slogger

slogger is a Go package that wraps the slog package to add some convenient functionalities. It provides a flexible and easy-to-use interface for logging with additional options like different output modes, attribute customization, and more.

Features

• Output Modes: Supports both text and JSON output modes.
• Custom Attributes: Allows adding custom attributes to logs.
• Multiple Destinations: Supports logging to different io.Writer destinations.
• Log Level Configuration: Easy configuration of log levels.
• Sub-Loggers: Allows creation of sub-loggers for different components.
• DevNullLogger: A logger that writes to nowhere, useful for testing.

Installation

To install the package, run:

go get github.com/xorima/slogger

Usage

Creating a Logger

To create a new logger with default options:

import (
    "github.com/xorima/slogger"
)

loggerOpts := slogger.NewLoggerOpts("ServiceName", "ApplicationName")
logger := slogger.NewLogger(loggerOpts)

Customizing Logger

You can customize the logger by providing additional options:

loggerOpts := slogger.NewLoggerOpts(
    "ServiceName",
    "ApplicationName",
    slogger.WithDestination(os.Stderr),
    slogger.WithJsonOutput(),
    slogger.WithAttr(slog.String("environment", "production")),
)

logger := slogger.NewLogger(loggerOpts, slogger.WithLevel("debug"))

Sub-Loggers

Create sub-loggers for different components:

componentLogger := slogger.SubLogger(logger, "ComponentName")
componentLogger.Info("This is a log message from the component")

DevNullLogger

For testing purposes, you can use DevNullLogger:

devNullLogger := slogger.NewDevNullLogger()
devNullLogger.Info("This message will not be logged anywhere")

Error Attributes

To log errors with attributes:

err := errors.New("something went wrong")
logger.Error("An error occurred", slogger.ErrorAttr(err))

API Reference

NewLoggerOpts

Creates a new LoggerOpts instance.

func NewLoggerOpts(serviceName, applicationName string, opts ...func(o *LoggerOpts)) *LoggerOpts

WithDestination

Sets the log destination.

func WithDestination(destination io.Writer) func(o *LoggerOpts)

WithJsonOutput

Sets the output mode to JSON.

func WithJsonOutput() func(o *LoggerOpts)

WithAttr

Adds a custom attribute to the logger.

func WithAttr(attr slog.Attr) func(o *LoggerOpts)

NewLogger

Creates a new slog.Logger with the specified options.

func NewLogger(loggerOpts *LoggerOpts, handlerOpts ...func(o *slog.HandlerOptions)) *slog.Logger

WithSource

Includes the source of the log message.

func WithSource() func(o *slog.HandlerOptions)

WithLevel

Sets the log level.

func WithLevel(level string) func(o *slog.HandlerOptions)

WithReplaceAttr

Replaces an attribute with a custom function.

func WithReplaceAttr(fn func(groups []string, a slog.Attr) slog.Attr) func(o *slog.HandlerOptions)

SubLogger

Creates a sub-logger for a specific component.

func SubLogger(logger *slog.Logger, componentName string) *slog.Logger

DevNullLogger

A logger that writes to nowhere.

type DevNullLogger struct{}
func (d *DevNullLogger) Write(p []byte) (n int, err error)
func NewDevNullLogger() *slog.Logger

ErrorAttr

Creates an error attribute.

func ErrorAttr(err error) slog.Attr

License

This project is licensed under the Apache 2 License. See the LICENSE file for details.

Contributing

Contributions are welcome! Please open an issue or submit a pull request on GitHub.

Contact

For any questions or suggestions, feel free to reach out.