Add rejectStatusCode option to IPAllowList middleware

docs/content/middlewares/http/ipallowlist.md

@@ -207,3 +207,45 @@ http:
     [http.middlewares.test-ipallowlist.ipAllowList.ipStrategy]
       excludedIPs = ["127.0.0.1/32", "192.168.1.7"]
 ```
+
+### `rejectStatusCode`
+
+The `rejectStatusCode` option sets HTTP status code for refused requests. If not set, the default is 403 (Forbidden).
+
+```yaml tab="Docker & Swarm"
+# Reject requests with a 404 rather than a 403
+labels:
+    - "traefik.http.middlewares.test-ipallowlist.ipallowlist.rejectstatuscode=404"
+```
+
+```yaml tab="Kubernetes"
+# Reject requests with a 404 rather than a 403
+apiVersion: traefik.io/v1alpha1
+kind: Middleware
+metadata:
+  name: test-ipallowlist
+spec:
+  ipAllowList:
+    rejectStatusCode: 404
+```
+
+```yaml tab="Consul Catalog"
+# Reject requests with a 404 rather than a 403
+- "traefik.http.middlewares.test-ipallowlist.ipallowlist.rejectstatuscode=404"
+```
+
+```yaml tab="File (YAML)"
+# Reject requests with a 404 rather than a 403
+http:
+  middlewares:
+    test-ipallowlist:
+      ipAllowList:
+        rejectStatusCode: 404
+```
+
+```toml tab="File (TOML)"
+# Reject requests with a 404 rather than a 403
+[http.middlewares]
+  [http.middlewares.test-ipallowlist.ipAllowList]
+    rejectStatusCode = 404
+```

docs/content/reference/dynamic-configuration/docker-labels.yml

@@ -68,6 +68,7 @@
 - "traefik.http.middlewares.middleware11.ipallowlist.ipstrategy.depth=42"
 - "traefik.http.middlewares.middleware11.ipallowlist.ipstrategy.excludedips=foobar, foobar"
 - "traefik.http.middlewares.middleware11.ipallowlist.sourcerange=foobar, foobar"
+- "traefik.http.middlewares.middleware11.ipallowlist.rejectstatuscode=404"
 - "traefik.http.middlewares.middleware12.inflightreq.amount=42"
 - "traefik.http.middlewares.middleware12.inflightreq.sourcecriterion.ipstrategy.depth=42"
 - "traefik.http.middlewares.middleware12.inflightreq.sourcecriterion.ipstrategy.excludedips=foobar, foobar"

docs/content/reference/dynamic-configuration/file.toml

@@ -199,6 +199,7 @@
     [http.middlewares.Middleware11]
       [http.middlewares.Middleware11.ipAllowList]
         sourceRange = ["foobar", "foobar"]
+        rejectStatusCode = 404
         [http.middlewares.Middleware11.ipAllowList.ipStrategy]
           depth = 42
           excludedIPs = ["foobar", "foobar"]

docs/content/reference/dynamic-configuration/file.yaml

@@ -225,6 +225,7 @@ http:
         isDevelopment: true
     Middleware11:
       ipAllowList:
+        rejectStatusCode: 404
         sourceRange:
           - foobar
           - foobar

docs/content/reference/dynamic-configuration/kubernetes-crd-definition-v1.yml

@@ -1181,6 +1181,10 @@ spec:
                           type: string
                         type: array
                     type: object
+                  rejectStatusCode:
+                    description: RejectStatusCode defines the HTTP status code used
+                      for refused requests. If not set, the default is 403 (Forbidden).
+                    type: integer
                   sourceRange:
                     description: SourceRange defines the set of allowed IPs (or ranges
                       of allowed IPs by using CIDR notation).

