logfx

ajan/logfx

Overview

logfx package is a configurable logging solution leverages the log/slog of the standard library for structured logging. It includes pretty-printing options. The package supports OpenTelemetry-compatible severity levels and provides extensive test coverage to ensure reliability and correctness.

The documentation below provides an overview of the package, its types, functions, and usage examples. For more detailed information, refer to the source code and tests.

Configuration

Configuration struct for the logger:

type Config struct {
	Level      string `conf:"level"      default:"INFO"`
	PrettyMode bool   `conf:"pretty"     default:"true"`
	AddSource  bool   `conf:"add_source" default:"false"`
}

The supported log levels (in ascending order of severity) are:

• TRACE - Detailed information for debugging
• DEBUG - Debugging information
• INFO - General operational information
• WARN - Warning messages for potentially harmful situations
• ERROR - Error messages for serious problems
• FATAL - Critical errors causing program termination
• PANIC - Critical errors causing panic

These levels are compatible with OpenTelemetry Severity levels, allowing seamless integration with observability platforms.

API

NewLogger function

Creates a new logfx.Logger object based on the provided configuration.

// func NewLogger(w io.Writer, config *Config) *logfx.Logger

logger := logfx.NewLogger(os.Stdout, config)

NewLoggerAsDefault function

Creates a new logfx.Logger object based on the provided configuration and makes it default slog instance.

// func NewLoggerAsDefault(w io.Writer, config *Config) *logfx.Logger

logger := logfx.NewLoggerAsDefault(os.Stdout, config)

Colored outputs

Logs ANSI-colored strings.

// func Colored(color Color, message string) string

// available colors:
//	ColorReset        ColorDimGray
//	ColorRed          ColorLightRed
//	ColorGreen        ColorLightGreen
//	ColorYellow       ColorLightYellow
//	ColorBlue         ColorLightBlue
//	ColorMagenta      ColorLightMagenta
//	ColorCyan         ColorLightCyan
//	ColorGray         ColorLightGray

logger.Fatal(
  logfx.Colored(logfx.ColorLightYellow, "Hello, World!"),
  slog.String("first_name", "Eser"),
  slog.String("last_name", "Ozvataf"),
)