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Loging

The logging is one of the most important practice that developers follow to have available information about any possible issue or application behaviour.

In Go there are a lot of available loggers with different APIs and implementation patterns. Because of that, Torpedo defines a simple interface that match with the official package log/slog and can be implemented by anyone or even any logger can be adapted to this interface via a wrapper struct.

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type ILogger interface {
    Debug(msg string, args ...any)
    Info(msg string, args ...any)
    Warn(msg string, args ...any)
    Error(msg string, args ...any)
}

Logger Provider

Torpedo creates a logger provider out-of-the-box injecting an instance of log.ILogger that can be bound fron other providers.

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package dependency

import (
    "github.com/darksubmarine/torpedo-lib-go/app"
    "github.com/darksubmarine/torpedo-lib-go/conf"
    "github.com/darksubmarine/torpedo-lib-go/log"
    "log/slog"
    "os"
)

type LoggerProvider struct {
    app.BaseProvider

    // logger instance to be provided
    logger log.ILogger `torpedo.di:"provide"`

    // private fields initialized by constructor
    cfg conf.Map
}

func NewLoggerProvider(config conf.Map) *LoggerProvider {
    return &LoggerProvider{cfg: config}
}

// Provide provides the logger instance.
func (p *LoggerProvider) Provide(c app.IContainer) error {
    // read log level from configuration. Info will be by default if not found.
    sLvl := conf.SlogLevel(p.cfg.FetchStringOrElse("info", "level"))

    // creating log instance as singleton.
    p.logger = slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: sLvl}))

    return nil
}