docs/content/reference/dynamic-configuration/kv-ref.md

@@ -81,6 +81,7 @@
 | `traefik/http/middlewares/Middleware11/ipAllowList/ipStrategy/depth` | `42` |
 | `traefik/http/middlewares/Middleware11/ipAllowList/ipStrategy/excludedIPs/0` | `foobar` |
 | `traefik/http/middlewares/Middleware11/ipAllowList/ipStrategy/excludedIPs/1` | `foobar` |
+| `traefik/http/middlewares/Middleware11/ipAllowList/rejectStatusCode` | `404` |
 | `traefik/http/middlewares/Middleware11/ipAllowList/sourceRange/0` | `foobar` |
 | `traefik/http/middlewares/Middleware11/ipAllowList/sourceRange/1` | `foobar` |
 | `traefik/http/middlewares/Middleware12/inFlightReq/amount` | `42` |

docs/content/reference/dynamic-configuration/traefik.io_middlewares.yaml

@@ -606,6 +606,10 @@ spec:
                           type: string
                         type: array
                     type: object
+                  rejectStatusCode:
+                    description: RejectStatusCode defines the HTTP status code used
+                      for refused requests. If not set, the default is 403 (Forbidden).
+                    type: integer
                   sourceRange:
                     description: SourceRange defines the set of allowed IPs (or ranges
                       of allowed IPs by using CIDR notation).

integration/fixtures/k8s/01-traefik-crd.yml

@@ -1181,6 +1181,10 @@ spec:
                           type: string
                         type: array
                     type: object
+                  rejectStatusCode:
+                    description: RejectStatusCode defines the HTTP status code used
+                      for refused requests. If not set, the default is 403 (Forbidden).
+                    type: integer
                   sourceRange:
                     description: SourceRange defines the set of allowed IPs (or ranges
                       of allowed IPs by using CIDR notation).

pkg/config/dynamic/middlewares.go

@@ -383,6 +383,9 @@ type IPAllowList struct {
 	// SourceRange defines the set of allowed IPs (or ranges of allowed IPs by using CIDR notation).
 	SourceRange []string    `json:"sourceRange,omitempty" toml:"sourceRange,omitempty" yaml:"sourceRange,omitempty"`
 	IPStrategy  *IPStrategy `json:"ipStrategy,omitempty" toml:"ipStrategy,omitempty" yaml:"ipStrategy,omitempty" label:"allowEmpty" file:"allowEmpty" kv:"allowEmpty" export:"true"`
+	// RejectStatusCode defines the HTTP status code used for refused requests.
+	// If not set, the default is 403 (Forbidden).
+	RejectStatusCode int `json:"rejectStatusCode,omitempty" toml:"rejectStatusCode,omitempty" yaml:"rejectStatusCode,omitempty" label:"allowEmpty" file:"allowEmpty" kv:"allowEmpty" export:"true"`
 }
 
 // +k8s:deepcopy-gen=true

pkg/config/label/label_test.go

@@ -1254,6 +1254,7 @@ func TestEncodeConfiguration(t *testing.T) {
 		"traefik.HTTP.Middlewares.Middleware8.Headers.STSSeconds":                                  "42",
 		"traefik.HTTP.Middlewares.Middleware9.IPAllowList.IPStrategy.Depth":                        "42",
 		"traefik.HTTP.Middlewares.Middleware9.IPAllowList.IPStrategy.ExcludedIPs":                  "foobar, fiibar",
+		"traefik.HTTP.Middlewares.Middleware9.IPAllowList.RejectStatusCode":                        "0",
 		"traefik.HTTP.Middlewares.Middleware9.IPAllowList.SourceRange":                             "foobar, fiibar",
 		"traefik.HTTP.Middlewares.Middleware10.InFlightReq.Amount":                                 "42",
 		"traefik.HTTP.Middlewares.Middleware10.InFlightReq.SourceCriterion.IPStrategy.Depth":       "42",

pkg/middlewares/ipallowlist/ip_allowlist.go

@@ -20,10 +20,11 @@ const (
 
 // ipAllowLister is a middleware that provides Checks of the Requesting IP against a set of Allowlists.
 type ipAllowLister struct {
-	next        http.Handler
+	next             http.Handler
-	allowLister *ip.Checker
+	allowLister      *ip.Checker
-	strategy    ip.Strategy
+	strategy         ip.Strategy
-	name        string
+	name             string
+	rejectStatusCode int
 }
 
 // New builds a new IPAllowLister given a list of CIDR-Strings to allow.
