[release-11.6.8] Log TLS handshake EOF error as DEBUG instead INFO (#113097)

Log TLS handshake EOF error as DEBUG instead INFO (#112294)

* Log TLS handshake EOF error as DEBUG instead INFO



---------


(cherry picked from commit a75b01907d)

Signed-off-by: Maicon Costa <maiconscosta@gmail.com>
Co-authored-by: maicon <maiconscosta@gmail.com>

pkg/api/http_server.go

@@ -12,6 +12,7 @@ import (
 	"encoding/pem"
 	"errors"
 	"fmt"
+	stdlog "log"
 	"math/big"
 	"net"
 	"net/http"
@@ -401,6 +402,26 @@ func (hs *HTTPServer) AddNamedMiddleware(middleware routing.RegisterNamedMiddlew
 	hs.namedMiddlewares = append(hs.namedMiddlewares, middleware)
 }
 
+type customErrorLogger struct {
+	log log.Logger
+}
+
+const tlsHandshakeErrorPrefix = "http: TLS handshake error from"
+const tlsHandshakeErrorSuffix = "EOF"
+
+func (w *customErrorLogger) Write(msg []byte) (int, error) {
+	// checks if the error is a TLS handshake error that ends with EOF
+	if strings.Contains(string(msg), tlsHandshakeErrorPrefix) && strings.Contains(string(msg), tlsHandshakeErrorSuffix) {
+		// log at debug level and remove new lines
+		w.log.Debug(strings.ReplaceAll(string(msg), "\n", ""))
+	} else {
+		// log the error as is using the standard logger (the same way as the default http server does)
+		stdlog.Print(string(msg))
+	}
+
+	return len(msg), nil
+}
+
 func (hs *HTTPServer) Run(ctx context.Context) error {
 	hs.context = ctx
 
@@ -413,6 +434,12 @@ func (hs *HTTPServer) Run(ctx context.Context) error {
 		Handler:     hs.web,
 		ReadTimeout: hs.Cfg.ReadTimeout,
 	}
+
+	customErrorLogger := &customErrorLogger{
+		log: hs.log,
+	}
+	hs.httpSrv.ErrorLog = stdlog.New(customErrorLogger, "", 0)
+
 	switch hs.Cfg.Protocol {
 	case setting.HTTP2Scheme, setting.HTTPSScheme:
 		if err := hs.configureTLS(); err != nil {