store.go

@@ -76,8 +76,8 @@ type Storer interface {
 	// ListIngresses returns a list of all Ingresses in the store.
 	ListIngresses() []*ingress.Ingress
 
-	// ListControllerPods returns a list of ingress-nginx controller Pods.
-	ListControllerPods() []*corev1.Pod
+	// GetRunningControllerPodsCount returns the number of Running ingress-nginx controller Pods.
+	GetRunningControllerPodsCount() int
 
 	// GetLocalSSLCert returns the local copy of a SSLCert
 	GetLocalSSLCert(name string) (*ingress.SSLCert, error)
@@ -288,12 +288,10 @@ func New(checkOCSP bool,
 	store.informers.Pod = cache.NewSharedIndexInformer(
 		&cache.ListWatch{
 			ListFunc: func(options metav1.ListOptions) (k8sruntime.Object, error) {
-
 				options.LabelSelector = labelSelector.String()
 				return client.CoreV1().Pods(store.pod.Namespace).List(options)
 			},
 			WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
-
 				options.LabelSelector = labelSelector.String()
 				return client.CoreV1().Pods(store.pod.Namespace).Watch(options)
 			},
@@ -832,9 +830,9 @@ func (s *k8sStore) Run(stopCh chan struct{}) {
 	}
 }
 
-// ListControllerPods returns a list of ingress-nginx controller Pods
-func (s *k8sStore) ListControllerPods() []*corev1.Pod {
-	var pods []*corev1.Pod
+// GetRunningControllerPodsCount returns the number of Running ingress-nginx controller Pods
+func (s k8sStore) GetRunningControllerPodsCount() int {
+	count := 0
 
 	for _, i := range s.listers.Pod.List() {
 		pod := i.(*corev1.Pod)
@@ -843,8 +841,8 @@ func (s *k8sStore) ListControllerPods() []*corev1.Pod {
 			continue
 		}
 
-		pods = append(pods, pod)
+		count++
 	}
 
-	return pods
+	return count
 }

internal/ingress/controller/store/store_test.go

@@ -1062,7 +1062,7 @@ func TestWriteSSLSessionTicketKey(t *testing.T) {
 	}
 }
 
-func TestListControllerPods(t *testing.T) {
+func TestGetRunningControllerPodsCount(t *testing.T) {
 	os.Setenv("POD_NAMESPACE", "testns")
 	os.Setenv("POD_NAME", "ingress-1")
 
@@ -1117,8 +1117,8 @@ func TestListControllerPods(t *testing.T) {
 	}
 	s.listers.Pod.Add(pod)
 
-	pods := s.ListControllerPods()
-	if s := len(pods); s != 2 {
+	podsCount := s.GetRunningControllerPodsCount()
+	if podsCount != 2 {
 		t.Errorf("Expected 1 controller Pods but got %v", s)
 	}
 }

internal/ingress/types.go

@@ -71,6 +71,9 @@ type Configuration struct {
 
 	// ConfigurationChecksum contains the particular checksum of a Configuration object
 	ConfigurationChecksum string `json:"configurationChecksum,omitempty"`
+
+	// ControllerPodsCount contains the list of running ingress controller Pod(s)
+	ControllerPodsCount int `json:"controllerPodsCount,omitempty"`
 }
 
 // Backend describes one or more remote server/s (endpoints) associated with a service
@@ -338,3 +341,8 @@ type Ingress struct {
 	extensions.Ingress
 	ParsedAnnotations *annotations.Ingress
 }
+
+// GeneralConfig holds the definition of lua general configuration data
+type GeneralConfig struct {
+	ControllerPodsCount int `json:"controllerPodsCount"`
+}

internal/ingress/types_equals.go

@@ -105,6 +105,10 @@ func (c1 *Configuration) Equal(c2 *Configuration) bool {
 		return false
 	}
 
+	if c1.ControllerPodsCount != c2.ControllerPodsCount {
+		return false
+	}
+
 	return true
 }
 

rootfs/etc/nginx/lua/configuration.lua

@@ -12,6 +12,10 @@ function _M.get_backends_data()
   return configuration_data:get("backends")
 end
 
+function _M.get_general_data()
+  return configuration_data:get("general")
+end
+
 local function fetch_request_body()
   ngx.req.read_body()
   local body = ngx.req.get_body_data()
@@ -80,6 +84,31 @@ local function handle_servers()
   ngx.status = ngx.HTTP_CREATED
 end
 
+local function handle_general()
+  if ngx.var.request_method == "GET" then
+    ngx.status = ngx.HTTP_OK
+    ngx.print(_M.get_general_data())
+    return
+  end
+
+  if ngx.var.request_method ~= "POST" then
+    ngx.status = ngx.HTTP_BAD_REQUEST
+    ngx.print("Only POST and GET requests are allowed!")
+    return
+  end
+
+  local config = fetch_request_body()
+
+  local success, err = configuration_data:safe_set("general", config)
+  if not success then
+    ngx.status = ngx.HTTP_INTERNAL_SERVER_ERROR
+    ngx.log(ngx.ERR, "error setting general config: " .. tostring(err))
+    return
+  end
+
+  ngx.status = ngx.HTTP_CREATED
+end
+
 function _M.call()
   if ngx.var.request_method ~= "POST" and ngx.var.request_method ~= "GET" then
     ngx.status = ngx.HTTP_BAD_REQUEST
@@ -92,6 +121,11 @@ function _M.call()
     return
   end
 
+  if ngx.var.request_uri == "/configuration/general" then
+    handle_general()
+    return
+  end
+
   if ngx.var.request_uri ~= "/configuration/backends" then
     ngx.status = ngx.HTTP_NOT_FOUND
     ngx.print("Not found!")

test/e2e/framework/exec.go

@@ -28,6 +28,16 @@ import (
 	"k8s.io/api/core/v1"
 )
 
+// ExecIngressPod executes a command inside the first container in ingress controller running pod
+func (f *Framework) ExecIngressPod(command string) (string, error) {
+	pod, err := getIngressNGINXPod(f.IngressController.Namespace, f.KubeClientSet)
+	if err != nil {
+		return "", err
+	}
+
+	return f.ExecCommand(pod, command)
+}
+
 // ExecCommand executes a command inside a the first container in a running pod
 func (f *Framework) ExecCommand(pod *v1.Pod, command string) (string, error) {
 	var (

test/e2e/lua/dynamic_configuration.go

@@ -149,6 +149,20 @@ var _ = framework.IngressNginxDescribe("Dynamic Configuration", func() {
 		})
 		Expect(nginxConfig).ShouldNot(Equal(newNginxConfig))
 	})
+
+	It("sets controllerPodsCount in Lua general configuration", func() {
+		output, err := f.ExecIngressPod("curl --fail --silent http://127.0.0.1:18080/configuration/general")
+		Expect(err).ToNot(HaveOccurred())
+		Expect(output).Should(Equal(`{"controllerPodsCount":1}`))
+
+		err = framework.UpdateDeployment(f.KubeClientSet, f.IngressController.Namespace, "nginx-ingress-controller", 3, nil)
+		Expect(err).ToNot(HaveOccurred())
+		time.Sleep(waitForLuaSync)
+
+		output, err = f.ExecIngressPod("curl --fail --silent http://127.0.0.1:18080/configuration/general")
+		Expect(err).ToNot(HaveOccurred())
+		Expect(output).Should(Equal(`{"controllerPodsCount":3}`))
+	})
 })
 
 func ensureIngress(f *framework.Framework, host string) *extensions.Ingress {