@@ -35,6 +36,14 @@ func New(ctx context.Context, next http.Handler, config dynamic.IPAllowList, nam
 		return nil, errors.New("sourceRange is empty, IPAllowLister not created")
 	}
 
+	rejectStatusCode := config.RejectStatusCode
+	// If RejectStatusCode is not given, default to Forbidden (403).
+	if rejectStatusCode == 0 {
+		rejectStatusCode = http.StatusForbidden
+	} else if http.StatusText(rejectStatusCode) == "" {
+		return nil, fmt.Errorf("invalid HTTP status code %d", rejectStatusCode)
+	}
+
 	checker, err := ip.NewChecker(config.SourceRange)
 	if err != nil {
 		return nil, fmt.Errorf("cannot parse CIDRs %s: %w", config.SourceRange, err)
@@ -48,10 +57,11 @@ func New(ctx context.Context, next http.Handler, config dynamic.IPAllowList, nam
 	logger.Debug().Msgf("Setting up IPAllowLister with sourceRange: %s", config.SourceRange)
 
 	return &ipAllowLister{
-		strategy:    strategy,
+		strategy:         strategy,
-		allowLister: checker,
+		allowLister:      checker,
-		next:        next,
+		next:             next,
-		name:        name,
+		name:             name,
+		rejectStatusCode: rejectStatusCode,
 	}, nil
 }
 
@@ -69,7 +79,7 @@ func (al *ipAllowLister) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		msg := fmt.Sprintf("Rejecting IP %s: %v", clientIP, err)
 		logger.Debug().Msg(msg)
 		tracing.SetStatusErrorf(req.Context(), msg)
-		reject(ctx, rw)
+		reject(ctx, al.rejectStatusCode, rw)
 		return
 	}
 	logger.Debug().Msgf("Accepting IP %s", clientIP)
@@ -77,9 +87,7 @@ func (al *ipAllowLister) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	al.next.ServeHTTP(rw, req)
 }
 
-func reject(ctx context.Context, rw http.ResponseWriter) {
+func reject(ctx context.Context, statusCode int, rw http.ResponseWriter) {
-	statusCode := http.StatusForbidden
-
 	rw.WriteHeader(statusCode)
 	_, err := rw.Write([]byte(http.StatusText(statusCode)))
 	if err != nil {

pkg/middlewares/ipallowlist/ip_allowlist_test.go

@@ -30,6 +30,14 @@ func TestNewIPAllowLister(t *testing.T) {
 				SourceRange: []string{"10.10.10.10"},
 			},
 		},
+		{
+			desc: "invalid HTTP status code",
+			allowList: dynamic.IPAllowList{
+				SourceRange:      []string{"10.10.10.10"},
+				RejectStatusCode: 600,
+			},
+			expectedError: true,
+		},
 	}
 
 	for _, test := range testCases {
@@ -73,6 +81,24 @@ func TestIPAllowLister_ServeHTTP(t *testing.T) {
 			remoteAddr: "20.20.20.21:1234",
 			expected:   403,
 		},
+		{
+			desc: "authorized with remote address, reject 404",
+			allowList: dynamic.IPAllowList{
+				SourceRange:      []string{"20.20.20.20"},
+				RejectStatusCode: 404,
+			},
+			remoteAddr: "20.20.20.20:1234",
+			expected:   200,
+		},
+		{
+			desc: "non authorized with remote address, reject 404",
+			allowList: dynamic.IPAllowList{
+				SourceRange:      []string{"20.20.20.20"},
+				RejectStatusCode: 404,
+			},
+			remoteAddr: "20.20.20.21:1234",
+			expected:   404,
+		},
 	}
 
 	for _, test := range testCases {