Prepend a prefix in every logs generated in the application #1290

meetme2meat · 2023-05-24T18:28:21Z

meetme2meat
May 24, 2023

I had set up the zap logger with following configuration

       outLevel := zap.LevelEnablerFunc(func(level zapcore.Level) bool {
		return level < zapcore.WarnLevel
	})

	// Warnings and everything above will be printed to stderr
	errorLevel := zap.LevelEnablerFunc(func(level zapcore.Level) bool {
		return level >= zapcore.WarnLevel
	})

	stdoutSyncer := zapcore.Lock(os.Stdout)
	stderrSyncer := zapcore.Lock(os.Stderr)

	config := zap.NewDevelopmentConfig()
	config.EncoderConfig.EncodeLevel = zapcore.CapitalLevelEncoder
	config.EncoderConfig.TimeKey = ""

	core := zapcore.NewTee(
		zapcore.NewCore(
			zapcore.NewConsoleEncoder(config.EncoderConfig),
			stdoutSyncer,
			outLevel,
		),
		zapcore.NewCore(
			zapcore.NewConsoleEncoder(config.EncoderConfig),
			stderrSyncer,
			errorLevel,
		),
	)

	logger := zap.New(core)

	zap.ReplaceGlobals(logger)

Help me understand if is it possible to prepend a prefix to every log message (DEBUG, INFO) something like what log library provides https://pkg.go.dev/log#SetPrefix

zap.L().Info("this is new message")

and the prefix is "=>"

The final log line would appear like this

"=> this is new message"

I tried with log.With API but it seems to create a new JSON object which is different from what I need.

stanislavkozlovski · 2024-09-20T21:37:22Z

stanislavkozlovski
Sep 20, 2024

weird this still isn't answered

0 replies

charles-braga-unvoid · 2024-11-01T11:35:38Z

charles-braga-unvoid
Nov 1, 2024

Did you try it? https://stackoverflow.com/questions/70489167/uber-zap-logger-how-to-prepend-every-log-entry-with-a-string

0 replies

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Prepend a prefix in every logs generated in the application #1290

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meetme2meat May 24, 2023

Replies: 2 comments

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stanislavkozlovski Sep 20, 2024

Uh oh!

charles-braga-unvoid Nov 1, 2024

meetme2meat
May 24, 2023

stanislavkozlovski
Sep 20, 2024

charles-braga-unvoid
Nov 1, 2024