Merge current v2.11 into v3.6

.github/workflows/validate.yaml

@@ -7,7 +7,7 @@ on:
 
 env:
   GO_VERSION: '1.24'
-  GOLANGCI_LINT_VERSION: v2.0.2
+  GOLANGCI_LINT_VERSION: v2.8.0
   MISSPELL_VERSION: v0.7.0
 
 jobs:

.golangci.yml

@@ -36,6 +36,7 @@ linters:
     - nilnil # Not relevant
     - nlreturn # Not relevant
     - noctx # Too strict
+    - noinlineerr # Too strict
     - nonamedreturns # Too strict
     - paralleltest # Not relevant
     - prealloc # Too many false-positive.
@@ -47,6 +48,7 @@ linters:
     - varnamelen # Not relevant
     - wrapcheck # Too strict
     - wsl # Too strict
+    - wsl_v5 # Too strict
 
   settings:
     depguard:
@@ -295,15 +297,31 @@ linters:
         source: 'errors.New\("Nomad provider'
         text: 'ST1005: error strings should not be capitalized'
       - path: (.+)\.go
-        text: 'struct-tag: unknown option ''inline'' in JSON tag'
+        text: 'omitzero: Omitempty has no effect on nested struct field'
+        linters:
+          - modernize
+      - path: (.+)\.go
+        text: 'struct-tag: unknown option "inline" in json tag'
         linters:
           - revive
       - path: (.+)\.go
-        text: 'struct-tag: unknown option ''omitzero'' in TOML tag'
+        text: 'struct-tag: unknown option "omitzero" in toml tag'
+        linters:
+          - revive
+      - path: (pkg/types/.+|pkg/api/.+|pkg/observability/types/.+)\.go
+        text: 'var-naming: avoid meaningless package names'
+        linters:
+          - revive
+      - path: (pkg/muxer/http/.+|pkg/provider/http/.+)\.go
+        text: 'var-naming: avoid package names that conflict with Go standard library package names'
         linters:
           - revive
       - path: (.+)\.go$
         text: 'SA1019: http.CloseNotifier has been deprecated' # FIXME must be fixed
+      - path: (.+)\.go$
+        text: 'SA1019: dynamic.(TCPIPWhiteList|IPWhiteList) is deprecated: please use IPAllowList instead.'
+      - path: (.+)\.go$
+        text: 'SA1019: middlewareTCP.Spec.IPWhiteList is deprecated: please use IPAllowList instead.'
       - path: (.+)\.go$
         text: 'SA1019: cfg.(SSLRedirect|SSLTemporaryRedirect|SSLHost|SSLForceHost|FeaturePolicy) is deprecated'
       - path: (.+)\.go$

cmd/configuration.go

@@ -10,6 +10,7 @@ import (
 // TraefikCmdConfiguration wraps the static configuration and extra parameters.
 type TraefikCmdConfiguration struct {
 	static.Configuration `export:"true"`
+
 	// ConfigFile is the path to the configuration file.
 	ConfigFile string `description:"Configuration file to use. If specified all other flags are ignored." export:"true"`
 }

cmd/internal/gen/main.go

@@ -83,7 +83,7 @@ func run(dest string) error {
 		return err
 	}
 
-	return os.WriteFile(filepath.Join(dest, "marshaler.go"), []byte(fmt.Sprintf(marsh, destPkg)), 0o666)
+	return os.WriteFile(filepath.Join(dest, "marshaler.go"), fmt.Appendf(nil, marsh, destPkg), 0o666)
 }
 
 func cleanType(typ types.Type, base string) string {

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

@@ -373,6 +373,7 @@ spec:
                       description: |-
                         Syntax defines the router's rule syntax.
                         More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/http/routing/rules-and-priority/#rulesyntax
+
                         Deprecated: Please do not use this field and rewrite the router rules to use the v3 syntax.
                       type: string
                   required:
@@ -584,6 +585,7 @@ spec:
                             description: |-
                               ProxyProtocol defines the PROXY protocol configuration.
                               More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/tcp/service/#proxy-protocol
+
                               Deprecated: ProxyProtocol will not be supported in future APIVersions, please use ServersTransport to configure ProxyProtocol instead.
                             properties:
                               version:
@@ -606,6 +608,7 @@ spec:
                               hence fully terminating the connection.
                               It is a duration in milliseconds, defaulting to 100.
                               A negative value means an infinite deadline (i.e. the reading capability is never closed).
+
                               Deprecated: TerminationDelay will not be supported in future APIVersions, please use ServersTransport to configure the TerminationDelay instead.
                             type: integer
                           tls:
@@ -626,6 +629,7 @@ spec:
                       description: |-
                         Syntax defines the router's rule syntax.
                         More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/tcp/routing/rules-and-priority/#rulesyntax
+
                         Deprecated: Please do not use this field and rewrite the router rules to use the v3 syntax.
                       enum:
                       - v3
@@ -1060,6 +1064,7 @@ spec:
                     description: |-
                       AutoDetect specifies whether to let the `Content-Type` header, if it has not been set by the backend,
                       be automatically set to a value derived from the contents of the response.
+
                       Deprecated: AutoDetect option is deprecated, Content-Type middleware is only meant to be used to enable the content-type detection, please remove any usage of this option.
                     type: boolean
                 type: object
@@ -2212,8 +2217,9 @@ spec:
                 description: |-
                   IPWhiteList defines the IPWhiteList middleware configuration.
                   This middleware accepts/refuses connections based on the client IP.
-                  Deprecated: please use IPAllowList instead.
                   More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/tcp/middlewares/ipwhitelist/
+
+                  Deprecated: please use IPAllowList instead.
                 properties:
                   sourceRange:
                     description: SourceRange defines the allowed IPs (or ranges of
@@ -2370,6 +2376,7 @@ spec:
               rootCAsSecrets:
                 description: |-
                   RootCAsSecrets defines a list of CA secret used to validate self-signed certificate.
+
                   Deprecated: RootCAsSecrets is deprecated, please use the RootCAs option instead.
                 items:
                   type: string
@@ -2524,6 +2531,7 @@ spec:
                   rootCAsSecrets:
                     description: |-
                       RootCAsSecrets defines a list of CA secret used to validate self-signed certificate.
+
                       Deprecated: RootCAsSecrets is deprecated, please use the RootCAs option instead.
                     items:
                       type: string
@@ -2659,6 +2667,7 @@ spec:
                 description: |-
                   PreferServerCipherSuites defines whether the server chooses a cipher suite among his own instead of among the client's.
                   It is enabled automatically when minVersion or maxVersion is set.
+
                   Deprecated: https://github.com/golang/go/issues/45430
                 type: boolean
               sniStrict:

docs/content/reference/dynamic-configuration/traefik.containo.us_tlsoptions.yaml

@@ -1,114 +0,0 @@
----
-apiVersion: apiextensions.k8s.io/v1
-kind: CustomResourceDefinition
-metadata:
-  annotations:
-    controller-gen.kubebuilder.io/version: v0.16.1
-  name: tlsoptions.traefik.containo.us
-spec:
-  group: traefik.containo.us
-  names:
-    kind: TLSOption
-    listKind: TLSOptionList
-    plural: tlsoptions
-    singular: tlsoption
-  scope: Namespaced
-  versions:
-  - name: v1alpha1
-    schema:
-      openAPIV3Schema:
-        description: |-
-          TLSOption is the CRD implementation of a Traefik TLS Option, allowing to configure some parameters of the TLS connection.
-          More info: https://doc.traefik.io/traefik/v2.11/https/tls/#tls-options
-        properties:
-          apiVersion:
-            description: |-
-              APIVersion defines the versioned schema of this representation of an object.
-              Servers should convert recognized schemas to the latest internal value, and
-              may reject unrecognized values.
-              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources
-            type: string
-          kind:
-            description: |-
-              Kind is a string value representing the REST resource this object represents.
-              Servers may infer this from the endpoint the client submits requests to.
-              Cannot be updated.
-              In CamelCase.
-              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds
-            type: string
-          metadata:
-            type: object
-          spec:
-            description: TLSOptionSpec defines the desired state of a TLSOption.
-            properties:
-              alpnProtocols:
-                description: |-
-                  ALPNProtocols defines the list of supported application level protocols for the TLS handshake, in order of preference.
-                  More info: https://doc.traefik.io/traefik/v2.11/https/tls/#alpn-protocols
-                items:
-                  type: string
-                type: array
-              cipherSuites:
-                description: |-
-                  CipherSuites defines the list of supported cipher suites for TLS versions up to TLS 1.2.
-                  More info: https://doc.traefik.io/traefik/v2.11/https/tls/#cipher-suites
-                items:
-                  type: string
-                type: array
-              clientAuth:
-                description: ClientAuth defines the server's policy for TLS Client
-                  Authentication.
-                properties:
-                  clientAuthType:
-                    description: ClientAuthType defines the client authentication
-                      type to apply.
-                    enum:
-                    - NoClientCert
-                    - RequestClientCert
-                    - RequireAnyClientCert
-                    - VerifyClientCertIfGiven
-                    - RequireAndVerifyClientCert
-                    type: string
-                  secretNames:
-                    description: SecretNames defines the names of the referenced Kubernetes
-                      Secret storing certificate details.
-                    items:
-                      type: string
-                    type: array
-                type: object
-              curvePreferences:
-                description: |-
-                  CurvePreferences defines the preferred elliptic curves.
-                  More info: https://doc.traefik.io/traefik/v2.11/https/tls/#curve-preferences
-                items:
-                  type: string
-                type: array
-              maxVersion:
-                description: |-
-                  MaxVersion defines the maximum TLS version that Traefik will accept.
-                  Possible values: VersionTLS10, VersionTLS11, VersionTLS12, VersionTLS13.
-                  Default: None.
-                type: string
-              minVersion:
-                description: |-
-                  MinVersion defines the minimum TLS version that Traefik will accept.
-                  Possible values: VersionTLS10, VersionTLS11, VersionTLS12, VersionTLS13.
-                  Default: VersionTLS10.
-                type: string
-              preferServerCipherSuites:
-                description: |-
-                  PreferServerCipherSuites defines whether the server chooses a cipher suite among his own instead of among the client's.
-                  It is enabled automatically when minVersion or maxVersion is set.
-                  Deprecated: https://github.com/golang/go/issues/45430
-                type: boolean
-              sniStrict:
-                description: SniStrict defines whether Traefik allows connections
-                  from clients connections that do not specify a server_name extension.
-                type: boolean
-            type: object
-        required:
-        - metadata
-        - spec
-        type: object
-    served: true
-    storage: true

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

@@ -374,6 +374,7 @@ spec:
                       description: |-
                         Syntax defines the router's rule syntax.
                         More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/http/routing/rules-and-priority/#rulesyntax
+
                         Deprecated: Please do not use this field and rewrite the router rules to use the v3 syntax.
                       type: string
                   required:

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

@@ -123,6 +123,7 @@ spec:
                             description: |-
                               ProxyProtocol defines the PROXY protocol configuration.
                               More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/tcp/service/#proxy-protocol
+
                               Deprecated: ProxyProtocol will not be supported in future APIVersions, please use ServersTransport to configure ProxyProtocol instead.
                             properties:
                               version:
@@ -145,6 +146,7 @@ spec:
                               hence fully terminating the connection.
                               It is a duration in milliseconds, defaulting to 100.
                               A negative value means an infinite deadline (i.e. the reading capability is never closed).
+
                               Deprecated: TerminationDelay will not be supported in future APIVersions, please use ServersTransport to configure the TerminationDelay instead.
                             type: integer
                           tls:
@@ -165,6 +167,7 @@ spec:
                       description: |-
                         Syntax defines the router's rule syntax.
                         More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/tcp/routing/rules-and-priority/#rulesyntax
+
                         Deprecated: Please do not use this field and rewrite the router rules to use the v3 syntax.
                       enum:
                       - v3

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

@@ -231,6 +231,7 @@ spec:
                     description: |-
                       AutoDetect specifies whether to let the `Content-Type` header, if it has not been set by the backend,
                       be automatically set to a value derived from the contents of the response.
+
                       Deprecated: AutoDetect option is deprecated, Content-Type middleware is only meant to be used to enable the content-type detection, please remove any usage of this option.
                     type: boolean
                 type: object

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

@@ -69,8 +69,9 @@ spec:
                 description: |-
                   IPWhiteList defines the IPWhiteList middleware configuration.
                   This middleware accepts/refuses connections based on the client IP.
-                  Deprecated: please use IPAllowList instead.
                   More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/tcp/middlewares/ipwhitelist/
+
+                  Deprecated: please use IPAllowList instead.
                 properties:
                   sourceRange:
                     description: SourceRange defines the allowed IPs (or ranges of

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

@@ -139,6 +139,7 @@ spec:
               rootCAsSecrets:
                 description: |-
                   RootCAsSecrets defines a list of CA secret used to validate self-signed certificate.
+
                   Deprecated: RootCAsSecrets is deprecated, please use the RootCAs option instead.
                 items:
                   type: string

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

@@ -124,6 +124,7 @@ spec:
                   rootCAsSecrets:
                     description: |-
                       RootCAsSecrets defines a list of CA secret used to validate self-signed certificate.
+
                       Deprecated: RootCAsSecrets is deprecated, please use the RootCAs option instead.
                     items:
                       type: string

