feat: support enbale nginx debug_connection (#8637)

docs/user-guide/nginx-configuration/configmap.md

@@ -211,6 +211,7 @@ The following table shows a configuration option's name, type, and the default v
 |[global-rate-limit-status-code](#global-rate-limit)|int|429|
 |[service-upstream](#service-upstream)|bool|"false"|
 |[ssl-reject-handshake](#ssl-reject-handshake)|bool|"false"|
+|[debug-connections](#debug-connections)|[]string|"127.0.0.1,1.1.1.1/24"|
 
 ## add-headers
 
@@ -1300,3 +1301,10 @@ _**default:**_ "false"
 
 _References:_
 [https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_reject_handshake](https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_reject_handshake)
+
+## debug-connections
+Enables debugging log for selected client connections.
+_**default:**_ ""
+
+_References:_
+[http://nginx.org/en/docs/ngx_core_module.html#debug_connection](http://nginx.org/en/docs/ngx_core_module.html#debug_connection)

internal/ingress/controller/config/config.go

@@ -768,6 +768,11 @@ type Configuration struct {
 	// GlobalRateLimitStatucCode determines the HTTP status code to return
 	// when limit is exceeding during global rate limiting.
 	GlobalRateLimitStatucCode int `json:"global-rate-limit-status-code"`
+
+	// DebugConnections Enables debugging log for selected client connections
+	// http://nginx.org/en/docs/ngx_core_module.html#debug_connection
+	// Default: ""
+	DebugConnections []string `json:"debug-connections"`
 }
 
 // NewDefault returns the default nginx configuration
@@ -932,6 +937,7 @@ func NewDefault() Configuration {
 		GlobalRateLimitMemcachedMaxIdleTimeout: 10000,
 		GlobalRateLimitMemcachedPoolSize:       50,
 		GlobalRateLimitStatucCode:              429,
+		DebugConnections:                       []string{},
 	}
 
 	if klog.V(5).Enabled() {

internal/ingress/controller/template/configmap.go

@@ -65,6 +65,7 @@ const (
 	globalAuthAlwaysSetCookie     = "global-auth-always-set-cookie"
 	luaSharedDictsKey             = "lua-shared-dicts"
 	plugins                       = "plugins"
+	debugConnections              = "debug-connections"
 )
 
 var (
@@ -111,6 +112,7 @@ func ReadConfig(src map[string]string) config.Configuration {
 	blockRefererList := make([]string, 0)
 	responseHeaders := make([]string, 0)
 	luaSharedDicts := make(map[string]int)
+	debugConnectionsList := make([]string, 0)
 
 	//parse lua shared dict values
 	if val, ok := conf[luaSharedDictsKey]; ok {
@@ -373,6 +375,24 @@ func ReadConfig(src map[string]string) config.Configuration {
 		delete(conf, plugins)
 	}
 
+	if val, ok := conf[debugConnections]; ok {
+		delete(conf, debugConnections)
+		for _, i := range splitAndTrimSpace(val, ",") {
+			validIp := net.ParseIP(i)
+			if validIp != nil {
+				debugConnectionsList = append(debugConnectionsList, i)
+			} else {
+				_, _, err := net.ParseCIDR(i)
+				if err == nil {
+					debugConnectionsList = append(debugConnectionsList, i)
+				} else {
+					klog.Warningf("%v is not a valid IP or CIDR address", i)
+				}
+			}
+		}
+		to.DebugConnections = debugConnectionsList
+	}
+
 	to.CustomHTTPErrors = filterErrors(errors)
 	to.SkipAccessLogURLs = skipUrls
 	to.WhitelistSourceRange = whiteList

internal/ingress/controller/template/configmap_test.go

@@ -75,6 +75,7 @@ func TestMergeConfigMapToStruct(t *testing.T) {
 		"proxy-add-original-uri-header": "false",
 		"disable-ipv6-dns":              "true",
 		"default-type":                  "text/plain",
+		"debug-connections":             "127.0.0.1,1.1.1.1/24,::1",
 	}
 	def := config.NewDefault()
 	def.CustomHTTPErrors = []int{300, 400}
@@ -99,6 +100,7 @@ func TestMergeConfigMapToStruct(t *testing.T) {
 	def.LuaSharedDicts = defaultLuaSharedDicts
 	def.DisableIpv6DNS = true
 	def.DefaultType = "text/plain"
+	def.DebugConnections = []string{"127.0.0.1", "1.1.1.1/24", "::1"}
 
 	hash, err := hashstructure.Hash(def, &hashstructure.HashOptions{
 		TagName: "json",

rootfs/etc/nginx/template/nginx.tmpl

@@ -58,6 +58,9 @@ events {
     multi_accept        {{ if $cfg.EnableMultiAccept }}on{{ else }}off{{ end }};
     worker_connections  {{ $cfg.MaxWorkerConnections }};
     use                 epoll;
+    {{ range $index , $v := $cfg.DebugConnections }}
+    debug_connection    {{ $v }};
+    {{ end }}
 }
 
 http {