log: support to set output

Signed-off-by: ningmingxiao <ning.mingxiao@zte.com.cn>

Author: ningmingxiao

context.go

@@ -40,6 +40,7 @@ package log
 import (
 	"context"
 	"fmt"
+	"io"
 
 	"github.com/sirupsen/logrus"
 )
@@ -130,6 +131,10 @@ func SetLevel(level string) error {
 	return nil
 }
 
+func SetOutput(out io.Writer) {
+	L.Logger.SetOutput(out)
+}
+
 // GetLevel returns the current log level.
 func GetLevel() Level {
 	return L.Logger.GetLevel()