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

@@ -103,6 +103,7 @@ spec:
                 description: |-
                   PreferServerCipherSuites defines whether the server chooses a cipher suite among his own instead of among the client's.
                   It is enabled automatically when minVersion or maxVersion is set.
+
                   Deprecated: https://github.com/golang/go/issues/45430
                 type: boolean
               sniStrict:

integration/access_log_test.go

@@ -245,8 +245,7 @@ func digestParts(resp *http.Response) map[string]string {
 	result := map[string]string{}
 	if len(resp.Header["Www-Authenticate"]) > 0 {
 		wantedHeaders := []string{"nonce", "realm", "qop", "opaque"}
-		responseHeaders := strings.Split(resp.Header["Www-Authenticate"][0], ",")
+		for r := range strings.SplitSeq(resp.Header["Www-Authenticate"][0], ",") {
-		for _, r := range responseHeaders {
 			for _, w := range wantedHeaders {
 				if strings.Contains(r, w) {
 					result[w] = strings.Split(r, `"`)[1]

integration/acme_test.go

@@ -27,6 +27,7 @@ import (
 // ACME test suites.
 type AcmeSuite struct {
 	BaseSuite
+
 	pebbleIP      string
 	fakeDNSServer *dns.Server
 }
@@ -63,11 +64,6 @@ const (
 	wildcardDomain = "*.acme.wtf"
 )
 
-func (s *AcmeSuite) getAcmeURL() string {
-	return fmt.Sprintf("https://%s/dir",
-		net.JoinHostPort(s.pebbleIP, "14000"))
-}
-
 func setupPebbleRootCA() (*http.Transport, error) {
 	path, err := filepath.Abs("fixtures/acme/ssl/pebble.minica.pem")
 	if err != nil {
@@ -540,3 +536,8 @@ func (s *AcmeSuite) retrieveAcmeCertificate(testCase acmeTestCase) {
 		assert.Equal(s.T(), sub.expectedAlgorithm, gotPublicKeyAlgorithm)
 	}
 }
+
+func (s *AcmeSuite) getAcmeURL() string {
+	return fmt.Sprintf("https://%s/dir",
+		net.JoinHostPort(s.pebbleIP, "14000"))
+}

integration/consul_catalog_test.go

@@ -16,6 +16,7 @@ import (
 
 type ConsulCatalogSuite struct {
 	BaseSuite
+
 	consulClient      *api.Client
 	consulAgentClient *api.Client
 	consulURL         string
@@ -53,47 +54,6 @@ func (s *ConsulCatalogSuite) TearDownSuite() {
 	s.BaseSuite.TearDownSuite()
 }
 
-func (s *ConsulCatalogSuite) waitToElectConsulLeader() error {
-	return try.Do(15*time.Second, func() error {
-		leader, err := s.consulClient.Status().Leader()
-
-		if err != nil || len(leader) == 0 {
-			return fmt.Errorf("leader not found. %w", err)
-		}
-
-		return nil
-	})
-}
-
-func (s *ConsulCatalogSuite) waitForConnectCA() error {
-	return try.Do(15*time.Second, func() error {
-		caroots, _, err := s.consulClient.Connect().CARoots(nil)
-
-		if err != nil || len(caroots.Roots) == 0 {
-			return fmt.Errorf("connect CA not fully initialized. %w", err)
-		}
-
-		return nil
-	})
-}
-
-func (s *ConsulCatalogSuite) registerService(reg *api.AgentServiceRegistration, onAgent bool) error {
-	client := s.consulClient
-	if onAgent {
-		client = s.consulAgentClient
-	}
-
-	return client.Agent().ServiceRegister(reg)
-}
-
-func (s *ConsulCatalogSuite) deregisterService(id string, onAgent bool) error {
-	client := s.consulClient
-	if onAgent {
-		client = s.consulAgentClient
-	}
-	return client.Agent().ServiceDeregister(id)
-}
-
 func (s *ConsulCatalogSuite) TestWithNotExposedByDefaultAndDefaultsSettings() {
 	reg1 := &api.AgentServiceRegistration{
 		ID:      "whoami1",
@@ -837,3 +797,44 @@ func (s *ConsulCatalogSuite) TestConsulConnect_NotAware() {
 	err = s.deregisterService("whoami1", false)
 	require.NoError(s.T(), err)
 }
+
+func (s *ConsulCatalogSuite) waitToElectConsulLeader() error {
+	return try.Do(15*time.Second, func() error {
+		leader, err := s.consulClient.Status().Leader()
+
+		if err != nil || len(leader) == 0 {
+			return fmt.Errorf("leader not found. %w", err)
+		}
+
+		return nil
+	})
+}
+
+func (s *ConsulCatalogSuite) waitForConnectCA() error {
+	return try.Do(15*time.Second, func() error {
+		caroots, _, err := s.consulClient.Connect().CARoots(nil)
+
+		if err != nil || len(caroots.Roots) == 0 {
+			return fmt.Errorf("connect CA not fully initialized. %w", err)
+		}
+
+		return nil
+	})
+}
+
+func (s *ConsulCatalogSuite) registerService(reg *api.AgentServiceRegistration, onAgent bool) error {
+	client := s.consulClient
+	if onAgent {
+		client = s.consulAgentClient
+	}
+
+	return client.Agent().ServiceRegister(reg)
+}
+
+func (s *ConsulCatalogSuite) deregisterService(id string, onAgent bool) error {
+	client := s.consulClient
+	if onAgent {
+		client = s.consulAgentClient
+	}
+	return client.Agent().ServiceDeregister(id)
+}

integration/consul_test.go

@@ -25,6 +25,7 @@ import (
 // Consul test suites.
 type ConsulSuite struct {
 	BaseSuite
+
 	kvClient  store.Store
 	consulURL string
 }
@@ -162,16 +163,6 @@ func (s *ConsulSuite) TestSimpleConfiguration() {
 	}
 }
 
-func (s *ConsulSuite) assertWhoami(host string, expectedStatusCode int) {
-	req, err := http.NewRequest(http.MethodGet, "http://127.0.0.1:8000", nil)
-	require.NoError(s.T(), err)
-	req.Host = host
-
-	resp, err := try.ResponseUntilStatusCode(req, 15*time.Second, expectedStatusCode)
-	require.NoError(s.T(), err)
-	resp.Body.Close()
-}
-
 func (s *ConsulSuite) TestDeleteRootKey() {
 	// This test case reproduce the issue: https://github.com/traefik/traefik/issues/8092
 
@@ -220,3 +211,13 @@ func (s *ConsulSuite) TestDeleteRootKey() {
 	s.assertWhoami("kv1.localhost", http.StatusNotFound)
 	s.assertWhoami("kv2.localhost", http.StatusNotFound)
 }
+
+func (s *ConsulSuite) assertWhoami(host string, expectedStatusCode int) {
+	req, err := http.NewRequest(http.MethodGet, "http://127.0.0.1:8000", nil)
+	require.NoError(s.T(), err)
+	req.Host = host
+
+	resp, err := try.ResponseUntilStatusCode(req, 15*time.Second, expectedStatusCode)
+	require.NoError(s.T(), err)
+	resp.Body.Close()
+}

integration/docker_test.go

@@ -81,7 +81,7 @@ func (s *DockerSuite) TestDefaultDockerContainers() {
 	body, err := io.ReadAll(resp.Body)
 	require.NoError(s.T(), err)
 
-	var version map[string]interface{}
+	var version map[string]any
 
 	assert.NoError(s.T(), json.Unmarshal(body, &version))
 	assert.Equal(s.T(), "swarm/1.0.0", version["Version"])
@@ -145,7 +145,7 @@ func (s *DockerSuite) TestDockerContainersWithLabels() {
 	body, err := io.ReadAll(resp.Body)
 	require.NoError(s.T(), err)
 
-	var version map[string]interface{}
+	var version map[string]any
 
 	assert.NoError(s.T(), json.Unmarshal(body, &version))
 	assert.Equal(s.T(), "swarm/1.0.0", version["Version"])
@@ -203,7 +203,7 @@ func (s *DockerSuite) TestRestartDockerContainers() {
 	body, err := io.ReadAll(resp.Body)
 	require.NoError(s.T(), err)
 
-	var version map[string]interface{}
+	var version map[string]any
 
 	assert.NoError(s.T(), json.Unmarshal(body, &version))
 	assert.Equal(s.T(), "swarm/1.0.0", version["Version"])

integration/dual_logging_test.go

@@ -21,6 +21,7 @@ const traefikTestOTLPLogFile = "traefik_otlp.log"
 // DualLoggingSuite tests that both OTLP and stdout logging can work together.
 type DualLoggingSuite struct {
 	BaseSuite
+
 	otlpLogs  []string
 	collector *httptest.Server
 }

integration/error_pages_test.go

@@ -14,6 +14,7 @@ import (
 // ErrorPagesSuite test suites.
 type ErrorPagesSuite struct {
 	BaseSuite
+
 	ErrorPageIP string
 	BackendIP   string
 }

integration/etcd_test.go

@@ -23,6 +23,7 @@ import (
 // etcd test suites.
 type EtcdSuite struct {
 	BaseSuite
+
 	kvClient store.Store
 	etcdAddr string
 }

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

@@ -374,6 +374,7 @@ spec:
                       description: |-
                         Syntax defines the router's rule syntax.
                         More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/http/routing/rules-and-priority/#rulesyntax
+
                         Deprecated: Please do not use this field and rewrite the router rules to use the v3 syntax.
                       type: string
                   required:
@@ -585,6 +586,7 @@ spec:
                             description: |-
                               ProxyProtocol defines the PROXY protocol configuration.
                               More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/tcp/service/#proxy-protocol
+
                               Deprecated: ProxyProtocol will not be supported in future APIVersions, please use ServersTransport to configure ProxyProtocol instead.
                             properties:
                               version:
@@ -607,6 +609,7 @@ spec:
                               hence fully terminating the connection.
                               It is a duration in milliseconds, defaulting to 100.
                               A negative value means an infinite deadline (i.e. the reading capability is never closed).
+
                               Deprecated: TerminationDelay will not be supported in future APIVersions, please use ServersTransport to configure the TerminationDelay instead.
                             type: integer
                           tls:
@@ -627,6 +630,7 @@ spec:
                       description: |-
                         Syntax defines the router's rule syntax.
                         More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/tcp/routing/rules-and-priority/#rulesyntax
+
                         Deprecated: Please do not use this field and rewrite the router rules to use the v3 syntax.
                       enum:
                       - v3
@@ -1061,6 +1065,7 @@ spec:
                     description: |-
                       AutoDetect specifies whether to let the `Content-Type` header, if it has not been set by the backend,
                       be automatically set to a value derived from the contents of the response.
+
                       Deprecated: AutoDetect option is deprecated, Content-Type middleware is only meant to be used to enable the content-type detection, please remove any usage of this option.
                     type: boolean
                 type: object
@@ -2213,8 +2218,9 @@ spec:
                 description: |-
                   IPWhiteList defines the IPWhiteList middleware configuration.
                   This middleware accepts/refuses connections based on the client IP.
-                  Deprecated: please use IPAllowList instead.
                   More info: https://doc.traefik.io/traefik/v3.6/reference/routing-configuration/tcp/middlewares/ipwhitelist/
+
+                  Deprecated: please use IPAllowList instead.
                 properties:
                   sourceRange:
                     description: SourceRange defines the allowed IPs (or ranges of
@@ -2371,6 +2377,7 @@ spec:
               rootCAsSecrets:
                 description: |-
                   RootCAsSecrets defines a list of CA secret used to validate self-signed certificate.
+
                   Deprecated: RootCAsSecrets is deprecated, please use the RootCAs option instead.
                 items:
                   type: string
@@ -2525,6 +2532,7 @@ spec:
                   rootCAsSecrets:
                     description: |-
                       RootCAsSecrets defines a list of CA secret used to validate self-signed certificate.
+
                       Deprecated: RootCAsSecrets is deprecated, please use the RootCAs option instead.
                     items:
                       type: string
@@ -2660,6 +2668,7 @@ spec:
                 description: |-
                   PreferServerCipherSuites defines whether the server chooses a cipher suite among his own instead of among the client's.
                   It is enabled automatically when minVersion or maxVersion is set.
+
                   Deprecated: https://github.com/golang/go/issues/45430
                 type: boolean
               sniStrict:

integration/healthcheck_test.go

@@ -19,6 +19,7 @@ import (
 // HealthCheck test suites.
 type HealthCheckSuite struct {
 	BaseSuite
+
 	whoami1IP string
 	whoami2IP string
 	whoami3IP string

integration/helloworld/helloworld.pb.go

@@ -187,7 +187,7 @@ func RegisterGreeterServer(s *grpc.Server, srv GreeterServer) {
 	s.RegisterService(&_Greeter_serviceDesc, srv)
 }
 
-func _Greeter_SayHello_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+func _Greeter_SayHello_Handler(srv any, ctx context.Context, dec func(any) error, interceptor grpc.UnaryServerInterceptor) (any, error) {
 	in := new(HelloRequest)
 	if err := dec(in); err != nil {
 		return nil, err
@@ -199,13 +199,13 @@ func _Greeter_SayHello_Handler(srv interface{}, ctx context.Context, dec func(in
 		Server:     srv,
 		FullMethod: "/helloworld.Greeter/SayHello",
 	}
-	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+	handler := func(ctx context.Context, req any) (any, error) {
 		return srv.(GreeterServer).SayHello(ctx, req.(*HelloRequest))
 	}
 	return interceptor(ctx, in, info, handler)
 }
 
-func _Greeter_StreamExample_Handler(srv interface{}, stream grpc.ServerStream) error {
+func _Greeter_StreamExample_Handler(srv any, stream grpc.ServerStream) error {
 	m := new(StreamExampleRequest)
 	if err := stream.RecvMsg(m); err != nil {
 		return err

integration/https_test.go

@@ -877,40 +877,6 @@ func (s *HTTPSSuite) TestWithSNIDynamicConfigRouteWithTlsConfigurationDeletion()
 	require.NoError(s.T(), err)
 }
 
