https://github.com/matusollah/slogcolor

Color handler for log/slog
https://github.com/matusollah/slogcolor

ansi-colors color go go-slog golang golang-slog golang-slog-handler log logger logging slog structured-logging zerolog

Last synced: about 1 month ago
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Color handler for log/slog

• Host: GitHub
• URL: https://github.com/matusollah/slogcolor
• Owner: MatusOllah
• License: mit
• Created: 2024-02-17T19:24:14.000Z (11 months ago)
• Default Branch: main
• Last Pushed: 2024-09-11T12:33:18.000Z (4 months ago)
• Last Synced: 2024-09-11T17:08:29.935Z (4 months ago)
• Topics: ansi-colors, color, go, go-slog, golang, golang-slog, golang-slog-handler, log, logger, logging, slog, structured-logging, zerolog
• Language: Go
• Homepage: https://pkg.go.dev/github.com/MatusOllah/slogcolor
• Size: 65.4 KB
• Stars: 9
• Watchers: 1
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE

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README

        
# 🌈 slogcolor

[![Go Reference](https://pkg.go.dev/badge/github.com/MatusOllah/slogcolor.svg)](https://pkg.go.dev/github.com/MatusOllah/slogcolor) [![Go Report Card](https://goreportcard.com/badge/github.com/MatusOllah/slogcolor)](https://goreportcard.com/report/github.com/MatusOllah/slogcolor) [![GitHub license](https://img.shields.io/github/license/MatusOllah/slogcolor)](https://github.com/MatusOllah/slogcolor/blob/main/LICENSE)

![screenshot](https://github.com/MatusOllah/slogcolor/blob/main/screenshot.png)

**slogcolor** is a little, customizable color handler for `log/slog`. It enhances log readability by color-coding log levels and supports flexible formatting options.

Its output is inspired by XMRig and zerolog.

## Installation

Run:

```sh

go get -u github.com/MatusOllah/slogcolor

```

## Basic Usage

```go

package main

import (

    "os"

    "time"

    "errors"

    "log/slog"

    "github.com/MatusOllah/slogcolor"

)

func main() {

    // Configure slog to use slogcolor by default for colored output

    slog.SetDefault(slog.New(slogcolor.NewHandler(os.Stderr, slogcolor.DefaultOptions)))

    slog.Info("Initializing")

    slog.Debug("Init done", "duration", 500*time.Millisecond)

    slog.Warn("Slow request!", "method", "GET", "path", "/api/users", "duration", 750*time.Millisecond)

    slog.Error("DB connection lost!", "err", errors.New("connection reset"), "db", "horalky")

}

```

### Customized output format

The output format can also be customized using the [`Options`](https://pkg.go.dev/github.com/MatusOllah/slogcolor#Options) like this:

```go

opts := &slogcolor.Options{

    Level:         slog.LevelDebug,

    TimeFormat:    time.RFC3339,

    SrcFileMode:   slog.Nop,

}

slog.SetDefault(slog.New(slogcolor.NewHandler(os.Stderr, opts)))

```

or like this:

```go

opts := slogcolor.DefaultOptions

opts.Level = slog.LevelDebug

opts.TimeFormat = time.RFC3339

opts.SrcFileMode = slog.Nop

slog.SetDefault(slog.New(slogcolor.NewHandler(os.Stderr, opts)))

```

### Prefixes

Prefixes can be useful for adding context to log messages, such as identifying different subsystems or components (e.g., `DB`, `SceneController`, `Network`) that generated the log.

Messages can be prefixed with [`Prefix`](https://pkg.go.dev/github.com/MatusOllah/slogcolor#Prefix) like this:

```go

slog.Info(slogcolor.Prefix("MyPrefix", "kajšmentke"))

slog.Info(slogcolor.Prefix("SceneController", "switching scene"), "scene", "MainMenuScene")

// or

slog.Info(slogcolor.Prefix("MyPrefix")+"kajšmentke")

slog.Info(slogcolor.Prefix("SceneController")+"switching scene", "scene", "MainMenuScene")

```

It can also be used as an alias for ease of use, especially when you frequently use prefixes, like this:

```go

var P = slogcolor.Prefix

slog.Info(P("MyPrefix", "kajšmentke"))

// or

slog.Info(P("MyPrefix")+"kajšmentke")

```

### Disable colors

Colors are enabled by default but can be disabled using `Options.NoColor`. Particularly useful for automatically enabling colors based on the terminal capabilities using e.g. the [`go-isatty`](https://github.com/mattn/go-isatty) package.

```go

w := os.Stderr

opts := slogcolor.DefaultOptions

opts.NoColor = !isatty.IsTerminal(w.Fd())

slog.SetDefault(slog.New(slogcolor.NewHandler(w, opts)))

```

## License

Licensed under the **MIT License** (see [LICENSE](https://github.com/MatusOllah/slogcolor/blob/main/LICENSE))