chore: update linter.

pkg/middlewares/accesslog/capture_response_writer.go

@@ -9,9 +9,7 @@ import (
 	"github.com/containous/traefik/v2/pkg/middlewares"
 )
 
-var (
-	_ middlewares.Stateful = &captureResponseWriterWithCloseNotify{}
-)
+var _ middlewares.Stateful = &captureResponseWriterWithCloseNotify{}
 
 type capturer interface {
 	http.ResponseWriter

pkg/middlewares/accesslog/field_middleware.go

@@ -19,7 +19,7 @@ type FieldHandler struct {
 }
 
 // NewFieldHandler creates a Field handler.
-func NewFieldHandler(next http.Handler, name string, value string, applyFn FieldApply) http.Handler {
+func NewFieldHandler(next http.Handler, name, value string, applyFn FieldApply) http.Handler {
 	return &FieldHandler{next: next, name: name, value: value, applyFn: applyFn}
 }
 

pkg/middlewares/accesslog/logger.go

@@ -131,11 +131,11 @@ func NewHandler(config *types.AccessLog) (*Handler, error) {
 func openAccessLogFile(filePath string) (*os.File, error) {
 	dir := filepath.Dir(filePath)
 
-	if err := os.MkdirAll(dir, 0755); err != nil {
+	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, 0664)
+	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)
 	}
@@ -249,7 +249,7 @@ func (h *Handler) Rotate() error {
 	}
 
 	var err error
-	h.file, err = os.OpenFile(h.config.FilePath, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0664)
+	h.file, err = os.OpenFile(h.config.FilePath, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0o664)
 	if err != nil {
 		return err
 	}
@@ -259,7 +259,7 @@ func (h *Handler) Rotate() error {
 	return nil
 }
 
-func silentSplitHostPort(value string) (host string, port string) {
+func silentSplitHostPort(value string) (host, port string) {
 	host, port, err := net.SplitHostPort(value)
 	if err != nil {
 		return value, "-"

pkg/middlewares/accesslog/logger_formatters.go

@@ -21,7 +21,7 @@ type CommonLogFormatter struct{}
 func (f *CommonLogFormatter) Format(entry *logrus.Entry) ([]byte, error) {
 	b := &bytes.Buffer{}
 
-	var timestamp = defaultValue
+	timestamp := defaultValue
 	if v, ok := entry.Data[StartUTC]; ok {
 		timestamp = v.(time.Time).Format(commonLogTimeFormat)
 	} else if v, ok := entry.Data[StartLocal]; ok {
@@ -52,7 +52,7 @@ func (f *CommonLogFormatter) Format(entry *logrus.Entry) ([]byte, error) {
 	return b.Bytes(), err
 }
 
-func toLog(fields logrus.Fields, key string, defaultValue string, quoted bool) interface{} {
+func toLog(fields logrus.Fields, key, defaultValue string, quoted bool) interface{} {
 	if v, ok := fields[key]; ok {
 		if v == nil {
 			return defaultValue
@@ -73,7 +73,7 @@ func toLog(fields logrus.Fields, key string, defaultValue string, quoted bool) i
 	return defaultValue
 }
 
-func toLogEntry(s string, defaultValue string, quote bool) string {
+func toLogEntry(s, defaultValue string, quote bool) string {
 	if len(s) == 0 {
 		return defaultValue
 	}

pkg/middlewares/auth/forward.go

@@ -158,7 +158,7 @@ func (fa *forwardAuth) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	fa.next.ServeHTTP(rw, req)
 }
 
-func writeHeader(req *http.Request, forwardReq *http.Request, trustForwardHeader bool) {
+func writeHeader(req, forwardReq *http.Request, trustForwardHeader bool) {
 	utils.CopyHeaders(forwardReq.Header, req.Header)
 	utils.RemoveHeaders(forwardReq.Header, forward.HopHeaders...)
 

pkg/middlewares/auth/forward_test.go

@@ -325,7 +325,8 @@ func Test_writeHeader(t *testing.T) {
 				"X-Forwarded-Host": "foo.bar",
 				"X-Forwarded-Uri":  "/path?q=1",
 			},
-		}, {
+		},
+		{
 			name: "trust Forward Header with forwarded request Method",
 			headers: map[string]string{
 				"X-Forwarded-Method": "OPTIONS",

pkg/middlewares/forwardedheaders/forwarded_header_test.go

@@ -246,7 +246,8 @@ func TestServeHTTP(t *testing.T) {
 			expectedHeaders: map[string]string{
 				xForwardedHost: "foo.com:8080",
 			},
-		}, {
+		},
+		{
 			desc: "xForwardedServer from req XForwarded",
 			host: "foo.com:8080",
 			expectedHeaders: map[string]string{

pkg/middlewares/headers/headers_test.go

@@ -540,7 +540,8 @@ func TestCORSResponses(t *testing.T) {
 			expected: map[string][]string{
 				"Access-Control-Allow-Origin": {"*"},
 			},
-		}, {
+		},
+		{
 			desc: "Test Simple CustomRequestHeaders Not Hijacked by CORS",
 			header: NewHeader(emptyHandler, dynamic.Headers{
 				CustomRequestHeaders: map[string]string{"foo": "bar"},

pkg/middlewares/middleware.go

@@ -7,6 +7,6 @@ import (
 )
 