-// modifyCertificateConfFileContent replaces the content of a HTTPS configuration file.
-func (s *HTTPSSuite) modifyCertificateConfFileContent(certFileName, confFileName string) {
-	file, err := os.OpenFile("./"+confFileName, os.O_WRONLY, os.ModeExclusive)
-	require.NoError(s.T(), err)
-	defer func() {
-		file.Close()
-	}()
-	err = file.Truncate(0)
-	require.NoError(s.T(), err)
-
-	// If certificate file is not provided, just truncate the configuration file
-	if len(certFileName) > 0 {
-		tlsConf := dynamic.Configuration{
-			TLS: &dynamic.TLSConfiguration{
-				Certificates: []*traefiktls.CertAndStores{
-					{
-						Certificate: traefiktls.Certificate{
-							CertFile: types.FileOrContent("fixtures/https/" + certFileName + ".cert"),
-							KeyFile:  types.FileOrContent("fixtures/https/" + certFileName + ".key"),
-						},
-					},
-				},
-			},
-		}
-
-		var confBuffer bytes.Buffer
-		err := toml.NewEncoder(&confBuffer).Encode(tlsConf)
-		require.NoError(s.T(), err)
-
-		_, err = file.Write(confBuffer.Bytes())
-		require.NoError(s.T(), err)
-	}
-}
-
 func (s *HTTPSSuite) TestEntryPointHttpsRedirectAndPathModification() {
 	file := s.adaptFile("fixtures/https/https_redirect.toml", struct{}{})
 	s.traefikCmd(withConfigFile(file))
@@ -1177,6 +1143,40 @@ func (s *HTTPSSuite) TestWithInvalidTLSOption() {
 	}
 }
 
+// modifyCertificateConfFileContent replaces the content of a HTTPS configuration file.
+func (s *HTTPSSuite) modifyCertificateConfFileContent(certFileName, confFileName string) {
+	file, err := os.OpenFile("./"+confFileName, os.O_WRONLY, os.ModeExclusive)
+	require.NoError(s.T(), err)
+	defer func() {
+		file.Close()
+	}()
+	err = file.Truncate(0)
+	require.NoError(s.T(), err)
+
+	// If certificate file is not provided, just truncate the configuration file
+	if len(certFileName) > 0 {
+		tlsConf := dynamic.Configuration{
+			TLS: &dynamic.TLSConfiguration{
+				Certificates: []*traefiktls.CertAndStores{
+					{
+						Certificate: traefiktls.Certificate{
+							CertFile: types.FileOrContent("fixtures/https/" + certFileName + ".cert"),
+							KeyFile:  types.FileOrContent("fixtures/https/" + certFileName + ".key"),
+						},
+					},
+				},
+			},
+		}
+
+		var confBuffer bytes.Buffer
+		err := toml.NewEncoder(&confBuffer).Encode(tlsConf)
+		require.NoError(s.T(), err)
+
+		_, err = file.Write(confBuffer.Bytes())
+		require.NoError(s.T(), err)
+	}
+}
+
 func (s *SimpleSuite) TestMaxConcurrentStream() {
 	file := s.adaptFile("fixtures/https/max_concurrent_stream.toml", struct{}{})
 

integration/integration_test.go

@@ -71,45 +71,12 @@ type composeDeploy struct {
 
 type BaseSuite struct {
 	suite.Suite
+
 	containers map[string]testcontainers.Container
 	network    *testcontainers.DockerNetwork
 	hostIP     string
 }
 
-func (s *BaseSuite) waitForTraefik(containerName string) {
-	time.Sleep(1 * time.Second)
-
-	// Wait for Traefik to turn ready.
-	req, err := http.NewRequest(http.MethodGet, "http://127.0.0.1:8080/api/rawdata", nil)
-	require.NoError(s.T(), err)
-
-	err = try.Request(req, 2*time.Second, try.StatusCodeIs(http.StatusOK), try.BodyContains(containerName))
-	require.NoError(s.T(), err)
-}
-
-func (s *BaseSuite) displayTraefikLogFile(path string) {
-	if s.T().Failed() {
-		if _, err := os.Stat(path); !os.IsNotExist(err) {
-			content, errRead := os.ReadFile(path)
-			// TODO TestName
-			// fmt.Printf("%s: Traefik logs: \n", c.TestName())
-			fmt.Print("Traefik logs: \n")
-			if errRead == nil {
-				fmt.Println(string(content))
-			} else {
-				fmt.Println(errRead)
-			}
-		} else {
-			// fmt.Printf("%s: No Traefik logs.\n", c.TestName())
-			fmt.Print("No Traefik logs.\n")
-		}
-		errRemove := os.Remove(path)
-		if errRemove != nil {
-			fmt.Println(errRemove)
-		}
-	}
-}
-
 func (s *BaseSuite) SetupSuite() {
 	if isDockerDesktop(s.T()) {
 		_, err := os.Stat(tailscaleSecretFilePath)
@@ -409,7 +376,7 @@ func (s *BaseSuite) displayTraefikLog(output *bytes.Buffer) {
 	if output == nil || output.Len() == 0 {
 		log.Info().Msg("No Traefik logs.")
 	} else {
-		for _, line := range strings.Split(output.String(), "\n") {
+		for line := range strings.SplitSeq(output.String(), "\n") {
 			log.Info().Msg(line)
 		}
 	}
@@ -425,7 +392,7 @@ func (s *BaseSuite) getDockerHost() string {
 	return dockerHost
 }
 
-func (s *BaseSuite) adaptFile(path string, tempObjects interface{}) string {
+func (s *BaseSuite) adaptFile(path string, tempObjects any) string {
 	// Load file
 	tmpl, err := template.ParseFiles(path)
 	require.NoError(s.T(), err)
@@ -513,3 +480,37 @@ func (s *BaseSuite) composeExec(service string, args ...string) string {
 
 	return string(content)
 }
+
+func (s *BaseSuite) waitForTraefik(containerName string) {
+	time.Sleep(1 * time.Second)
+
+	// Wait for Traefik to turn ready.
+	req, err := http.NewRequest(http.MethodGet, "http://127.0.0.1:8080/api/rawdata", nil)
+	require.NoError(s.T(), err)
+
+	err = try.Request(req, 2*time.Second, try.StatusCodeIs(http.StatusOK), try.BodyContains(containerName))
+	require.NoError(s.T(), err)
+}
+
+func (s *BaseSuite) displayTraefikLogFile(path string) {
+	if s.T().Failed() {
+		if _, err := os.Stat(path); !os.IsNotExist(err) {
+			content, errRead := os.ReadFile(path)
+			// TODO TestName
+			// fmt.Printf("%s: Traefik logs: \n", c.TestName())
+			fmt.Print("Traefik logs: \n")
+			if errRead == nil {
+				fmt.Println(string(content))
+			} else {
+				fmt.Println(errRead)
+			}
+		} else {
+			// fmt.Printf("%s: No Traefik logs.\n", c.TestName())
+			fmt.Print("No Traefik logs.\n")
+		}
+		errRemove := os.Remove(path)
+		if errRemove != nil {
+			fmt.Println(errRemove)
+		}
+	}
+}

integration/log_rotation_test.go

@@ -1,5 +1,4 @@
 //go:build !windows
-// +build !windows
 
 package integration
 

integration/proxy_protocol_test.go

@@ -3,6 +3,7 @@ package integration
 import (
 	"bufio"
 	"net"
+	"strings"
 	"testing"
 	"time"
 
@@ -15,6 +16,7 @@ import (
 
 type ProxyProtocolSuite struct {
 	BaseSuite
+
 	whoamiIP string
 }
 
@@ -124,15 +126,16 @@ func proxyProtoRequest(address string, version byte) (string, error) {
 	}
 
 	// Read the response from the server
-	var content string
+	var content strings.Builder
 	scanner := bufio.NewScanner(conn)
 	for scanner.Scan() {
-		content += scanner.Text() + "\n"
+		content.WriteString(scanner.Text())
+		content.WriteString("\n")
 	}
 
 	if scanner.Err() != nil {
 		return "", err
 	}
 
-	return content, nil
+	return content.String(), nil
 }

integration/ratelimit_test.go

@@ -13,6 +13,7 @@ import (
 
 type RateLimitSuite struct {
 	BaseSuite
+
 	ServerIP      string
 	RedisEndpoint string
 }

integration/redis_sentinel_test.go

@@ -28,6 +28,7 @@ import (
 // Redis test suites.
 type RedisSentinelSuite struct {
 	BaseSuite
+
 	kvClient       store.Store
 	redisEndpoints []string
 }
@@ -75,36 +76,6 @@ func (s *RedisSentinelSuite) TearDownSuite() {
 	}
 }
 
-func (s *RedisSentinelSuite) setupSentinelConfiguration(ports []string) {
-	for i, port := range ports {
-		templateValue := struct{ SentinelPort string }{SentinelPort: port}
-
-		// Load file
-		templateFile := "resources/compose/config/sentinel_template.conf"
-		tmpl, err := template.ParseFiles(templateFile)
-		require.NoError(s.T(), err)
-
-		folder, prefix := filepath.Split(templateFile)
-
-		fileName := fmt.Sprintf("%s/sentinel%d.conf", folder, i+1)
-		tmpFile, err := os.Create(fileName)
-		require.NoError(s.T(), err)
-		defer tmpFile.Close()
-
-		err = tmpFile.Chmod(0o666)
-		require.NoError(s.T(), err)
-
-		model := structs.Map(templateValue)
-		model["SelfFilename"] = tmpFile.Name()
-
-		err = tmpl.ExecuteTemplate(tmpFile, prefix, model)
-		require.NoError(s.T(), err)
-
-		err = tmpFile.Sync()
-		require.NoError(s.T(), err)
-	}
-}
-
 func (s *RedisSentinelSuite) TestSentinelConfiguration() {
 	file := s.adaptFile("fixtures/redis/sentinel.toml", struct{ RedisAddress string }{
 		RedisAddress: strings.Join(s.redisEndpoints, `","`),
@@ -201,3 +172,33 @@ func (s *RedisSentinelSuite) TestSentinelConfiguration() {
 		log.Info().Msg(text)
 	}
 }
+
+func (s *RedisSentinelSuite) setupSentinelConfiguration(ports []string) {
+	for i, port := range ports {
+		templateValue := struct{ SentinelPort string }{SentinelPort: port}
+
+		// Load file
+		templateFile := "resources/compose/config/sentinel_template.conf"
+		tmpl, err := template.ParseFiles(templateFile)
+		require.NoError(s.T(), err)
+
+		folder, prefix := filepath.Split(templateFile)
+
+		fileName := fmt.Sprintf("%s/sentinel%d.conf", folder, i+1)
+		tmpFile, err := os.Create(fileName)
+		require.NoError(s.T(), err)
+		defer tmpFile.Close()
+
+		err = tmpFile.Chmod(0o666)
+		require.NoError(s.T(), err)
+
+		model := structs.Map(templateValue)
+		model["SelfFilename"] = tmpFile.Name()
+
+		err = tmpl.ExecuteTemplate(tmpFile, prefix, model)
+		require.NoError(s.T(), err)
+
+		err = tmpFile.Sync()
+		require.NoError(s.T(), err)
+	}
+}

integration/redis_test.go

@@ -24,6 +24,7 @@ import (
 // Redis test suites.
 type RedisSuite struct {
 	BaseSuite
+
 	kvClient       store.Store
 	redisEndpoints []string
 }

integration/rest_test.go

@@ -18,6 +18,7 @@ import (
 
 type RestSuite struct {
 	BaseSuite
+
 	whoamiAddr string
 }
 

integration/retry_test.go

@@ -15,6 +15,7 @@ import (
 
 type RetrySuite struct {
 	BaseSuite
+
 	whoamiIP string
 }
 

integration/tcp_healthcheck_test.go

@@ -15,6 +15,7 @@ import (
 // TCPHealthCheckSuite test suite for TCP health checks.
 type TCPHealthCheckSuite struct {
 	BaseSuite
+
 	whoamitcp1IP string
 	whoamitcp2IP string
 }

integration/tracing_test.go

@@ -21,6 +21,7 @@ import (
 
 type TracingSuite struct {
 	BaseSuite
+
 	whoamiIP        string
 	whoamiPort      int
 	tempoIP         string

integration/try/try.go

@@ -19,6 +19,7 @@ const (
 type timedAction func(timeout time.Duration, operation DoCondition) error
 
 // Sleep pauses the current goroutine for at least the duration d.
+//
 // Deprecated: Use only when use another Try[...] functions is not possible.
 func Sleep(d time.Duration) {
 	d = applyCIMultiplier(d)
@@ -92,10 +93,7 @@ func Do(timeout time.Duration, operation DoCondition) error {
 		panic("timeout must be larger than zero")
 	}
 
-	interval := time.Duration(math.Ceil(float64(timeout) / 15.0))
+	interval := min(time.Duration(math.Ceil(float64(timeout)/15.0)), maxInterval)
-	if interval > maxInterval {
-		interval = maxInterval
-	}
 
 	timeout = applyCIMultiplier(timeout)
 

integration/zk_test.go

@@ -24,6 +24,7 @@ import (
 // Zk test suites.
 type ZookeeperSuite struct {
 	BaseSuite
+
 	kvClient      store.Store
 	zookeeperAddr string
 }

internal/gendoc.go

@@ -196,7 +196,7 @@ type errWriter struct {
 	err error
 }
 
-func (ew *errWriter) writeln(a ...interface{}) {
+func (ew *errWriter) writeln(a ...any) {
 	if ew.err != nil {
 		return
 	}

pkg/api/criterion.go

@@ -84,13 +84,7 @@ func (c *searchCriterion) filterMiddleware(mns []string) bool {
 		return true
 	}
 
