Managing a whitelist for _/nginx_status (#2187)

Signed-off-by: Sylvain Rabot <s.rabot@lectra.com>

docs/user-guide/configmap.md

@@ -63,6 +63,8 @@ The following table shows a configuration option's name, type, and the default v
 |[log-format-stream](#log-format-stream)|string|`[$time_local] $protocol $status $bytes_sent $bytes_received $session_time`|
 |[max-worker-connections](#max-worker-connections)|int|16384|
 |[map-hash-bucket-size](#max-worker-connections)|int|64|
+|[nginx-status-ipv4-whitelist](#nginx-status-ipv4-whitelist)|[]string|"127.0.0.1"|
+|[nginx-status-ipv6-whitelist](#nginx-status-ipv6-whitelist)|[]string|"::1"|
 |[proxy-real-ip-cidr](#proxy-real-ip-cidr)|[]string|"0.0.0.0/0"|
 |[proxy-set-headers](#proxy-set-headers)|string|""|
 |[server-name-hash-max-size](#server-name-hash-max-size)|int|1024|

internal/ingress/controller/config/config.go

@@ -250,6 +250,11 @@ type Configuration struct {
 	// http://nginx.org/en/docs/http/ngx_http_map_module.html#map_hash_bucket_size
 	MapHashBucketSize int `json:"map-hash-bucket-size,omitempty"`
 
+	// NginxStatusIpv4Whitelist has the list of cidr that are allowed to access
+	// the /nginx_status endpoint of the "_" server
+	NginxStatusIpv4Whitelist []string `json:"nginx-status-ipv4-whitelist,omitempty"`
+	NginxStatusIpv6Whitelist []string `json:"nginx-status-ipv6-whitelist,omitempty"`
+
 	// If UseProxyProtocol is enabled ProxyRealIPCIDR defines the default the IP/network address
 	// of your external load balancer
 	ProxyRealIPCIDR []string `json:"proxy-real-ip-cidr,omitempty"`
@@ -499,8 +504,14 @@ type Configuration struct {
 // NewDefault returns the default nginx configuration
 func NewDefault() Configuration {
 	defIPCIDR := make([]string, 0)
-	defIPCIDR = append(defIPCIDR, "0.0.0.0/0")
 	defBindAddress := make([]string, 0)
+	defNginxStatusIpv4Whitelist := make([]string, 0)
+	defNginxStatusIpv6Whitelist := make([]string, 0)
+
+	defIPCIDR = append(defIPCIDR, "0.0.0.0/0")
+	defNginxStatusIpv4Whitelist = append(defNginxStatusIpv4Whitelist, "127.0.0.1")
+	defNginxStatusIpv6Whitelist = append(defNginxStatusIpv6Whitelist, "::1")
+
 	cfg := Configuration{
 		AllowBackendServerHeader:   false,
 		AccessLogPath:              "/var/log/nginx/access.log",
@@ -534,6 +545,8 @@ func NewDefault() Configuration {
 		LogFormatUpstream:          logFormatUpstream,
 		MaxWorkerConnections:       16384,
 		MapHashBucketSize:          64,
+		NginxStatusIpv4Whitelist:   defNginxStatusIpv4Whitelist,
+		NginxStatusIpv6Whitelist:   defNginxStatusIpv6Whitelist,
 		ProxyRealIPCIDR:            defIPCIDR,
 		ServerNameHashMaxSize:      1024,
 		ProxyHeadersHashMaxSize:    512,
@@ -629,6 +642,8 @@ type TemplateConfig struct {
 	Cfg                         Configuration
 	IsIPV6Enabled               bool
 	IsSSLPassthroughEnabled     bool
+	NginxStatusIpv4Whitelist    []string
+	NginxStatusIpv6Whitelist    []string
 	RedirectServers             map[string]string
 	ListenPorts                 *ListenPorts
 	PublishService              *apiv1.Service

internal/ingress/controller/nginx.go

@@ -621,6 +621,8 @@ func (n *NGINXController) OnUpdate(ingressCfg ingress.Configuration) error {
 		CustomErrors:                len(cfg.CustomHTTPErrors) > 0,
 		Cfg:                         cfg,
 		IsIPV6Enabled:               n.isIPV6Enabled && !cfg.DisableIpv6,
+		NginxStatusIpv4Whitelist:    cfg.NginxStatusIpv4Whitelist,
+		NginxStatusIpv6Whitelist:    cfg.NginxStatusIpv6Whitelist,
 		RedirectServers:             redirectServers,
 		IsSSLPassthroughEnabled:     n.cfg.EnableSSLPassthrough,
 		ListenPorts:                 n.cfg.ListenPorts,

