Accept a user provided logger

[maxdml]

This PR allows users to inject their existing logger to DBOS, for us to reuse.

Logging landscape

Go as four major loggers:

• log/slog https://pkg.go.dev/log/slog
• https://pkg.go.dev/go.uber.org/zap
• logrus (in maintenance mode but widely popular) https://github.com/sirupsen/logrus
• zerolog (up and coming) https://github.com/rs/zerolog

Why log/slog

It is design to be extensible with a custom Handler interface, and, fortunately, a long time golang contributor provided two libraries to convert a logrus or a zerolog logger into a slog instance:

• https://github.com/samber/slog-logrus
• https://github.com/samber/slog-zerolog

Zap has its own Handler compatibility layer.

These provide a simple way for a user to create a slog logger from their existing logger and retain their configuration.

example usage

func main() {
	//SLOG
	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
		Level: slog.LevelDebug,
	})).With("logger", "dbos-slog")
	err := dbos.Launch(dbos.WithLogger(logger))
	if err != nil {
		panic(err)
	}
	dbos.Shutdown()

	// ZAP
	zapLogger, err := zap.NewProduction()
	if err != nil {
		panic(err)
	}
	defer zapLogger.Sync()

	logger = slog.New(zapslog.NewHandler(zapLogger.Core(), zapslog.WithName("dbos-zap")))
	err = dbos.Launch(dbos.WithLogger(logger))
	if err != nil {
		panic(err)
	}
	dbos.Shutdown()

	// LOGRUS
	logrusLogger := logrus.New()
	logger = slog.New(sloglogrus.Option{
		Level:  slog.LevelDebug,
		Logger: logrusLogger,
	}.NewLogrusHandler())

	err = dbos.Launch(dbos.WithLogger(logger))
	if err != nil {
		panic(err)
	}
	dbos.Shutdown()

	// ZEROLOG
	zerologLogger := zerolog.New(zerolog.ConsoleWriter{
		Out: os.Stdout,
	}).With().Timestamp().Logger()

	logger = slog.New(slogzerolog.Option{
		Level:  slog.LevelDebug,
		Logger: &zerologLogger,
	}.NewZerologHandler())

	err = dbos.Launch(dbos.WithLogger(logger))
	if err != nil {
		panic(err)
	}
	dbos.Shutdown()
}

[maxdml]

test is flaky

[maxdml]

A simple gate to not panic