-	for _, mn := range mns {
+	return slices.Contains(mns, c.MiddlewareName)
-		if c.MiddlewareName == mn {
-			return true
-		}
-	}
-
-	return false
 }
 
 func pagination(request *http.Request, maximum int) (pageInfo, error) {
@@ -109,10 +103,7 @@ func pagination(request *http.Request, maximum int) (pageInfo, error) {
 		return pageInfo{}, fmt.Errorf("invalid request: page: %d, per_page: %d", page, perPage)
 	}
 
-	endIndex := startIndex + perPage
+	endIndex := min(startIndex+perPage, maximum)
-	if endIndex >= maximum {
-		endIndex = maximum
-	}
 
 	nextPage := 1
 	if page*perPage < maximum {

pkg/api/debug.go

@@ -15,7 +15,7 @@ func init() {
 	expvar.Publish("Goroutines2", expvar.Func(goroutines))
 }
 
-func goroutines() interface{} {
+func goroutines() any {
 	return runtime.NumGoroutine()
 }
 

pkg/api/handler.go

@@ -30,11 +30,13 @@ func writeError(rw http.ResponseWriter, msg string, code int) {
 
 type serviceInfoRepresentation struct {
 	*runtime.ServiceInfo
+
 	ServerStatus map[string]string `json:"serverStatus,omitempty"`
 }
 
 type tcpServiceInfoRepresentation struct {
 	*runtime.TCPServiceInfo
+
 	ServerStatus map[string]string `json:"serverStatus,omitempty"`
 }
 
@@ -164,7 +166,7 @@ func getProviderName(id string) string {
 	return strings.SplitN(id, "@", 2)[1]
 }
 
-func extractType(element interface{}) string {
+func extractType(element any) string {
 	v := reflect.ValueOf(element).Elem()
 	for i := range v.NumField() {
 		field := v.Field(i)

pkg/api/handler_entrypoint.go

@@ -15,6 +15,7 @@ import (
 
 type entryPointRepresentation struct {
 	*static.EntryPoint
+
 	Name string `json:"name,omitempty"`
 }
 

pkg/api/handler_entrypoint_test.go

@@ -235,7 +235,7 @@ func TestHandler_EntryPoints(t *testing.T) {
 			require.NoError(t, err)
 
 			if *updateExpected {
-				var results interface{}
+				var results any
 				err := json.Unmarshal(contents, &results)
 				require.NoError(t, err)
 

pkg/api/handler_http.go

@@ -16,6 +16,7 @@ import (
 
 type routerRepresentation struct {
 	*runtime.RouterInfo
+
 	Name     string `json:"name,omitempty"`
 	Provider string `json:"provider,omitempty"`
 }
@@ -34,6 +35,7 @@ func newRouterRepresentation(name string, rt *runtime.RouterInfo) routerRepresen
 
 type serviceRepresentation struct {
 	*runtime.ServiceInfo
+
 	Name         string            `json:"name,omitempty"`
 	Provider     string            `json:"provider,omitempty"`
 	Type         string            `json:"type,omitempty"`
@@ -52,6 +54,7 @@ func newServiceRepresentation(name string, si *runtime.ServiceInfo) serviceRepre
 
 type middlewareRepresentation struct {
 	*runtime.MiddlewareInfo
+
 	Name     string `json:"name,omitempty"`
 	Provider string `json:"provider,omitempty"`
 	Type     string `json:"type,omitempty"`

pkg/api/handler_http_test.go

@@ -1028,7 +1028,7 @@ func TestHandler_HTTP(t *testing.T) {
 			require.NoError(t, err)
 
 			if *updateExpected {
-				var results interface{}
+				var results any
 				err := json.Unmarshal(contents, &results)
 				require.NoError(t, err)
 

pkg/api/handler_overview_test.go

@@ -239,7 +239,7 @@ func TestHandler_Overview(t *testing.T) {
 					KubernetesCRD:     &crd.Provider{},
 					Rest:              &rest.Provider{},
 					Plugin: map[string]static.PluginConf{
-						"test": map[string]interface{}{},
+						"test": map[string]any{},
 					},
 				},
 			},
@@ -292,7 +292,7 @@ func TestHandler_Overview(t *testing.T) {
 			require.NoError(t, err)
 
 			if *updateExpected {
-				var results interface{}
+				var results any
 				err := json.Unmarshal(contents, &results)
 				require.NoError(t, err)
 

pkg/api/handler_tcp.go

@@ -15,6 +15,7 @@ import (
 
 type tcpRouterRepresentation struct {
 	*runtime.TCPRouterInfo
+
 	Name     string `json:"name,omitempty"`
 	Provider string `json:"provider,omitempty"`
 }
@@ -29,6 +30,7 @@ func newTCPRouterRepresentation(name string, rt *runtime.TCPRouterInfo) tcpRoute
 
 type tcpServiceRepresentation struct {
 	*runtime.TCPServiceInfo
+
 	Name         string            `json:"name,omitempty"`
 	Provider     string            `json:"provider,omitempty"`
 	Type         string            `json:"type,omitempty"`
@@ -47,6 +49,7 @@ func newTCPServiceRepresentation(name string, si *runtime.TCPServiceInfo) tcpSer
 
 type tcpMiddlewareRepresentation struct {
 	*runtime.TCPMiddlewareInfo
+
 	Name     string `json:"name,omitempty"`
 	Provider string `json:"provider,omitempty"`
 	Type     string `json:"type,omitempty"`

pkg/api/handler_tcp_test.go

@@ -964,7 +964,7 @@ func TestHandler_TCP(t *testing.T) {
 			require.NoError(t, err)
 
 			if *updateExpected {
-				var results interface{}
+				var results any
 				err := json.Unmarshal(contents, &results)
 				require.NoError(t, err)
 

pkg/api/handler_test.go

@@ -178,7 +178,7 @@ func TestHandler_GetMiddleware(t *testing.T) {
 		middlewareName string
 		conf           runtime.Configuration
 		expectedStatus int
-		expected       interface{}
+		expected       any
 	}{
 		{
 			desc:           "Middleware not found",

pkg/api/handler_udp.go

@@ -15,6 +15,7 @@ import (
 
 type udpRouterRepresentation struct {
 	*runtime.UDPRouterInfo
+
 	Name     string `json:"name,omitempty"`
 	Provider string `json:"provider,omitempty"`
 }
@@ -29,6 +30,7 @@ func newUDPRouterRepresentation(name string, rt *runtime.UDPRouterInfo) udpRoute
 
 type udpServiceRepresentation struct {
 	*runtime.UDPServiceInfo
+
 	Name     string `json:"name,omitempty"`
 	Provider string `json:"provider,omitempty"`
 	Type     string `json:"type,omitempty"`

pkg/api/handler_udp_test.go

@@ -594,7 +594,7 @@ func TestHandler_UDP(t *testing.T) {
 			require.NoError(t, err)
 
 			if *updateExpected {
-				var results interface{}
+				var results any
 				err := json.Unmarshal(contents, &results)
 				require.NoError(t, err)
 

pkg/cli/deprecation.go

@@ -82,7 +82,7 @@ func logDeprecations(arguments []string) (bool, error) {
 	if filePath != "" {
 		// We don't rely on the Parser file loader here to avoid issues with unknown fields.
 		// Parse file content into a generic map.
-		var fileConfig map[string]interface{}
+		var fileConfig map[string]any
 		if err := file.Decode(filePath, &fileConfig); err != nil {
 			return false, fmt.Errorf("decoding configuration file %s: %w", filePath, err)
 		}
@@ -106,7 +106,7 @@ func logDeprecations(arguments []string) (bool, error) {
 	if len(vars) > 0 {
 		// We don't rely on the Parser env loader here to avoid issues with unknown fields.
 		// Decode environment variables to a generic map.
-		var envConfig map[string]interface{}
+		var envConfig map[string]any
 		if err := env.Decode(vars, env.DefaultNamePrefix, &envConfig); err != nil {
 			return false, fmt.Errorf("decoding environment variables: %w", err)
 		}
@@ -130,9 +130,9 @@ func logDeprecations(arguments []string) (bool, error) {
 
 // flattenToLabels recursively flattens a nested map into label key-value pairs.
 // Example: {"experimental": {"http3": true}} -> {"traefik.experimental.http3": "true"}.
-func flattenToLabels(config interface{}, currKey string, labels map[string]string) {
+func flattenToLabels(config any, currKey string, labels map[string]string) {
 	switch v := config.(type) {
-	case map[string]interface{}:
+	case map[string]any:
 		for key, value := range v {
 			newKey := key
 			if currKey != "" {
@@ -140,7 +140,7 @@ func flattenToLabels(config interface{}, currKey string, labels map[string]strin
 			}
 			flattenToLabels(value, newKey, labels)
 		}
-	case []interface{}:
+	case []any:
 		for i, item := range v {
 			newKey := currKey + "[" + strconv.Itoa(i) + "]"
 			flattenToLabels(item, newKey, labels)
@@ -168,7 +168,7 @@ func parseDeprecatedConfig(labels map[string]string) (*configuration, error) {
 
 	// Filter unknown nodes and check for deprecated options.
 	config := &configuration{}
-	filterUnknownNodes(reflect.TypeOf(config), node)
+	filterUnknownNodes(reflect.TypeFor[*configuration](), node)
 
 	// If no config remains we can return without error, to allow other loaders to proceed.
 	if node == nil || len(node.Children) == 0 {

pkg/cli/loader_file.go

@@ -62,7 +62,7 @@ func (f *FileLoader) Load(args []string, cmd *cli.Command) (bool, error) {
 
 // loadConfigFiles tries to decode the given configuration file and all default locations for the configuration file.
 // It stops as soon as decoding one of them is successful.
-func loadConfigFiles(configFile string, element interface{}) (string, error) {
+func loadConfigFiles(configFile string, element any) (string, error) {
 	finder := cli.Finder{
 		BasePaths:  []string{"/etc/traefik/traefik", "$XDG_CONFIG_HOME/traefik", "$HOME/.config/traefik", "./traefik"},
 		Extensions: []string{"toml", "yaml", "yml"},

pkg/collector/hydratation/hydration.go

@@ -18,7 +18,7 @@ const (
 )
 
 // Hydrate hydrates a configuration.
-func Hydrate(element interface{}) error {
+func Hydrate(element any) error {
 	field := reflect.ValueOf(element)
 	return fill(field)
 }
@@ -81,7 +81,7 @@ func fill(field reflect.Value) error {
 	return nil
 }
 
-func setTyped(field reflect.Value, i interface{}) {
+func setTyped(field reflect.Value, i any) {
 	baseValue := reflect.ValueOf(i)
 	if field.Kind().String() == field.Type().String() {
 		field.Set(baseValue)

pkg/config/dynamic/config_test.go

@@ -21,7 +21,7 @@ func TestDeepCopy(t *testing.T) {
 
 	cfgDeepCopy := cfg.DeepCopy()
 	assert.NotEqual(t, reflect.ValueOf(cfgDeepCopy), reflect.ValueOf(cfg))
-	assert.Equal(t, reflect.TypeOf(cfgDeepCopy), reflect.TypeOf(cfg))
+	assert.Equal(t, reflect.TypeOf(cfgDeepCopy), reflect.TypeOf(cfg)) //nolint:modernize // Comparing runtime types of two values.
 	assert.Equal(t, cfgDeepCopy, cfg)
 
 	// Update cfg
@@ -32,6 +32,6 @@ func TestDeepCopy(t *testing.T) {
 	assert.Equal(t, cfgCopy, cfg)
 
 	assert.NotEqual(t, reflect.ValueOf(cfgDeepCopy), reflect.ValueOf(cfg))
-	assert.Equal(t, reflect.TypeOf(cfgDeepCopy), reflect.TypeOf(cfg))
+	assert.Equal(t, reflect.TypeOf(cfgDeepCopy), reflect.TypeOf(cfg)) //nolint:modernize // Comparing runtime types of two values.
 	assert.NotEqual(t, cfgDeepCopy, cfg)
 }

pkg/config/dynamic/middlewares.go

@@ -69,6 +69,7 @@ type GrpcWeb struct {
 type ContentType struct {
 	// AutoDetect specifies whether to let the `Content-Type` header, if it has not been set by the backend,
 	// be automatically set to a value derived from the contents of the response.
+	//
 	// Deprecated: AutoDetect option is deprecated, Content-Type middleware is only meant to be used to enable the content-type detection, please remove any usage of this option.
 	AutoDetect *bool `json:"autoDetect,omitempty" toml:"autoDetect,omitempty" yaml:"autoDetect,omitempty" export:"true"`
 }
@@ -481,6 +482,7 @@ func (s *IPStrategy) Get() (ip.Strategy, error) {
 // IPWhiteList holds the IP whitelist middleware configuration.
 // This middleware limits allowed requests based on the client IP.
 // More info: https://doc.traefik.io/traefik/v3.6/middlewares/http/ipwhitelist/
+//
 // Deprecated: please use IPAllowList instead.
 type IPWhiteList struct {
 	// SourceRange defines the set of allowed IPs (or ranges of allowed IPs by using CIDR notation). Required.

