Go agent got the log but without content

[akilichen]

Hi, there, I'm using Kratos. Now I am using uber-go/zap to be the application logger.

I found that the go-agent got the logs in the console without any contents. By the way, the other features are fine.

Here are some messages for you guys, please help me find out my mistakes:

• Kratos: v2.7.2
• Agent: 0.5.0

// logger for Kratos
logger := log.With(zaplog.Logger())
...
...
//  zap log instance
type ZapLogger struct {
	log  *zap.Logger
	Sync func() error
}

// Logger 配置zap日志,将zap日志库引入
func Logger() log.Logger {
	//配置zap日志库的编码器
	encoder := zapcore.EncoderConfig{
		TimeKey:        "time",
		LevelKey:       "level",
		NameKey:        "logger",
		CallerKey:      "caller",
		MessageKey:     "company-service",
		StacktraceKey:  "stack",
		EncodeTime:     zapcore.ISO8601TimeEncoder,
		LineEnding:     zapcore.DefaultLineEnding,
		EncodeLevel:    zapcore.LowercaseLevelEncoder,
		EncodeDuration: zapcore.StringDurationEncoder,
		EncodeCaller:   zapcore.ShortCallerEncoder,
	}
	return NewZapLogger(
		encoder,
		zap.NewAtomicLevelAt(zapcore.DebugLevel),
		zap.AddStacktrace(zap.NewAtomicLevelAt(zapcore.ErrorLevel)),
		zap.AddCaller(),
		zap.AddCallerSkip(2),
		zap.Development(),
	)
}

// 日志自动切割，采用 lumberjack 实现的
func getLogWriter() zapcore.WriteSyncer {
	lumberJackLogger := &lumberjack.Logger{
		Filename:   "../../company-service.log",
		MaxSize:    100,  //日志的最大大小（M）
		MaxBackups: 10,   //日志的最大保存数量
		MaxAge:     30,   //日志文件存储最大天数
		Compress:   true, //是否执行压缩
	}
	return zapcore.AddSync(lumberJackLogger)
}

// NewZapLogger return a zap logger.
func NewZapLogger(encoder zapcore.EncoderConfig, level zap.AtomicLevel, opts ...zap.Option) *ZapLogger {
	//日志切割
	writeSyncer := getLogWriter()
	//设置日志级别
	level.SetLevel(zapcore.InfoLevel)
	var core zapcore.Core
	//开发模式下打印到标准输出
	// --根据配置文件判断输出到控制台还是日志文件--
	if os.Getenv("mode") != "prod" {
		core = zapcore.NewCore(
			zapcore.NewJSONEncoder(encoder), // 编码器配置
			zapcore.NewMultiWriteSyncer(zapcore.AddSync(os.Stdout), zapcore.AddSync(writeSyncer)), // 打印到控制台和文件
			level, // 日志级别
		)
	} else {
		core = zapcore.NewCore(
			zapcore.NewConsoleEncoder(encoder),                      // 编码器配置
			zapcore.NewMultiWriteSyncer(zapcore.AddSync(os.Stdout)), // 打印到控制台
			level, // 日志级别
		)
	}
	zapLogger := zap.New(core, opts...)
	return &ZapLogger{log: zapLogger, Sync: zapLogger.Sync}
}

// Log 实现log接口
func (l *ZapLogger) Log(level log.Level, keyvals ...interface{}) error {
	if len(keyvals) == 0 || len(keyvals)%2 != 0 {
		l.log.Warn(fmt.Sprint("Key Values must appear in pairs: ", keyvals))
		return nil
	}

	var data []zap.Field
	for i := 0; i < len(keyvals); i += 2 {
		data = append(data, zap.Any(fmt.Sprint(keyvals[i]), keyvals[i+1]))
	}

	switch level {
	case log.LevelDebug:
		l.log.Debug("", data...)
	case log.LevelInfo:
		l.log.Info("", data...)
	case log.LevelWarn:
		l.log.Warn("", data...)
	case log.LevelError:
		l.log.Error("", data...)
	case log.LevelFatal:
		l.log.Fatal("", data...)
	}
	return nil
}

Thanks for your time~

[akilichen]

@mrproliu Now I found that skywalking's log works, but the application's Zap log is still.

Is there a similar case in the community？

[akilichen]

Trying to understand your reply, I add a env param named company-service, but can't works.



If I got something wrong?

[mrproliu]

It's not related MessageKey in the encoder, It's related to your messages. As I mentioned, you have wrapper the logger, right? And your message content is always empty when using zap.log.Debug/Info/Warn/Error/Fatal. This is the problem.

If you want to add your key-value in the log label, you should add them. Such as, when you using the wrapped logger as following:

logger.Log(zap.LevelInfo, "test-key1", "test-value1", "test-key2", "test-value2")

If you want to show key-values in the UI, you should export them as following configuration:

export SW_AGENT_LOG_REPORTER_LABEL_KEYS="test-key1,test-key2"

[akilichen]

So If I use the zap.log as my logger wrapper, I can never get the logs in the “时间戳-内容”，right?
By the way, now I have export the SW_AGENT_LOG_REPORTER_LABEL_KEYS configuration like export SW_AGENT_LOG_REPORTER_LABEL_KEYS=msg, and got the logs in label format, thanks for this:

How can I do the next and get the logs preview in the “时间戳-内容”

[mrproliu]

The single way it makes your key-value data as the content, instant of empty string.

[akilichen]

ok, I will consider this suggestion. thanks again.