migrate to `log/slog` package

[thapabishwa]

I hope this message finds you well! I wanted to open a discussion regarding the possibility of migrating to the log/slog package within the go-retrablehttp project. This migration could offer several benefits to the project, improving its maintainability and enhancing logging functionalities.

Benefits of Using log/slog
Structured Logging: log/slog provides structured logging capabilities, enabling better organization and analysis of log data. This could significantly enhance the readability and comprehensibility of log entries within the project.

Contextual Logging: With the ability to add context to log messages, log/slog enables better traceability of events, aiding in debugging and troubleshooting.

Compatibility with Go 1.21: As Go evolves, staying updated with the latest features and functionalities is crucial. log/slog aligns with the direction Go is heading in version 1.21, ensuring compatibility and future-proofing the codebase.

Extensibility and Customization: The log/slog package offers various customization options, allowing the project to adapt logging behavior as per specific requirements.

[TLINDEN]

I second that, fmt.Println() doesn't help as I already use log/slog everywhere.

Thanks!

[whrss9527]

#231

[christiangda]

Hi everyone,

Here a Workarroung

... code omitted

var (
	logHandler        slog.Handler
	logHandlerOptions *slog.HandlerOptions
	logger            *slog.Logger
)

... code omitted

// My logger type to implement 'httpRetryableClient.Logger '
type retryableLogger struct {
	logger *slog.Logger
}

// Printf is the necessary method to implement 'httpRetryableClient.Logger '
func (r *retryableLogger) Printf(format string, args ...interface{}) {
	r.logger.Debug(fmt.Sprintf(format, args...))
}

... code omitted

func main() {
	logger = slog.New(logHandler)
	slog.SetDefault(logger)
... code omitted

	httpRetryableClient := retryablehttp.NewClient()
	httpRetryableClient.RetryMax = HTTPClientConfig.MaxRetries.Value
	httpRetryableClient.Backoff = retryablehttp.DefaultBackoff
	httpRetryableClient.CheckRetry = retryablehttp.DefaultRetryPolicy
	httpRetryableClient.Logger = &retryableLogger{logger: logger} // <----- assign the new slog logger

	httpClient := httpRetryableClient.StandardClient()

.... code omitted

}

[mitar]

This does not allow use of logger from context, so any extra structured data in the logger is not used.

[imjasonh]

Would there be any interest from the maintainers in a PR from the community to make this change?

[ErikKalkoken]

To clarify for anyone stumbling over this issue while looking for ways to integrate with slog.

retryablehttp already has built in support for slog. It supports the interface which is implemented by slog.Logger directly. Here is how you can setup a client with slog's default logger:

c := retryablehttp.NewClient()
c.Logger = slog.Default()

This still does not allow using context in the logger though.

[rhoban13]

Would such an implementation involve simply changing this to use slog.Default()? That seems it would enable clients to set the default globally. I'm not 100% clear what implications this might have in terms of backwards compatability