pkg/config/dynamic/plugins_test.go

@@ -44,11 +44,11 @@ func TestPluginConf_DeepCopy_mapOfStruct(t *testing.T) {
 }
 
 func TestPluginConf_DeepCopy_map(t *testing.T) {
-	m := map[string]interface{}{
+	m := map[string]any{
 		"name": "bar",
 	}
 	p := PluginConf{
-		"config": map[string]interface{}{
+		"config": map[string]any{
 			"foo": m,
 		},
 	}
@@ -64,7 +64,7 @@ func TestPluginConf_DeepCopy_map(t *testing.T) {
 
 func TestPluginConf_DeepCopy_panic(t *testing.T) {
 	p := &PluginConf{
-		"config": map[string]interface{}{
+		"config": map[string]any{
 			"foo": &Foo{Name: "gigi"},
 		},
 	}

pkg/config/dynamic/tcp_config.go

@@ -88,6 +88,7 @@ type TCPServersLoadBalancer struct {
 	Servers          []TCPServer `json:"servers,omitempty" toml:"servers,omitempty" yaml:"servers,omitempty" label-slice-as-struct:"server" export:"true"`
 	ServersTransport string      `json:"serversTransport,omitempty" toml:"serversTransport,omitempty" yaml:"serversTransport,omitempty" export:"true"`
 	// ProxyProtocol holds the PROXY Protocol configuration.
+	//
 	// Deprecated: use ServersTransport to configure ProxyProtocol instead.
 	ProxyProtocol *ProxyProtocol `json:"proxyProtocol,omitempty" toml:"proxyProtocol,omitempty" yaml:"proxyProtocol,omitempty" label:"allowEmpty" file:"allowEmpty" kv:"allowEmpty" export:"true"`
 	// TerminationDelay, corresponds to the deadline that the proxy sets, after one
@@ -95,6 +96,7 @@ type TCPServersLoadBalancer struct {
 	// connection, to close the reading capability as well, hence fully terminating the
 	// connection. It is a duration in milliseconds, defaulting to 100. A negative value
 	// means an infinite deadline (i.e. the reading capability is never closed).
+	//
 	// Deprecated: use ServersTransport to configure the TerminationDelay instead.
 	TerminationDelay *int                  `json:"terminationDelay,omitempty" toml:"terminationDelay,omitempty" yaml:"terminationDelay,omitempty" export:"true"`
 	HealthCheck      *TCPServerHealthCheck `json:"healthCheck,omitempty" toml:"healthCheck,omitempty" yaml:"healthCheck,omitempty" label:"allowEmpty" file:"allowEmpty" kv:"allowEmpty" export:"true"`

pkg/config/dynamic/tcp_middlewares.go

@@ -26,6 +26,7 @@ type TCPInFlightConn struct {
 // +k8s:deepcopy-gen=true
 
 // TCPIPWhiteList holds the TCP IPWhiteList middleware configuration.
+//
 // Deprecated: please use IPAllowList instead.
 type TCPIPWhiteList struct {
 	// SourceRange defines the allowed IPs (or ranges of allowed IPs by using CIDR notation).

pkg/config/kv/kv.go

@@ -13,7 +13,7 @@ import (
 // KV pairs -> tree of untyped nodes
 // untyped nodes -> nodes augmented with metadata such as kind (inferred from element)
 // "typed" nodes -> typed element.
-func Decode(pairs []*store.KVPair, element interface{}, rootName string) error {
+func Decode(pairs []*store.KVPair, element any, rootName string) error {
 	if element == nil {
 		return nil
 	}
@@ -34,7 +34,7 @@ func Decode(pairs []*store.KVPair, element interface{}, rootName string) error {
 	return parser.Fill(element, node, parser.FillerOpts{AllowSliceAsStruct: false})
 }
 
-func getRootFieldNames(rootName string, element interface{}) []string {
+func getRootFieldNames(rootName string, element any) []string {
 	if element == nil {
 		return nil
 	}

pkg/config/label/label.go

@@ -31,6 +31,6 @@ func EncodeConfiguration(conf *dynamic.Configuration) (map[string]string, error)
 
 // Decode converts the labels to an element.
 // labels -> [ node -> node + metadata (type) ] -> element (node).
-func Decode(labels map[string]string, element interface{}, filters ...string) error {
+func Decode(labels map[string]string, element any, filters ...string) error {
 	return parser.Decode(labels, element, parser.DefaultRootName, filters...)
 }

pkg/config/runtime/runtime_http.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"maps"
 	"slices"
 	"sort"
 	"sync"
@@ -74,6 +75,7 @@ func unique(src []string) []string {
 // RouterInfo holds information about a currently running HTTP router.
 type RouterInfo struct {
 	*dynamic.Router // dynamic configuration
+
 	// Err contains all the errors that occurred during router's creation.
 	Err []string `json:"error,omitempty"`
 	// Status reports whether the router is disabled, in a warning state, or all good (enabled).
@@ -91,10 +93,8 @@ type RouterInfo struct {
 // AddError adds err to r.Err, if it does not already exist.
 // If critical is set, r is marked as disabled.
 func (r *RouterInfo) AddError(err error, critical bool) {
-	for _, value := range r.Err {
+	if slices.Contains(r.Err, err.Error()) {
-		if value == err.Error() {
+		return
-			return
-		}
 	}
 
 	r.Err = append(r.Err, err.Error())
@@ -112,6 +112,7 @@ func (r *RouterInfo) AddError(err error, critical bool) {
 // MiddlewareInfo holds information about a currently running middleware.
 type MiddlewareInfo struct {
 	*dynamic.Middleware // dynamic configuration
+
 	// Err contains all the errors that occurred during service creation.
 	Err    []string `json:"error,omitempty"`
 	Status string   `json:"status,omitempty"`
@@ -121,10 +122,8 @@ type MiddlewareInfo struct {
 // AddError adds err to s.Err, if it does not already exist.
 // If critical is set, m is marked as disabled.
 func (m *MiddlewareInfo) AddError(err error, critical bool) {
-	for _, value := range m.Err {
+	if slices.Contains(m.Err, err.Error()) {
-		if value == err.Error() {
+		return
-			return
-		}
 	}
 
 	m.Err = append(m.Err, err.Error())
@@ -142,6 +141,7 @@ func (m *MiddlewareInfo) AddError(err error, critical bool) {
 // ServiceInfo holds information about a currently running service.
 type ServiceInfo struct {
 	*dynamic.Service // dynamic configuration
+
 	// Err contains all the errors that occurred during service creation.
 	Err []string `json:"error,omitempty"`
 	// Status reports whether the service is disabled, in a warning state, or all good (enabled).
@@ -157,10 +157,8 @@ type ServiceInfo struct {
 // AddError adds err to s.Err, if it does not already exist.
 // If critical is set, s is marked as disabled.
 func (s *ServiceInfo) AddError(err error, critical bool) {
-	for _, value := range s.Err {
+	if slices.Contains(s.Err, err.Error()) {
-		if value == err.Error() {
+		return
-			return
-		}
 	}
 
 	s.Err = append(s.Err, err.Error())
@@ -197,9 +195,5 @@ func (s *ServiceInfo) GetAllStatus() map[string]string {
 		return nil
 	}
 
-	allStatus := make(map[string]string, len(s.serverStatus))
+	return maps.Clone(s.serverStatus)
-	for k, v := range s.serverStatus {
-		allStatus[k] = v
-	}
-	return allStatus
 }

pkg/config/runtime/runtime_tcp.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"maps"
 	"slices"
 	"sync"
 
@@ -49,8 +50,9 @@ func (c *Configuration) GetTCPRoutersByEntryPoints(ctx context.Context, entryPoi
 
 // TCPRouterInfo holds information about a currently running TCP router.
 type TCPRouterInfo struct {
-	*dynamic.TCPRouter          // dynamic configuration
+	*dynamic.TCPRouter // dynamic configuration
-	Err                []string `json:"error,omitempty"` // initialization error
+
+	Err []string `json:"error,omitempty"` // initialization error
 	// Status reports whether the router is disabled, in a warning state, or all good (enabled).
 	// If not in "enabled" state, the reason for it should be in the list of Err.
 	// It is the caller's responsibility to set the initial status.
@@ -61,10 +63,8 @@ type TCPRouterInfo struct {
 // AddError adds err to r.Err, if it does not already exist.
 // If critical is set, r is marked as disabled.
 func (r *TCPRouterInfo) AddError(err error, critical bool) {
-	for _, value := range r.Err {
+	if slices.Contains(r.Err, err.Error()) {
-		if value == err.Error() {
+		return
-			return
-		}
 	}
 
 	r.Err = append(r.Err, err.Error())
@@ -81,8 +81,9 @@ func (r *TCPRouterInfo) AddError(err error, critical bool) {
 
 // TCPServiceInfo holds information about a currently running TCP service.
 type TCPServiceInfo struct {
-	*dynamic.TCPService          // dynamic configuration
+	*dynamic.TCPService // dynamic configuration
-	Err                 []string `json:"error,omitempty"` // initialization error
+
+	Err []string `json:"error,omitempty"` // initialization error
 	// Status reports whether the service is disabled, in a warning state, or all good (enabled).
 	// If not in "enabled" state, the reason for it should be in the list of Err.
 	// It is the caller's responsibility to set the initial status.
@@ -96,10 +97,8 @@ type TCPServiceInfo struct {
 // AddError adds err to s.Err, if it does not already exist.
 // If critical is set, s is marked as disabled.
 func (s *TCPServiceInfo) AddError(err error, critical bool) {
-	for _, value := range s.Err {
+	if slices.Contains(s.Err, err.Error()) {
-		if value == err.Error() {
+		return
-			return
-		}
 	}
 
 	s.Err = append(s.Err, err.Error())
@@ -135,15 +134,14 @@ func (s *TCPServiceInfo) GetAllStatus() map[string]string {
 	}
 
 	allStatus := make(map[string]string, len(s.serverStatus))
-	for k, v := range s.serverStatus {
+	maps.Copy(allStatus, s.serverStatus)
-		allStatus[k] = v
-	}
 	return allStatus
 }
 
 // TCPMiddlewareInfo holds information about a currently running middleware.
 type TCPMiddlewareInfo struct {
 	*dynamic.TCPMiddleware // dynamic configuration
+
 	// Err contains all the errors that occurred during service creation.
 	Err    []string `json:"error,omitempty"`
 	Status string   `json:"status,omitempty"`
@@ -153,10 +151,8 @@ type TCPMiddlewareInfo struct {
 // AddError adds err to s.Err, if it does not already exist.
 // If critical is set, m is marked as disabled.
 func (m *TCPMiddlewareInfo) AddError(err error, critical bool) {
-	for _, value := range m.Err {
+	if slices.Contains(m.Err, err.Error()) {
-		if value == err.Error() {
+		return
-			return
-		}
 	}
 
 	m.Err = append(m.Err, err.Error())

pkg/config/runtime/runtime_udp.go

@@ -54,8 +54,9 @@ func (c *Configuration) GetUDPRoutersByEntryPoints(ctx context.Context, entryPoi
 
 // UDPRouterInfo holds information about a currently running UDP router.
 type UDPRouterInfo struct {
-	*dynamic.UDPRouter          // dynamic configuration
+	*dynamic.UDPRouter // dynamic configuration
-	Err                []string `json:"error,omitempty"` // initialization error
+
+	Err []string `json:"error,omitempty"` // initialization error
 	// Status reports whether the router is disabled, in a warning state, or all good (enabled).
 	// If not in "enabled" state, the reason for it should be in the list of Err.
 	// It is the caller's responsibility to set the initial status.
@@ -66,10 +67,8 @@ type UDPRouterInfo struct {
 // AddError adds err to r.Err, if it does not already exist.
 // If critical is set, r is marked as disabled.
 func (r *UDPRouterInfo) AddError(err error, critical bool) {
-	for _, value := range r.Err {
+	if slices.Contains(r.Err, err.Error()) {
-		if value == err.Error() {
+		return
-			return
-		}
 	}
 
 	r.Err = append(r.Err, err.Error())
@@ -86,8 +85,9 @@ func (r *UDPRouterInfo) AddError(err error, critical bool) {
 
 // UDPServiceInfo holds information about a currently running UDP service.
 type UDPServiceInfo struct {
-	*dynamic.UDPService          // dynamic configuration
+	*dynamic.UDPService // dynamic configuration
-	Err                 []string `json:"error,omitempty"` // initialization error
+
+	Err []string `json:"error,omitempty"` // initialization error
 	// Status reports whether the service is disabled, in a warning state, or all good (enabled).
 	// If not in "enabled" state, the reason for it should be in the list of Err.
 	// It is the caller's responsibility to set the initial status.
@@ -98,10 +98,8 @@ type UDPServiceInfo struct {
 // AddError adds err to s.Err, if it does not already exist.
 // If critical is set, s is marked as disabled.
 func (s *UDPServiceInfo) AddError(err error, critical bool) {
-	for _, value := range s.Err {
+	if slices.Contains(s.Err, err.Error()) {
-		if value == err.Error() {
+		return
-			return
-		}
 	}
 
 	s.Err = append(s.Err, err.Error())

pkg/config/static/plugins.go

@@ -1,4 +1,4 @@
 package static
 
 // PluginConf holds the plugin configuration.
-type PluginConf map[string]interface{}
+type PluginConf map[string]any

pkg/config/static/static_config.go

@@ -393,21 +393,6 @@ func (c *Configuration) SetEffectiveConfiguration() {
 	c.initACMEProvider()
 }
 
-func (c *Configuration) hasUserDefinedEntrypoint() bool {
-	return len(c.EntryPoints) != 0
-}
-
-func (c *Configuration) initACMEProvider() {
-	for _, resolver := range c.CertificatesResolvers {
-		if resolver.ACME != nil {
-			resolver.ACME.CAServer = getSafeACMECAServer(resolver.ACME.CAServer)
-		}
-	}
-
-	logger := logs.NoLevel(log.Logger, zerolog.DebugLevel).With().Str("lib", "lego").Logger()
-	legolog.Logger = logs.NewLogrusWrapper(logger)
-}
-
 // ValidateConfiguration validate that configuration is coherent.
 func (c *Configuration) ValidateConfiguration() error {
 	for name, resolver := range c.CertificatesResolvers {
@@ -494,6 +479,21 @@ func (c *Configuration) ValidateConfiguration() error {
 	return nil
 }
 