internal/ingress/controller/template/configmap.go

@@ -32,14 +32,16 @@ import (
 )
 
 const (
-	customHTTPErrors     = "custom-http-errors"
-	skipAccessLogUrls    = "skip-access-log-urls"
-	whitelistSourceRange = "whitelist-source-range"
-	proxyRealIPCIDR      = "proxy-real-ip-cidr"
-	bindAddress          = "bind-address"
-	httpRedirectCode     = "http-redirect-code"
-	proxyStreamResponses = "proxy-stream-responses"
-	hideHeaders          = "hide-headers"
+	customHTTPErrors         = "custom-http-errors"
+	skipAccessLogUrls        = "skip-access-log-urls"
+	whitelistSourceRange     = "whitelist-source-range"
+	proxyRealIPCIDR          = "proxy-real-ip-cidr"
+	bindAddress              = "bind-address"
+	httpRedirectCode         = "http-redirect-code"
+	proxyStreamResponses     = "proxy-stream-responses"
+	hideHeaders              = "hide-headers"
+	nginxStatusIpv4Whitelist = "nginx-status-ipv4-whitelist"
+	nginxStatusIpv6Whitelist = "nginx-status-ipv6-whitelist"
 )
 
 var (
@@ -54,6 +56,7 @@ func ReadConfig(src map[string]string) config.Configuration {
 		conf[k] = v
 	}
 
+	to := config.NewDefault()
 	errors := make([]int, 0)
 	skipUrls := make([]string, 0)
 	whiteList := make([]string, 0)
@@ -62,7 +65,6 @@ func ReadConfig(src map[string]string) config.Configuration {
 
 	bindAddressIpv4List := make([]string, 0)
 	bindAddressIpv6List := make([]string, 0)
-	redirectCode := 308
 
 	if val, ok := conf[customHTTPErrors]; ok {
 		delete(conf, customHTTPErrors)
@@ -116,7 +118,7 @@ func ReadConfig(src map[string]string) config.Configuration {
 			glog.Warningf("%v is not a valid HTTP code: %v", val, err)
 		} else {
 			if validRedirectCodes.Has(j) {
-				redirectCode = j
+				to.HTTPRedirectCode = j
 			} else {
 				glog.Warningf("The code %v is not a valid as HTTP redirect code. Using the default.", val)
 			}
@@ -134,7 +136,22 @@ func ReadConfig(src map[string]string) config.Configuration {
 		}
 	}
 
-	to := config.NewDefault()
+	// Nginx Status whitlelist
+	if val, ok := conf[nginxStatusIpv4Whitelist]; ok {
+		whitelist := make([]string, 0)
+		whitelist = append(whitelist, strings.Split(val, ",")...)
+		to.NginxStatusIpv4Whitelist = whitelist
+
+		delete(conf, nginxStatusIpv4Whitelist)
+	}
+	if val, ok := conf[nginxStatusIpv6Whitelist]; ok {
+		whitelist := make([]string, 0)
+		whitelist = append(whitelist, strings.Split(val, ",")...)
+		to.NginxStatusIpv6Whitelist = whitelist
+
+		delete(conf, nginxStatusIpv6Whitelist)
+	}
+
 	to.CustomHTTPErrors = filterErrors(errors)
 	to.SkipAccessLogURLs = skipUrls
 	to.WhitelistSourceRange = whiteList
@@ -142,7 +159,6 @@ func ReadConfig(src map[string]string) config.Configuration {
 	to.BindAddressIpv4 = bindAddressIpv4List
 	to.BindAddressIpv6 = bindAddressIpv6List
 	to.HideHeaders = hideHeadersList
-	to.HTTPRedirectCode = redirectCode
 	to.ProxyStreamResponses = streamResponses
 	to.DisableIpv6DNS = !ing_net.IsIPv6Enabled()
 

