From a08887040b8a4e4057f3e58166c08b351b5115a3 Mon Sep 17 00:00:00 2001
From: tokers <zchao1995@gmail.com>
Date: Thu, 13 May 2021 15:02:11 +0800
Subject: [PATCH] fix: use exponential backoff mechanism to listen on
 nginx.StatusPort

---
 internal/ingress/controller/checker_test.go   |  3 +-
 internal/ingress/controller/nginx_test.go     | 31 ++++++++++++++++---
 .../metric/collectors/nginx_status_test.go    | 27 +++++++++++++++-
 3 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/internal/ingress/controller/checker_test.go b/internal/ingress/controller/checker_test.go
index 56919dd738..3f02f40165 100644
--- a/internal/ingress/controller/checker_test.go
+++ b/internal/ingress/controller/checker_test.go
@@ -18,7 +18,6 @@ package controller
 
 import (
 	"fmt"
-	"net"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -46,7 +45,7 @@ func TestNginxCheck(t *testing.T) {
 
 			mux := http.NewServeMux()
 
-			listener, err := net.Listen("tcp", fmt.Sprintf(":%v", nginx.StatusPort))
+			listener, err := tryListen("tcp", fmt.Sprintf(":%v", nginx.StatusPort))
 			if err != nil {
 				t.Fatalf("creating tcp listener: %s", err)
 			}
diff --git a/internal/ingress/controller/nginx_test.go b/internal/ingress/controller/nginx_test.go
index cf6463f551..fb86320299 100644
--- a/internal/ingress/controller/nginx_test.go
+++ b/internal/ingress/controller/nginx_test.go
@@ -31,6 +31,7 @@ import (
 
 	jsoniter "github.com/json-iterator/go"
 	apiv1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
 
 	"k8s.io/ingress-nginx/internal/ingress"
 	"k8s.io/ingress-nginx/internal/nginx"
@@ -149,13 +150,13 @@ func TestIsDynamicConfigurationEnough(t *testing.T) {
 }
 
 func TestConfigureDynamically(t *testing.T) {
-	listener, err := net.Listen("tcp", fmt.Sprintf(":%v", nginx.StatusPort))
+	listener, err := tryListen("tcp", fmt.Sprintf(":%v", nginx.StatusPort))
 	if err != nil {
 		t.Fatalf("creating tcp listener: %s", err)
 	}
 	defer listener.Close()
 
-	streamListener, err := net.Listen("tcp", fmt.Sprintf(":%v", nginx.StreamPort))
+	streamListener, err := tryListen("tcp", fmt.Sprintf(":%v", nginx.StreamPort))
 	if err != nil {
 		t.Fatalf("creating tcp listener: %s", err)
 	}
@@ -303,13 +304,13 @@ func TestConfigureDynamically(t *testing.T) {
 }
 
 func TestConfigureCertificates(t *testing.T) {
-	listener, err := net.Listen("tcp", fmt.Sprintf(":%v", nginx.StatusPort))
+	listener, err := tryListen("tcp", fmt.Sprintf(":%v", nginx.StatusPort))
 	if err != nil {
 		t.Fatalf("creating tcp listener: %s", err)
 	}
 	defer listener.Close()
 
-	streamListener, err := net.Listen("tcp", fmt.Sprintf(":%v", nginx.StreamPort))
+	streamListener, err := tryListen("tcp", fmt.Sprintf(":%v", nginx.StreamPort))
 	if err != nil {
 		t.Fatalf("creating tcp listener: %s", err)
 	}
@@ -525,3 +526,25 @@ func TestCleanTempNginxCfg(t *testing.T) {
 		t.Errorf("expected one file but %d were found", len(files))
 	}
 }
+
+func tryListen(network, address string) (l net.Listener, err error) {
+	condFunc := func() (bool, error) {
+		l, err = net.Listen(network, address)
+		if err == nil {
+			return true, nil
+		}
+		if strings.Contains(err.Error(), "bind: address already in use") {
+			return false, nil
+		}
+		return false, err
+	}
+
+	backoff := wait.Backoff{
+		Duration: 500 * time.Millisecond,
+		Factor:   2,
+		Steps:    6,
+		Cap:      128 * time.Second,
+	}
+	err = wait.ExponentialBackoff(backoff, condFunc)
+	return
+}
diff --git a/internal/ingress/metric/collectors/nginx_status_test.go b/internal/ingress/metric/collectors/nginx_status_test.go
index ea9229728a..4dc67c4252 100644
--- a/internal/ingress/metric/collectors/nginx_status_test.go
+++ b/internal/ingress/metric/collectors/nginx_status_test.go
@@ -21,10 +21,13 @@ import (
 	"net"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"k8s.io/apimachinery/pkg/util/wait"
+
 	"k8s.io/ingress-nginx/internal/nginx"
 )
 
@@ -96,7 +99,7 @@ func TestStatusCollector(t *testing.T) {
 
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {
-			listener, err := net.Listen("tcp", fmt.Sprintf(":%v", nginx.StatusPort))
+			listener, err := tryListen("tcp", fmt.Sprintf(":%v", nginx.StatusPort))
 			if err != nil {
 				t.Fatalf("crating unix listener: %s", err)
 			}
@@ -147,3 +150,25 @@ func TestStatusCollector(t *testing.T) {
 		})
 	}
 }
+
+func tryListen(network, address string) (l net.Listener, err error) {
+	condFunc := func() (bool, error) {
+		l, err = net.Listen(network, address)
+		if err == nil {
+			return true, nil
+		}
+		if strings.Contains(err.Error(), "bind: address already in use") {
+			return false, nil
+		}
+		return false, err
+	}
+
+	backoff := wait.Backoff{
+		Duration: 500 * time.Millisecond,
+		Factor:   2,
+		Steps:    6,
+		Cap:      128 * time.Second,
+	}
+	err = wait.ExponentialBackoff(backoff, condFunc)
+	return
+}