Rotation logs - How to add timestamp to log file name?

Below code for rotation logs:

package main
import (
	"os"
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
	lumberjack "gopkg.in/natefinch/lumberjack.v2"
)
func main() {
	logPath, _ := os.Getwd()
	log := NewLoggerFp(logPath, 1, 2, 2)
	log.Infof("sjkshfjsdf\n")
	log.Infof("sjkshfjsdf\n")
	log.Infof("sjkshfjsdf\n")
}
func NewLoggerFp(logPath string, maxSize, maxBackUp, maxAge int) *zap.SugaredLogger {
	w := zapcore.AddSync(&lumberjack.Logger{
		Filename:   logPath + "/dump.log",
		MaxSize:    maxSize, // megabytes
		MaxBackups: maxBackUp,
		MaxAge:     maxAge, // days
	})
	core := zapcore.NewCore(
		zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig()),
		w,
		zap.InfoLevel,
	)
	return zap.New(core).Sugar()
}

Logs get created
How to add timestamp to dump.log?

I try to understand what Christian suggests. Maybe you can try this.

w := zapcore.AddSync(&lumberjack.Logger{
	Filename:   logPath + fmt.Sprintf("/dump-%v.log", time.Now().Format(time.RFC822)),
	MaxSize:    maxSize, // megabytes
	MaxBackups: maxBackUp,
	MaxAge:     maxAge, // days
})

Have you tested it with a smaller MaxSize (or MaxAge) parameter?

According to https://pkg.go.dev/gopkg.in/natefinch/lumberjack.v2#example-Logger.Rotate, Lumberjack will append to the first file if the file exists and is less than MaxSize megabytes. When this limit is reached, timestamps are automatically added:

> Whenever a write would cause the current log file exceed MaxSize megabytes, the current file is closed, renamed, and a new log file created with the original name.
>
> Backups use the log file name given to Logger, in the form name-timestamp.ext where name is the filename without the extension, timestamp is the time at which the log was rotated formatted with the time.Time format of 2006-01-02T15-04-05.000 and the extension is the original extension.
>
> For example, if your Logger.Filename is /var/log/foo/server.log, a backup created at 6:30pm on Nov 11 2016 would use the filename /var/log/foo/server-2016-11-04T18-30-00.000.log
>
> If the file exists and its size is >= MaxSize megabytes, the file is renamed by putting the current time in a timestamp in the name immediately before the file's extension (or the end of the filename if there's no extension). A new log file is then created using original filename.

There is an open pull request to be able to customize the time stamp format: https://github.com/natefinch/lumberjack/pull/118