internal/ingress/controller/template/configmap_test.go

@@ -33,20 +33,22 @@ func TestFilterErrors(t *testing.T) {
 
 func TestMergeConfigMapToStruct(t *testing.T) {
 	conf := map[string]string{
-		"custom-http-errors":         "300,400,demo",
-		"proxy-read-timeout":         "1",
-		"proxy-send-timeout":         "2",
-		"skip-access-log-urls":       "/log,/demo,/test",
-		"use-proxy-protocol":         "true",
-		"disable-access-log":         "true",
-		"access-log-path":            "/var/log/test/access.log",
-		"error-log-path":             "/var/log/test/error.log",
-		"use-gzip":                   "true",
-		"enable-dynamic-tls-records": "false",
-		"gzip-types":                 "text/html",
-		"proxy-real-ip-cidr":         "1.1.1.1/8,2.2.2.2/24",
-		"bind-address":               "1.1.1.1,2.2.2.2,3.3.3,2001:db8:a0b:12f0::1,3731:54:65fe:2::a7,33:33:33::33::33",
-		"worker-shutdown-timeout":    "99s",
+		"custom-http-errors":          "300,400,demo",
+		"proxy-read-timeout":          "1",
+		"proxy-send-timeout":          "2",
+		"skip-access-log-urls":        "/log,/demo,/test",
+		"use-proxy-protocol":          "true",
+		"disable-access-log":          "true",
+		"access-log-path":             "/var/log/test/access.log",
+		"error-log-path":              "/var/log/test/error.log",
+		"use-gzip":                    "true",
+		"enable-dynamic-tls-records":  "false",
+		"gzip-types":                  "text/html",
+		"proxy-real-ip-cidr":          "1.1.1.1/8,2.2.2.2/24",
+		"bind-address":                "1.1.1.1,2.2.2.2,3.3.3,2001:db8:a0b:12f0::1,3731:54:65fe:2::a7,33:33:33::33::33",
+		"worker-shutdown-timeout":     "99s",
+		"nginx-status-ipv4-whitelist": "127.0.0.1,10.0.0.0/24",
+		"nginx-status-ipv6-whitelist": "::1,2001::/16",
 	}
 	def := config.NewDefault()
 	def.CustomHTTPErrors = []int{300, 400}
@@ -63,6 +65,8 @@ func TestMergeConfigMapToStruct(t *testing.T) {
 	def.BindAddressIpv4 = []string{"1.1.1.1", "2.2.2.2"}
 	def.BindAddressIpv6 = []string{"[2001:db8:a0b:12f0::1]", "[3731:54:65fe:2::a7]"}
 	def.WorkerShutdownTimeout = "99s"
+	def.NginxStatusIpv4Whitelist = []string{"127.0.0.1", "10.0.0.0/24"}
+	def.NginxStatusIpv6Whitelist = []string{"::1", "2001::/16"}
 
 	to := ReadConfig(conf)
 	if diff := pretty.Compare(to, def); diff != "" {

rootfs/etc/nginx/template/nginx.tmpl

@@ -1011,8 +1011,14 @@ stream {
         # this is required to avoid error if nginx is being monitored
         # with an external software (like sysdig)
         location /nginx_status {
-            allow 127.0.0.1;
-            {{ if $all.IsIPV6Enabled }}allow ::1;{{ end }}
+            {{ range $v := $all.NginxStatusIpv4Whitelist }}
+            allow {{ $v }};
+            {{ end }}
+            {{ if $all.IsIPV6Enabled -}}
+            {{ range $v := $all.NginxStatusIpv6Whitelist }}
+            allow {{ $v }};
+            {{ end }}
+            {{ end -}}
             deny all;
 
             access_log off;

test/data/config.json

@@ -26,6 +26,8 @@
 		"keepAlive": 75,
 		"mapHashBucketSize": 64,
 		"maxWorkerConnections": 16384,
+		"nginxStatusIpv4Whitelist": "127.0.0.1",
+		"nginxStatusIpv6Whitelist": "::1",
 		"proxyRealIpCidr": "0.0.0.0/0",
 		"retryNonIdempotent": false,
 		"serverNameHashBucketSize": 64,
@@ -113,7 +115,7 @@
 				"pemSha": ""
 			},
 			"vtsDefaultFilterKey": "$uri $server_name"
-			
+
 		}, {
 			"path": "/",
 			"isDefBackend": true,
@@ -57210,4 +57212,4 @@
 			"failTimeout": 0
 		}]
 	}]
-}
+}