 // GetLoggerCtx creates a logger context with the middleware fields.
-func GetLoggerCtx(ctx context.Context, middleware string, middlewareType string) context.Context {
+func GetLoggerCtx(ctx context.Context, middleware, middlewareType string) context.Context {
 	return log.With(ctx, log.Str(log.MiddlewareName, middleware), log.Str(log.MiddlewareType, middlewareType))
 }

pkg/middlewares/passtlsclientcert/pass_tls_client_cert.go

@@ -235,7 +235,7 @@ func writeParts(ctx context.Context, content io.StringWriter, entries []string,
 	}
 }
 
-func writePart(ctx context.Context, content io.StringWriter, entry string, prefix string) {
+func writePart(ctx context.Context, content io.StringWriter, entry, prefix string) {
 	if len(entry) > 0 {
 		_, err := content.WriteString(fmt.Sprintf("%s=%s%s", prefix, entry, subFieldSeparator))
 		if err != nil {

pkg/middlewares/redirect/redirect.go

@@ -24,7 +24,7 @@ type redirect struct {
 }
 
 // New creates a Redirect middleware.
-func newRedirect(next http.Handler, regex string, replacement string, permanent bool, name string) (http.Handler, error) {
+func newRedirect(next http.Handler, regex, replacement string, permanent bool, name string) (http.Handler, error) {
 	re, err := regexp.Compile(regex)
 	if err != nil {
 		return nil, err

pkg/middlewares/requestdecorator/hostresolver.go

@@ -47,7 +47,7 @@ func (hr *Resolver) CNAMEFlatten(ctx context.Context, host string) string {
 	}
 
 	logger := log.FromContext(ctx)
-	var cacheDuration = 0 * time.Second
+	cacheDuration := 0 * time.Second
 	for depth := 0; depth < hr.ResolvDepth; depth++ {
 		resolv, err := cnameResolve(ctx, request, hr.ResolvConfig)
 		if err != nil {
@@ -73,7 +73,7 @@ func (hr *Resolver) CNAMEFlatten(ctx context.Context, host string) string {
 }
 
 // cnameResolve resolves CNAME if exists, and return with the highest TTL.
-func cnameResolve(ctx context.Context, host string, resolvPath string) (*cnameResolv, error) {
+func cnameResolve(ctx context.Context, host, resolvPath string) (*cnameResolv, error) {
 	config, err := dns.ClientConfigFromFile(resolvPath)
 	if err != nil {
 		return nil, fmt.Errorf("invalid resolver configuration file: %s", resolvPath)
@@ -102,7 +102,7 @@ func cnameResolve(ctx context.Context, host string, resolvPath string) (*cnameRe
 	return result[0], nil
 }
 
-func getRecord(client *dns.Client, msg *dns.Msg, server string, port string) (*cnameResolv, error) {
+func getRecord(client *dns.Client, msg *dns.Msg, server, port string) (*cnameResolv, error) {
 	resp, _, err := client.Exchange(msg, net.JoinHostPort(server, port))
 	if err != nil {
 		return nil, fmt.Errorf("exchange error for server %s: %w", server, err)

pkg/middlewares/tracing/forwarder_test.go

@@ -45,7 +45,8 @@ func TestNewForwarder(t *testing.T) {
 				},
 				OperationName: "forward some-service.domain.tld/some-service.domain.tld",
 			},
-		}, {
+		},
+		{
 			desc:          "Simple Forward Tracer with truncation and hashing",
 			spanNameLimit: 101,
 			tracing: &trackingBackenMock{

pkg/middlewares/tracing/mock_tracing_test.go

@@ -18,12 +18,12 @@ func (n MockTracer) StartSpan(operationName string, opts ...opentracing.StartSpa
 }
 
 // Inject belongs to the Tracer interface.
-func (n MockTracer) Inject(sp opentracing.SpanContext, format interface{}, carrier interface{}) error {
+func (n MockTracer) Inject(sp opentracing.SpanContext, format, carrier interface{}) error {
 	return nil
 }
 
 // Extract belongs to the Tracer interface.
-func (n MockTracer) Extract(format interface{}, carrier interface{}) (opentracing.SpanContext, error) {
+func (n MockTracer) Extract(format, carrier interface{}) (opentracing.SpanContext, error) {
 	return nil, opentracing.ErrSpanContextNotFound
 }