+func (c *Configuration) hasUserDefinedEntrypoint() bool {
+	return len(c.EntryPoints) != 0
+}
+
+func (c *Configuration) initACMEProvider() {
+	for _, resolver := range c.CertificatesResolvers {
+		if resolver.ACME != nil {
+			resolver.ACME.CAServer = getSafeACMECAServer(resolver.ACME.CAServer)
+		}
+	}
+
+	logger := logs.NoLevel(log.Logger, zerolog.DebugLevel).With().Str("lib", "lego").Logger()
+	legolog.Logger = logs.NewLogrusWrapper(logger)
+}
+
 func getSafeACMECAServer(caServerSrc string) string {
 	if len(caServerSrc) == 0 {
 		return DefaultAcmeCAServer

pkg/healthcheck/healthcheck.go

@@ -391,7 +391,7 @@ func (p *PassiveServiceHealthChecker) WrapHandler(ctx context.Context, next http
 		}
 
 		// We need to guarantee that only one goroutine (request) will update the status and create a timer for the target.
-		_, _, _ = p.timersGroup.Do(targetURL, func() (interface{}, error) {
+		_, _, _ = p.timersGroup.Do(targetURL, func() (any, error) {
 			// A timer is already running for this target;
 			// it means that the target is already considered unhealthy.
 			if _, ok := p.timers.Load(targetURL); ok {

pkg/healthcheck/mock_test.go

@@ -165,6 +165,7 @@ type testLoadBalancer struct {
 	// RWMutex needed due to parallel test execution: Both the system-under-test
 	// and the test assertions reference the counters.
 	*sync.RWMutex
+
 	numRemovedServers  int
 	numUpsertedServers int
 }

pkg/job/job.go

@@ -17,6 +17,7 @@ const (
 // If operation() takes more than MinJobInterval, Reset() is called in NextBackOff().
 type BackOff struct {
 	*backoff.ExponentialBackOff
+
 	MinJobInterval time.Duration
 }
 

pkg/middlewares/accesslog/field_middleware_test.go

@@ -12,7 +12,7 @@ import (
 func TestConcatFieldHandler_ServeHTTP(t *testing.T) {
 	testCases := []struct {
 		desc           string
-		existingValue  interface{}
+		existingValue  any
 		newValue       string
 		expectedResult string
 	}{

pkg/middlewares/accesslog/logdata.go

@@ -129,7 +129,7 @@ func init() {
 }
 
 // CoreLogData holds the fields computed from the request/response.
-type CoreLogData map[string]interface{}
+type CoreLogData map[string]any
 
 // LogData is the data captured by the middleware so that it can be logged.
 type LogData struct {

pkg/middlewares/accesslog/logger.go

@@ -74,20 +74,6 @@ type Handler struct {
 	wg             sync.WaitGroup
 }
 
-// AliceConstructor returns an alice.Constructor that wraps the Handler (conditionally) in a middleware chain.
-func (h *Handler) AliceConstructor() alice.Constructor {
-	return func(next http.Handler) (http.Handler, error) {
-		return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
-			if h == nil {
-				next.ServeHTTP(rw, req)
-				return
-			}
-
-			h.ServeHTTP(rw, req, next)
-		}), nil
-	}
-}
-
 // NewHandler creates a new Handler.
 func NewHandler(ctx context.Context, config *otypes.AccessLog) (*Handler, error) {
 	var file io.WriteCloser = noopCloser{os.Stdout}
@@ -183,28 +169,18 @@ func NewHandler(ctx context.Context, config *otypes.AccessLog) (*Handler, error)
 	return logHandler, nil
 }
 
-func openAccessLogFile(filePath string) (*os.File, error) {
+// AliceConstructor returns an alice.Constructor that wraps the Handler (conditionally) in a middleware chain.
-	dir := filepath.Dir(filePath)
+func (h *Handler) AliceConstructor() alice.Constructor {
+	return func(next http.Handler) (http.Handler, error) {
+		return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+			if h == nil {
+				next.ServeHTTP(rw, req)
+				return
+			}
 
-	if err := os.MkdirAll(dir, 0o755); err != nil {
+			h.ServeHTTP(rw, req, next)
-		return nil, fmt.Errorf("failed to create log path %s: %w", dir, err)
+		}), nil
 	}
-
-	file, err := os.OpenFile(filePath, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0o664)
-	if err != nil {
-		return nil, fmt.Errorf("error opening file %s: %w", filePath, err)
-	}
-
-	return file, nil
-}
-
-// GetLogData gets the request context object that contains logging data.
-// This creates data as the request passes through the middleware chain.
-func GetLogData(req *http.Request) *LogData {
-	if ld, ok := req.Context().Value(DataTableKey).(*LogData); ok {
-		return ld
-	}
-	return nil
 }
 
 func (h *Handler) ServeHTTP(rw http.ResponseWriter, req *http.Request, next http.Handler) {
@@ -335,23 +311,6 @@ func (h *Handler) Rotate() error {
 	return nil
 }
 
-func silentSplitHostPort(value string) (host, port string) {
-	host, port, err := net.SplitHostPort(value)
-	if err != nil {
-		return value, "-"
-	}
-	return host, port
-}
-
-func usernameIfPresent(theURL *url.URL) string {
-	if theURL.User != nil {
-		if name := theURL.User.Username(); name != "" {
-			return name
-		}
-	}
-	return "-"
-}
-
 // Logging handler to log frontend name, backend name, and elapsed time.
 func (h *Handler) logTheRoundTrip(ctx context.Context, logDataTable *LogData) {
 	core := logDataTable.Core
@@ -458,6 +417,47 @@ func (h *Handler) keepAccessLog(statusCode, retryAttempts int, duration time.Dur
 	return false
 }
 
+// GetLogData gets the request context object that contains logging data.
+// This creates data as the request passes through the middleware chain.
+func GetLogData(req *http.Request) *LogData {
+	if ld, ok := req.Context().Value(DataTableKey).(*LogData); ok {
+		return ld
+	}
+	return nil
+}
+
+func openAccessLogFile(filePath string) (*os.File, error) {
+	dir := filepath.Dir(filePath)
+
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return nil, fmt.Errorf("failed to create log path %s: %w", dir, err)
+	}
+
+	file, err := os.OpenFile(filePath, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0o664)
+	if err != nil {
+		return nil, fmt.Errorf("error opening file %s: %w", filePath, err)
+	}
+
+	return file, nil
+}
+
+func silentSplitHostPort(value string) (host, port string) {
+	host, port, err := net.SplitHostPort(value)
+	if err != nil {
+		return value, "-"
+	}
+	return host, port
+}
+
+func usernameIfPresent(theURL *url.URL) string {
+	if theURL.User != nil {
+		if name := theURL.User.Username(); name != "" {
+			return name
+		}
+	}
+	return "-"
+}
+
 var requestCounter uint64 // Request ID
 
 func nextRequestCount() uint64 {

pkg/middlewares/accesslog/logger_formatters.go

@@ -81,7 +81,7 @@ func (f *GenericCLFLogFormatter) Format(entry *logrus.Entry) ([]byte, error) {
 	return b.Bytes(), err
 }
 
-func toLog(fields logrus.Fields, key, defaultValue string, quoted bool) interface{} {
+func toLog(fields logrus.Fields, key, defaultValue string, quoted bool) any {
 	if v, ok := fields[key]; ok {
 		if v == nil {
 			return defaultValue

pkg/middlewares/accesslog/logger_formatters_test.go

@@ -15,12 +15,12 @@ func TestCommonLogFormatter_Format(t *testing.T) {
 
 	testCases := []struct {
 		name        string
-		data        map[string]interface{}
+		data        map[string]any
 		expectedLog string
 	}{
 		{
 			name: "DownstreamStatus & DownstreamContentSize are nil",
-			data: map[string]interface{}{
+			data: map[string]any{
 				StartUTC:               time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC),
 				Duration:               123 * time.Second,
 				ClientHost:             "10.0.0.1",
@@ -41,7 +41,7 @@ func TestCommonLogFormatter_Format(t *testing.T) {
 		},
 		{
 			name: "all data",
-			data: map[string]interface{}{
+			data: map[string]any{
 				StartUTC:               time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC),
 				Duration:               123 * time.Second,
 				ClientHost:             "10.0.0.1",
@@ -62,7 +62,7 @@ func TestCommonLogFormatter_Format(t *testing.T) {
 		},
 		{
 			name: "all data with local time",
-			data: map[string]interface{}{
+			data: map[string]any{
 				StartLocal:             time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC),
 				Duration:               123 * time.Second,
 				ClientHost:             "10.0.0.1",
@@ -106,12 +106,12 @@ func TestGenericCLFLogFormatter_Format(t *testing.T) {
 
 	testCases := []struct {
 		name        string
-		data        map[string]interface{}
+		data        map[string]any
 		expectedLog string
 	}{
 		{
 			name: "DownstreamStatus & DownstreamContentSize are nil",
-			data: map[string]interface{}{
+			data: map[string]any{
 				StartUTC:               time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC),
 				Duration:               123 * time.Second,
 				ClientHost:             "10.0.0.1",
@@ -132,7 +132,7 @@ func TestGenericCLFLogFormatter_Format(t *testing.T) {
 		},
 		{
 			name: "all data",
-			data: map[string]interface{}{
+			data: map[string]any{
 				StartUTC:               time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC),
 				Duration:               123 * time.Second,
 				ClientHost:             "10.0.0.1",
@@ -153,7 +153,7 @@ func TestGenericCLFLogFormatter_Format(t *testing.T) {
 		},
 		{
 			name: "all data with local time",
-			data: map[string]interface{}{
+			data: map[string]any{
 				StartLocal:             time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC),
 				Duration:               123 * time.Second,
 				ClientHost:             "10.0.0.1",
@@ -199,7 +199,7 @@ func Test_toLog(t *testing.T) {
 		fieldName    string
 		defaultValue string
 		quoted       bool
-		expectedLog  interface{}
+		expectedLog  any
 	}{
 		{
 			desc: "Should return int 1",

pkg/middlewares/accesslog/logger_test.go

@@ -261,7 +261,7 @@ func lineCount(t *testing.T, fileName string) int {
 	}
 
 	count := 0
-	for _, line := range strings.Split(string(fileContents), "\n") {
+	for line := range strings.SplitSeq(string(fileContents), "\n") {
 		if strings.TrimSpace(line) == "" {
 			continue
 		}
@@ -439,32 +439,32 @@ func TestLoggerGenericCLFWithBufferingSize(t *testing.T) {
 	assertValidGenericCLFLogData(t, expectedLog, logData)
 }
 
-func assertString(exp string) func(t *testing.T, actual interface{}) {
+func assertString(exp string) func(t *testing.T, actual any) {
-	return func(t *testing.T, actual interface{}) {
+	return func(t *testing.T, actual any) {
 		t.Helper()
 
 		assert.Equal(t, exp, actual)
 	}
 }
 
-func assertNotEmpty() func(t *testing.T, actual interface{}) {
+func assertNotEmpty() func(t *testing.T, actual any) {
-	return func(t *testing.T, actual interface{}) {
+	return func(t *testing.T, actual any) {
 		t.Helper()
 
 		assert.NotEmpty(t, actual)
 	}
 }
 
-func assertFloat64(exp float64) func(t *testing.T, actual interface{}) {
+func assertFloat64(exp float64) func(t *testing.T, actual any) {
-	return func(t *testing.T, actual interface{}) {
+	return func(t *testing.T, actual any) {
 		t.Helper()
 
 		assert.InDelta(t, exp, actual, delta)
 	}
 }
 
-func assertFloat64NotZero() func(t *testing.T, actual interface{}) {
+func assertFloat64NotZero() func(t *testing.T, actual any) {
-	return func(t *testing.T, actual interface{}) {
+	return func(t *testing.T, actual any) {
 		t.Helper()
 
 		assert.NotZero(t, actual)
@@ -477,7 +477,7 @@ func TestLoggerJSON(t *testing.T) {
 		config   *otypes.AccessLog
 		tls      bool
 		tracing  bool
-		expected map[string]func(t *testing.T, value interface{})
+		expected map[string]func(t *testing.T, value any)
 	}{
 		{
 			desc: "default config without tracing",
@@ -485,7 +485,7 @@ func TestLoggerJSON(t *testing.T) {
 				FilePath: "",
 				Format:   JSONFormat,
 			},
-			expected: map[string]func(t *testing.T, value interface{}){
+			expected: map[string]func(t *testing.T, value any){
 				RequestContentSize:        assertFloat64(0),
 				RequestHost:               assertString(testHostname),
 				RequestAddr:               assertString(testHostname),
@@ -525,7 +525,7 @@ func TestLoggerJSON(t *testing.T) {
 				Format:   JSONFormat,
 			},
 			tracing: true,
-			expected: map[string]func(t *testing.T, value interface{}){
+			expected: map[string]func(t *testing.T, value any){
 				RequestContentSize:        assertFloat64(0),
 				RequestHost:               assertString(testHostname),
 				RequestAddr:               assertString(testHostname),
@@ -567,7 +567,7 @@ func TestLoggerJSON(t *testing.T) {
 				Format:   JSONFormat,
 			},
 			tls: true,
-			expected: map[string]func(t *testing.T, value interface{}){
+			expected: map[string]func(t *testing.T, value any){
 				RequestContentSize:        assertFloat64(0),
 				RequestHost:               assertString(testHostname),
 				RequestAddr:               assertString(testHostname),
@@ -612,7 +612,7 @@ func TestLoggerJSON(t *testing.T) {
 					DefaultMode: "drop",
 				},
 			},
-			expected: map[string]func(t *testing.T, value interface{}){
+			expected: map[string]func(t *testing.T, value any){
 				"level":                   assertString("info"),
 				"msg":                     assertString(""),
 				"time":                    assertNotEmpty(),
@@ -633,7 +633,7 @@ func TestLoggerJSON(t *testing.T) {
 					},
 				},
 			},
-			expected: map[string]func(t *testing.T, value interface{}){
+			expected: map[string]func(t *testing.T, value any){
 				"level": assertString("info"),
 				"msg":   assertString(""),
 				"time":  assertNotEmpty(),
@@ -651,7 +651,7 @@ func TestLoggerJSON(t *testing.T) {
 					},
 				},
 			},
-			expected: map[string]func(t *testing.T, value interface{}){
+			expected: map[string]func(t *testing.T, value any){
 				"level":                   assertString("info"),
 				"msg":                     assertString(""),
 				"time":                    assertNotEmpty(),
@@ -678,7 +678,7 @@ func TestLoggerJSON(t *testing.T) {
 					},
 				},
 			},
-			expected: map[string]func(t *testing.T, value interface{}){
+			expected: map[string]func(t *testing.T, value any){
 				RequestHost:          assertString(testHostname),
 				"level":              assertString("info"),
 				"msg":                assertString(""),
@@ -704,7 +704,7 @@ func TestLoggerJSON(t *testing.T) {
 					},
 				},
 			},
-			expected: map[string]func(t *testing.T, value interface{}){
+			expected: map[string]func(t *testing.T, value any){
 				RequestHost:          assertString(testHostname),
 				"level":              assertString("info"),
 				"msg":                assertString(""),
@@ -730,7 +730,7 @@ func TestLoggerJSON(t *testing.T) {
 			logData, err := os.ReadFile(logFilePath)
 			require.NoError(t, err)
 
