https://github.com/phsym/console-slog

A handler for slog that prints colorized logs, similar to zerolog's console writer output without sacrificing performances
https://github.com/phsym/console-slog

console go golang log logger logging slog

Last synced: 3 months ago
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A handler for slog that prints colorized logs, similar to zerolog's console writer output without sacrificing performances

• Host: GitHub
• URL: https://github.com/phsym/console-slog
• Owner: phsym
• License: mit
• Created: 2023-08-15T15:49:02.000Z (about 1 year ago)
• Default Branch: main
• Last Pushed: 2024-01-13T13:43:21.000Z (10 months ago)
• Last Synced: 2024-05-30T06:57:15.845Z (5 months ago)
• Topics: console, go, golang, log, logger, logging, slog
• Language: Go
• Homepage:
• Size: 82 KB
• Stars: 20
• Watchers: 1
• Forks: 3
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-slog - console-slog

README

        
# console-slog

[![Go Reference](https://pkg.go.dev/badge/github.com/phsym/console-slog.svg)](https://pkg.go.dev/github.com/phsym/console-slog) [![license](http://img.shields.io/badge/license-MIT-red.svg?style=flat)](https://raw.githubusercontent.com/phsym/console-slog/master/LICENSE) [![Build](https://github.com/phsym/console-slog/actions/workflows/go.yml/badge.svg?branch=main)](https://github.com/phsym/slog-console/actions/workflows/go.yml) [![codecov](https://codecov.io/gh/phsym/console-slog/graph/badge.svg?token=ZIJT9L79QP)](https://codecov.io/gh/phsym/console-slog) [![Go Report Card](https://goreportcard.com/badge/github.com/phsym/console-slog)](https://goreportcard.com/report/github.com/phsym/console-slog)

A handler for slog that prints colorized logs, similar to zerolog's console writer output without sacrificing performances.

## Installation

```bash

go get github.com/phsym/console-slog@latest

```

## Example

```go

package main

import (

	"errors"

	"log/slog"

	"os"

	"github.com/phsym/console-slog"

)

func main() {

	logger := slog.New(

		console.NewHandler(os.Stderr, &console.HandlerOptions{Level: slog.LevelDebug}),

	)

	slog.SetDefault(logger)

	slog.Info("Hello world!", "foo", "bar")

	slog.Debug("Debug message")

	slog.Warn("Warning message")

	slog.Error("Error message", "err", errors.New("the error"))

	logger = logger.With("foo", "bar").

		WithGroup("the-group").

		With("bar", "baz")

	logger.Info("group info", "attr", "value")

}

```

![output](./doc/img/output.png)

When setting `console.HandlerOptions.AddSource` to `true`:

```go

console.NewHandler(os.Stderr, &console.HandlerOptions{Level: slog.LevelDebug, AddSource: true})

```

![output-with-source](./doc/img/output-with-source.png)

## Performances

See [benchmark file](./bench_test.go) for details.

The handler itself performs quite well compared to std-lib's handlers. It does no allocation:

```

goos: linux

goarch: amd64

pkg: github.com/phsym/console-slog

cpu: Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz

BenchmarkHandlers/dummy-4               128931026            8.732 ns/op               0 B/op          0 allocs/op

BenchmarkHandlers/console-4               849837              1294 ns/op               0 B/op          0 allocs/op

BenchmarkHandlers/std-text-4              542583              2097 ns/op               4 B/op          2 allocs/op

BenchmarkHandlers/std-json-4              583784              1911 ns/op             120 B/op          3 allocs/op

```

However, the go 1.21.0 `slog.Logger` adds some overhead:

```

goos: linux

goarch: amd64

pkg: github.com/phsym/console-slog

cpu: Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz

BenchmarkLoggers/dummy-4                 1239873             893.2 ns/op             128 B/op          1 allocs/op

BenchmarkLoggers/console-4                483354              2338 ns/op             128 B/op          1 allocs/op

BenchmarkLoggers/std-text-4               368828              3141 ns/op             132 B/op          3 allocs/op

BenchmarkLoggers/std-json-4               393322              2909 ns/op             248 B/op          4 allocs/op

```