chore(tiup-publisher): add logs

[wuhuizuo]

Signed-off-by: wuhuizuo wuhuizuo@126.com

[ti-chi-bot]

I have already done a preliminary review for you, and I hope to help you do a better job.

Based on the pull request title and description, it seems that this pull request is adding logs to the tiup-publisher package. Specifically, the change adds log statements to each of the three steps of the handler function. The logs will be used to track the success or failure of these steps.

Overall, this is a good change. Adding logs is important for debugging and monitoring. However, there are a few potential problems that should be addressed:

1. The log level is dependent on an environment variable instead of being set in the code. This could lead to confusion if the environment variable is not set correctly. It would be better to set the default log level in the code itself.

2. The logs are using the default log format. It would be better to use a structured log format, such as JSON, so that the logs can be easily parsed and analyzed.

3. The logs are being sent to standard error. It would be better to send them to a dedicated log file or to a log aggregation service.

To address these issues, I suggest the following changes:

1. Set the default log level in the code itself, as follows:

	logLevel := zerolog.InfoLevel
	if os.Getenv("LOG_LEVEL") != "" {
		level, err := zerolog.ParseLevel(os.Getenv("LOG_LEVEL"))
		if err == nil {
			logLevel = level
		}
	}
	log.Logger = log.Level(logLevel)

2. Use a structured log format, such as JSON, as follows:

	log.Logger = zerolog.New(os.Stderr).With().Timestamp().Logger()

3. Send the logs to a dedicated log file or to a log aggregation service, as follows:

	// log to a file
	logFile, err := os.OpenFile("/var/log/tiup-publisher.log", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
	if err != nil {
		log.Fatal().Err(err).Msg("failed to open log file")
	}
	log.Logger = log.Logger.Output(logFile)

	// or log to a log aggregation service
	log.Logger = log.Logger.Hook(logrustash.New(os.Stderr, logrustash.DefaultFormatter(logrus.Fields{})))

[wuhuizuo]

/approve

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: wuhuizuo

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