-			jsonData := make(map[string]interface{})
+			jsonData := make(map[string]any)
 			err = json.Unmarshal(logData, &jsonData)
 			require.NoError(t, err)
 
@@ -744,7 +744,7 @@ func TestLoggerJSON(t *testing.T) {
 }
 
 func TestLogger_AbortedRequest(t *testing.T) {
-	expected := map[string]func(t *testing.T, value interface{}){
+	expected := map[string]func(t *testing.T, value any){
 		RequestContentSize:             assertFloat64(0),
 		RequestHost:                    assertString(testHostname),
 		RequestAddr:                    assertString(testHostname),
@@ -787,7 +787,7 @@ func TestLogger_AbortedRequest(t *testing.T) {
 	logData, err := os.ReadFile(config.FilePath)
 	require.NoError(t, err)
 
-	jsonData := make(map[string]interface{})
+	jsonData := make(map[string]any)
 	err = json.Unmarshal(logData, &jsonData)
 	require.NoError(t, err)
 

pkg/middlewares/auth/connectionheader.go

@@ -22,7 +22,7 @@ func RemoveConnectionHeaders(req *http.Request) {
 	}
 
 	for _, f := range req.Header[connectionHeader] {
-		for _, sf := range strings.Split(f, ",") {
+		for sf := range strings.SplitSeq(f, ",") {
 			if sf = textproto.TrimString(sf); sf != "" {
 				req.Header.Del(sf)
 			}

pkg/middlewares/capture/capture.go

@@ -96,20 +96,6 @@ func (c *Capture) Reset(next http.Handler) http.Handler {
 	})
 }
 
-func (c *Capture) renew(rw http.ResponseWriter, req *http.Request) (http.ResponseWriter, *http.Request) {
-	ctx := context.WithValue(req.Context(), capturedData, c)
-	newReq := req.WithContext(ctx)
-
-	if newReq.Body != nil {
-		readCounter := &readCounter{source: newReq.Body}
-		c.rr = readCounter
-		newReq.Body = readCounter
-	}
-	c.crw = &captureResponseWriter{rw: rw}
-
-	return c.crw, newReq
-}
-
 func (c *Capture) ResponseSize() int64 {
 	return c.crw.Size()
 }
@@ -127,6 +113,20 @@ func (c *Capture) RequestSize() int64 {
 	return c.rr.size
 }
 
+func (c *Capture) renew(rw http.ResponseWriter, req *http.Request) (http.ResponseWriter, *http.Request) {
+	ctx := context.WithValue(req.Context(), capturedData, c)
+	newReq := req.WithContext(ctx)
+
+	if newReq.Body != nil {
+		readCounter := &readCounter{source: newReq.Body}
+		c.rr = readCounter
+		newReq.Body = readCounter
+	}
+	c.crw = &captureResponseWriter{rw: rw}
+
+	return c.crw, newReq
+}
+
 type readCounter struct {
 	// source ReadCloser from where the request body is read.
 	source io.ReadCloser

pkg/middlewares/compress/acceptencoding.go

@@ -63,7 +63,7 @@ func parseAcceptableEncodings(acceptEncoding []string, supportedEncodings map[st
 	var encodings []Encoding
 
 	for _, line := range acceptEncoding {
-		for _, item := range strings.Split(strings.ReplaceAll(line, " ", ""), ",") {
+		for item := range strings.SplitSeq(strings.ReplaceAll(line, " ", ""), ",") {
 			parsed := strings.SplitN(item, ";", 2)
 			if len(parsed) == 0 {
 				continue

pkg/middlewares/compress/compress.go

@@ -167,6 +167,10 @@ func (c *compress) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	c.chooseHandler(c.getCompressionEncoding(acceptEncoding), rw, req)
 }
 
+func (c *compress) GetTracingInformation() (string, string) {
+	return c.name, typeName
+}
+
 func (c *compress) chooseHandler(typ string, rw http.ResponseWriter, req *http.Request) {
 	switch typ {
 	case zstdName:
@@ -180,10 +184,6 @@ func (c *compress) chooseHandler(typ string, rw http.ResponseWriter, req *http.R
 	}
 }
 
-func (c *compress) GetTracingInformation() (string, string) {
-	return c.name, typeName
-}
-
 func (c *compress) newGzipHandler() (http.Handler, error) {
 	var wrapper func(http.Handler) http.HandlerFunc
 	var err error

pkg/middlewares/compress/compression_handler.go

@@ -156,6 +156,7 @@ func (c *CompressionHandler) putCompressionWriter(writer *compressionWriterWrapp
 
 type compressionWriterWrapper struct {
 	CompressionWriter
+
 	algo string
 }
 

pkg/middlewares/compress/compression_handler_test.go

@@ -874,10 +874,7 @@ func Test_FlushExcludedContentTypes(t *testing.T) {
 				for len(tb) > 0 {
 					// Write 100 bytes per run
 					// Detection should not be affected (we send 100 bytes)
-					toWrite := 100
+					toWrite := min(100, len(tb))
-					if toWrite > len(tb) {
-						toWrite = len(tb)
-					}
 
 					_, err := rw.Write(tb[:toWrite])
 					require.NoError(t, err)
@@ -998,10 +995,7 @@ func Test_FlushIncludedContentTypes(t *testing.T) {
 				for len(tb) > 0 {
 					// Write 100 bytes per run
 					// Detection should not be affected (we send 100 bytes)
-					toWrite := 100
+					toWrite := min(100, len(tb))
-					if toWrite > len(tb) {
-						toWrite = len(tb)
-					}
 
 					_, err := rw.Write(tb[:toWrite])
 					require.NoError(t, err)

pkg/middlewares/customerrors/custom_errors.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"context"
 	"fmt"
+	"maps"
 	"net"
 	"net/http"
 	"net/url"
@@ -198,16 +199,6 @@ func (cc *codeCatcher) Header() http.Header {
 	return cc.headerMap
 }
 
-func (cc *codeCatcher) getCode() int {
-	return cc.code
-}
-
-// isFilteredCode returns whether the codeCatcher received a response code among the ones it is watching,
-// and for which the response should be deferred to the error handler.
-func (cc *codeCatcher) isFilteredCode() bool {
-	return cc.caughtFilteredCode
-}
-
 func (cc *codeCatcher) Write(buf []byte) (int, error) {
 	// If WriteHeader was already called from the caller, this is a NOOP.
 	// Otherwise, cc.code is actually a 200 here.
@@ -233,9 +224,7 @@ func (cc *codeCatcher) WriteHeader(code int) {
 	if code >= 100 && code <= 199 {
 		// Multiple informational status codes can be used,
 		// so here the copy is not appending the values to not repeat them.
-		for k, v := range cc.Header() {
+		maps.Copy(cc.responseWriter.Header(), cc.Header())
-			cc.responseWriter.Header()[k] = v
-		}
 
 		cc.responseWriter.WriteHeader(code)
 		return
@@ -253,9 +242,8 @@ func (cc *codeCatcher) WriteHeader(code int) {
 
 	// The copy is not appending the values,
 	// to not repeat them in case any informational status code has been written.
-	for k, v := range cc.Header() {
+	maps.Copy(cc.responseWriter.Header(), cc.Header())
-		cc.responseWriter.Header()[k] = v
+
-	}
 	cc.responseWriter.WriteHeader(cc.code)
 	cc.headersSent = true
 }
@@ -288,6 +276,16 @@ func (cc *codeCatcher) Flush() {
 	}
 }
 
+func (cc *codeCatcher) getCode() int {
+	return cc.code
+}
+
+// isFilteredCode returns whether the codeCatcher received a response code among the ones it is watching,
+// and for which the response should be deferred to the error handler.
+func (cc *codeCatcher) isFilteredCode() bool {
+	return cc.caughtFilteredCode
+}
+
 // codeModifier forwards a response back to the client,
 // while enforcing a given response code.
 type codeModifier struct {
@@ -343,17 +341,14 @@ func (r *codeModifier) WriteHeader(code int) {
 	if code >= 100 && code <= 199 {
 		// Multiple informational status codes can be used,
 		// so here the copy is not appending the values to not repeat them.
-		for k, v := range r.headerMap {
+		maps.Copy(r.responseWriter.Header(), r.headerMap)
-			r.responseWriter.Header()[k] = v
-		}
 
 		r.responseWriter.WriteHeader(code)
 		return
 	}
 
-	for k, v := range r.headerMap {
+	maps.Copy(r.responseWriter.Header(), r.headerMap)
-		r.responseWriter.Header()[k] = v
+
-	}
 	r.responseWriter.WriteHeader(r.code)
 	r.headerSent = true
 }

pkg/middlewares/forwardedheaders/forwarded_header.go

@@ -81,18 +81,11 @@ func NewXForwarded(insecure bool, trustedIPs []string, connectionHeaders []strin
 	}, nil
 }
 
-func (x *XForwarded) isTrustedIP(ip string) bool {
-	if x.ipChecker == nil {
-		return false
-	}
-	return x.ipChecker.IsAuthorized(ip) == nil
-}
-
 // removeIPv6Zone removes the zone if the given IP is an ipv6 address and it has {zone} information in it,
 // like "[fe80::d806:a55d:eb1b:49cc%vEthernet (vmxnet3 Ethernet Adapter - Virtual Switch)]:64692".
 func removeIPv6Zone(clientIP string) string {
-	if idx := strings.Index(clientIP, "%"); idx != -1 {
+	if before, _, found := strings.Cut(clientIP, "%"); found {
-		return clientIP[:idx]
+		return before
 	}
 	return clientIP
 }
@@ -138,6 +131,28 @@ func forwardedPort(req *http.Request) string {
 	return "80"
 }
 
+// ServeHTTP implements http.Handler.
+func (x *XForwarded) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if !x.insecure && !x.isTrustedIP(r.RemoteAddr) {
+		for _, h := range xHeaders {
+			unsafeHeader(r.Header).Del(h)
+		}
+	}
+
+	x.rewrite(r)
+
+	x.removeConnectionHeaders(r)
+
+	x.next.ServeHTTP(w, r)
+}
+
+func (x *XForwarded) isTrustedIP(ip string) bool {
+	if x.ipChecker == nil {
+		return false
+	}
+	return x.ipChecker.IsAuthorized(ip) == nil
+}
+
 func (x *XForwarded) rewrite(outreq *http.Request) {
 	if clientIP, _, err := net.SplitHostPort(outreq.RemoteAddr); err == nil {
 		clientIP = removeIPv6Zone(clientIP)
@@ -186,21 +201,6 @@ func (x *XForwarded) rewrite(outreq *http.Request) {
 	}
 }
 
-// ServeHTTP implements http.Handler.
-func (x *XForwarded) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	if !x.insecure && !x.isTrustedIP(r.RemoteAddr) {
-		for _, h := range xHeaders {
-			unsafeHeader(r.Header).Del(h)
-		}
-	}
-
-	x.rewrite(r)
-
-	x.removeConnectionHeaders(r)
-
-	x.next.ServeHTTP(w, r)
-}
-
 func (x *XForwarded) removeConnectionHeaders(req *http.Request) {
 	var reqUpType string
 	if httpguts.HeaderValuesContainsToken(req.Header[connection], upgrade) {
@@ -209,7 +209,7 @@ func (x *XForwarded) removeConnectionHeaders(req *http.Request) {
 
 	var connectionHopByHopHeaders []string
 	for _, f := range req.Header[connection] {
-		for _, sf := range strings.Split(f, ",") {
+		for sf := range strings.SplitSeq(f, ",") {
 			if sf = textproto.TrimString(sf); sf != "" {
 				// Connection header cannot dictate to remove X- headers managed by Traefik,
 				// as per rfc7230 https://datatracker.ietf.org/doc/html/rfc7230#section-6.1,

pkg/middlewares/gatewayapi/headermodifier/request_header_modifier_test.go

@@ -1,6 +1,7 @@
 package headermodifier
 
 import (
+	"maps"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -105,9 +106,7 @@ func TestRequestHeaderModifier(t *testing.T) {
 			handler := NewRequestHeaderModifier(t.Context(), next, test.config, "foo-request-header-modifier")
 
 			req := testhelpers.MustNewRequest(http.MethodGet, "http://localhost", nil)
-			for h, v := range test.requestHeaders {
+			maps.Copy(req.Header, test.requestHeaders)
-				req.Header[h] = v
-			}
 			resp := httptest.NewRecorder()
 
 			handler.ServeHTTP(resp, req)

pkg/middlewares/gatewayapi/headermodifier/response_header_modifier_test.go

@@ -1,6 +1,7 @@
 package headermodifier
 
 import (
+	"maps"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -107,9 +108,7 @@ func TestResponseHeaderModifier(t *testing.T) {
 
 			req := testhelpers.MustNewRequest(http.MethodGet, "http://localhost", nil)
 			resp := httptest.NewRecorder()
-			for k, v := range test.responseHeaders {
+			maps.Copy(resp.Header(), test.responseHeaders)
-				resp.Header()[k] = v
-			}
 
 			handler.ServeHTTP(resp, req)
 

pkg/middlewares/headers/header.go

@@ -64,27 +64,6 @@ func (s *Header) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	}
 }
 
-// modifyCustomRequestHeaders sets or deletes custom request headers.
-func (s *Header) modifyCustomRequestHeaders(req *http.Request) {
-	// Loop through Custom request headers
-	for header, value := range s.headers.CustomRequestHeaders {
-		switch {
-		// Handling https://github.com/golang/go/commit/ecdbffd4ec68b509998792f120868fec319de59b.
-		case value == "" && header == forward.XForwardedFor:
-			req.Header[header] = nil
-
-		case value == "":
-			req.Header.Del(header)
-
-		case strings.EqualFold(header, "Host"):
-			req.Host = value
-
-		default:
-			req.Header.Set(header, value)
-		}
-	}
-}
-
 // PostRequestModifyResponseHeaders set or delete response headers.
 // This method is called AFTER the response is generated from the backend
 // and can merge/override headers from the backend response.
@@ -134,6 +113,27 @@ func (s *Header) PostRequestModifyResponseHeaders(res *http.Response) error {
 	return nil
 }
 
+// modifyCustomRequestHeaders sets or deletes custom request headers.
+func (s *Header) modifyCustomRequestHeaders(req *http.Request) {
+	// Loop through Custom request headers
+	for header, value := range s.headers.CustomRequestHeaders {
+		switch {
+		// Handling https://github.com/golang/go/commit/ecdbffd4ec68b509998792f120868fec319de59b.
+		case value == "" && header == forward.XForwardedFor:
+			req.Header[header] = nil
+
+		case value == "":
+			req.Header.Del(header)
+
+		case strings.EqualFold(header, "Host"):
+			req.Host = value
+
+		default:
+			req.Header.Set(header, value)
+		}
+	}
+}
+
 // processCorsHeaders processes the incoming request,
 // and returns if it is a preflight request.
 // If not a preflight, it handles the preRequestModifyCorsResponseHeaders.

pkg/middlewares/observability/observability.go

@@ -65,7 +65,7 @@ func DetailedTracingEnabled(ctx context.Context) bool {
 }
 
 // SetStatusErrorf flags the span as in error and log an event.
-func SetStatusErrorf(ctx context.Context, format string, args ...interface{}) {
+func SetStatusErrorf(ctx context.Context, format string, args ...any) {
 	if span := trace.SpanFromContext(ctx); span != nil {
 		span.SetStatus(codes.Error, fmt.Sprintf(format, args...))
 	}

pkg/middlewares/observability/status_code.go

@@ -13,6 +13,7 @@ func newStatusCodeRecorder(rw http.ResponseWriter, status int) *statusCodeRecord
 
 type statusCodeRecorder struct {
 	http.ResponseWriter
+
 	status int
 }
 

pkg/middlewares/ratelimiter/lua.go

@@ -7,14 +7,14 @@ import (
 )
 
 type Rediser interface {
-	Eval(ctx context.Context, script string, keys []string, args ...interface{}) *redis.Cmd
+	Eval(ctx context.Context, script string, keys []string, args ...any) *redis.Cmd
-	EvalSha(ctx context.Context, sha1 string, keys []string, args ...interface{}) *redis.Cmd
+	EvalSha(ctx context.Context, sha1 string, keys []string, args ...any) *redis.Cmd
 	ScriptExists(ctx context.Context, hashes ...string) *redis.BoolSliceCmd
 	ScriptLoad(ctx context.Context, script string) *redis.StringCmd
 	Del(ctx context.Context, keys ...string) *redis.IntCmd
 
-	EvalRO(ctx context.Context, script string, keys []string, args ...interface{}) *redis.Cmd
+	EvalRO(ctx context.Context, script string, keys []string, args ...any) *redis.Cmd
-	EvalShaRO(ctx context.Context, sha1 string, keys []string, args ...interface{}) *redis.Cmd
+	EvalShaRO(ctx context.Context, sha1 string, keys []string, args ...any) *redis.Cmd
 }
 
 //nolint:dupword

pkg/middlewares/ratelimiter/rate_limiter.go

@@ -61,10 +61,7 @@ func New(ctx context.Context, next http.Handler, config dynamic.RateLimit, name
 		return nil, fmt.Errorf("getting source extractor: %w", err)
 	}
 
-	burst := config.Burst
+	burst := max(config.Burst, 1)
-	if burst < 1 {
-		burst = 1
-	}
 
 	period := time.Duration(config.Period)
 	if period < 0 {

pkg/middlewares/ratelimiter/rate_limiter_test.go

@@ -300,11 +300,8 @@ func TestInMemoryRateLimit(t *testing.T) {
 			stop := time.Now()
 			elapsed := stop.Sub(start)
 
-			burst := test.config.Burst
+			// actual default value if burst < 1
-			if burst < 1 {
+			burst := max(test.config.Burst, 1)
-				// actual default value
-				burst = 1
-			}
 
 			period := time.Duration(test.config.Period)
 			if period == 0 {
@@ -510,11 +507,8 @@ func TestRedisRateLimit(t *testing.T) {
 			stop := time.Now()
 			elapsed := stop.Sub(start)
 
-			burst := test.config.Burst
+			// actual default value
-			if burst < 1 {
+			burst := max(test.config.Burst, 1)
-				// actual default value
-				burst = 1
-			}
 
 			period := time.Duration(test.config.Period)
 			if period == 0 {
@@ -570,7 +564,7 @@ func newMockRedisClient(ttl int) Rediser {
 	}
 }
 
-func (m *mockRedisClient) EvalSha(ctx context.Context, _ string, keys []string, args ...interface{}) *redis.Cmd {
+func (m *mockRedisClient) EvalSha(ctx context.Context, _ string, keys []string, args ...any) *redis.Cmd {
 	state := lua.NewState()
 	defer state.Close()
 
@@ -641,7 +635,7 @@ func (m *mockRedisClient) EvalSha(ctx context.Context, _ string, keys []string,
 		return cmd
 	}
 
-	var resultSlice []interface{}
+	var resultSlice []any
 	resultTable.ForEach(func(_ lua.LValue, value lua.LValue) {
 		valueNbr, ok := value.(lua.LNumber)
 		if !ok {
@@ -661,7 +655,7 @@ func (m *mockRedisClient) EvalSha(ctx context.Context, _ string, keys []string,
 	return cmd
 }
 
-func (m *mockRedisClient) Eval(ctx context.Context, script string, keys []string, args ...interface{}) *redis.Cmd {
+func (m *mockRedisClient) Eval(ctx context.Context, script string, keys []string, args ...any) *redis.Cmd {
 	return m.EvalSha(ctx, script, keys, args...)
 }
 
@@ -677,11 +671,11 @@ func (m *mockRedisClient) Del(ctx context.Context, keys ...string) *redis.IntCmd
 	return nil
 }
 
-func (m *mockRedisClient) EvalRO(ctx context.Context, script string, keys []string, args ...interface{}) *redis.Cmd {
+func (m *mockRedisClient) EvalRO(ctx context.Context, script string, keys []string, args ...any) *redis.Cmd {
 	return nil
 }
 
-func (m *mockRedisClient) EvalShaRO(ctx context.Context, sha1 string, keys []string, args ...interface{}) *redis.Cmd {
+func (m *mockRedisClient) EvalShaRO(ctx context.Context, sha1 string, keys []string, args ...any) *redis.Cmd {
 	return nil
 }
 

pkg/middlewares/ratelimiter/redis_limiter.go

@@ -91,7 +91,7 @@ func (r *redisLimiter) evaluateScript(ctx context.Context, key string) (bool, *t
 		return true, nil, nil
 	}
 
-	params := []interface{}{
+	params := []any{
 		float64(r.rate / 1000000),
 		r.burst,
 		r.ttl,
@@ -103,7 +103,7 @@ func (r *redisLimiter) evaluateScript(ctx context.Context, key string) (bool, *t
 		return false, nil, fmt.Errorf("running script: %w", err)
 	}
 
-	values := v.([]interface{})
+	values := v.([]any)
 	ok, err := strconv.ParseBool(values[0].(string))
 	if err != nil {
 		return false, nil, fmt.Errorf("parsing ok value from redis rate lua script: %w", err)

pkg/middlewares/recovery/recovery.go

@@ -56,7 +56,7 @@ func recoverFunc(rw recoveryResponseWriter, req *http.Request) {
 
 // https://github.com/golang/go/blob/a0d6420d8be2ae7164797051ec74fa2a2df466a1/src/net/http/server.go#L1761-L1775
 // https://github.com/golang/go/blob/c33153f7b416c03983324b3e8f869ce1116d84bc/src/net/http/httputil/reverseproxy.go#L284
-func shouldLogPanic(panicValue interface{}) bool {
+func shouldLogPanic(panicValue any) bool {
 	//nolint:errorlint // false-positive because panicValue is an interface.
 	return panicValue != nil && panicValue != http.ErrAbortHandler
 }

pkg/middlewares/retry/retry.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"maps"
 	"math"
 	"net"
 	"net/http"
@@ -249,10 +250,7 @@ func (r *responseWriter) WriteHeader(code int) {
 	// to write headers to the backend : we are not going to perform any further retry.
 	// So it is now safe to alter current response headers with headers collected during
 	// the latest try before writing headers to client.
-	headers := r.responseWriter.Header()
+	maps.Copy(r.responseWriter.Header(), r.headers)
-	for header, value := range r.headers {
-		headers[header] = value
-	}
 
 	r.responseWriter.WriteHeader(code)
 

pkg/muxer/http/matcher.go

@@ -184,13 +184,7 @@ func header(tree *matchersTree, headers ...string) error {
 	key, value := http.CanonicalHeaderKey(headers[0]), headers[1]
 
 	tree.matcher = func(req *http.Request) bool {
-		for _, headerValue := range req.Header[key] {
+		return slices.Contains(req.Header[key], value)
-			if headerValue == value {
-				return true
-			}
-		}
-
-		return false
 	}
 
 	return nil
@@ -205,13 +199,7 @@ func headerRegexp(tree *matchersTree, headers ...string) error {
 	}
 
 	tree.matcher = func(req *http.Request) bool {
-		for _, headerValue := range req.Header[key] {
+		return slices.ContainsFunc(req.Header[key], re.MatchString)
-			if re.MatchString(headerValue) {
-				return true
-			}
-		}
-
-		return false
 	}
 
 	return nil

pkg/muxer/http/mux.go

@@ -22,7 +22,8 @@ type MatcherFunc func(*http.Request) bool
 
 // Muxer handles routing with rules.
 type Muxer struct {
-	routes         routes
+	routes routes
+
 	parser         SyntaxParser
 	defaultHandler http.Handler
 }

pkg/muxer/tcp/matcher.go

@@ -3,6 +3,7 @@ package tcp
 import (
 	"fmt"
 	"regexp"
+	"slices"
 	"strings"
 	"unicode/utf8"
 
@@ -37,13 +38,7 @@ func alpn(tree *matchersTree, protos ...string) error {
 	}
 
 	tree.matcher = func(meta ConnData) bool {
-		for _, alpnProto := range meta.alpnProtos {
+		return slices.Contains(meta.alpnProtos, proto)
-			if alpnProto == proto {
-				return true
-			}
-		}
-
-		return false
 	}
 
 	return nil

pkg/muxer/tcp/matcher_v2.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"regexp"
+	"slices"
 	"strconv"
 	"strings"
 
@@ -56,10 +57,8 @@ func alpnV2(tree *matchersTree, protos ...string) error {
 
 	tree.matcher = func(meta ConnData) bool {
 		for _, proto := range meta.alpnProtos {
-			for _, filter := range protos {
+			if slices.Contains(protos, proto) {
-				if proto == filter {
+				return true
-					return true
-				}
 			}
 		}
 

pkg/muxer/tcp/mux.go

@@ -121,7 +121,7 @@ func GetRulePriority(rule string) int {
 // AddRoute adds a new route, associated to the given handler, at the given
 // priority, to the muxer.
 func (m *Muxer) AddRoute(rule string, syntax string, priority int, handler tcp.Handler) error {
-	var parse interface{}
+	var parse any
 	var err error
 	var matcherFuncs map[string]func(*matchersTree, ...string) error
 

pkg/observability/logs/aws.go

@@ -7,10 +7,10 @@ import (
 
 func NewAWSWrapper(logger zerolog.Logger) logging.LoggerFunc {
 	if logger.GetLevel() > zerolog.DebugLevel {
-		return func(classification logging.Classification, format string, args ...interface{}) {}
+		return func(classification logging.Classification, format string, args ...any) {}
 	}
 
-	return func(classification logging.Classification, format string, args ...interface{}) {
+	return func(classification logging.Classification, format string, args ...any) {
 		logger.Debug().CallerSkipFrame(2).MsgFunc(msgFunc(args...))
 	}
 }