Aurora - Pretty Print Terminal Logging Library

Aurora is a lightweight Go library designed for beautiful, colorized, and structured terminal logging. It offers leveled logging with customizable symbols, automatic timestamps, and JSON pretty-printing capabilities, making it ideal for both development and production use.

Features

• 🌈 Colorized Output: Distinct colors for each log level
• ⏱ Timestamps: Automatic inclusion of timestamps
• 📛 Contextual Prefixes: Add module or component-specific prefixes
• 📦 JSON Pretty Printing: Built-in support for structured data
• 🔒 Thread-Safe: Safe concurrent logging
• 🍬 Sugar Functions: Convenient global logging methods
• 🎨 Customizable: Adjust symbols and colors to your liking

Installation

Install Aurora using:

go get github.com/olekukonko/aurora

Usage

Basic Logging

package main

import "github.com/olekukonko/aurora"

func main() {
	// Simple logging with sugar functions
	aurora.Info("System initialized")
	aurora.Warn("Disk space running low")
	aurora.Error("Failed to connect to database")

	// Formatted logging
	aurora.Debug("User %s logged in with %d attempts", "alice", 3)
}

Preview

Contextual Logging

func main() {
	// Create a logger with a prefix for context
	dbLogger := aurora.With("database")

	dbLogger.Info("Connection pool created")
	dbLogger.Warn("Slow query detected")
}

JSON Output

func main() {
    aurora.Br(2)
    aurora.Robot(aurora.InfoLevel)
    data := map[string]interface{}{
        "user": "bob",
        "age":  32,
        "tags": []string{"admin", "premium"},
    }
    
    aurora.Br(2)
    aurora.JSON("User Profile", data)
}

Preview

Advanced Usage

package main

import (
	"bytes"
	"github.com/olekukonko/aurora"
)

func main() {
	// Custom logger with a buffer
	var buf bytes.Buffer
	logger := aurora.New(&buf)
	logger.Robot(aurora.InfoLevel)

	// Full log with timestamp
	logger.Logf(aurora.NoticeLevel, "System check completed")

	// Inline log (no timestamp)
	logger.Inlinef(aurora.DebugLevel, "Processing item %d", 42)

	// Plain output (no symbol or timestamp)
	logger.Printf(aurora.InfoLevel, "Simple message")
}

Log Levels

Aurora supports the following log levels with default symbols and colors:

Level	Symbol	Color	Usage
Alert	✭	Blue	Important alerts
Info	✔	Green	Informational messages
Error	✘	Red	Error conditions
Notice	⚑	Yellow	Notable events
Debug	⧳	Cyan	Debug information
Warn	⚠	Magenta	Warning conditions
Critical	‼	White	Critical conditions

Configuration

Custom Output

The default logger writes to os.Stdout. Create custom loggers for different outputs:

// Write to a file
file, _ := os.Create("app.log")
fileLogger := aurora.New(file)

// Write to multiple outputs
multiWriter := io.MultiWriter(os.Stdout, file)
multiLogger := aurora.New(multiWriter)

Custom Symbols and Colors

Customize symbols and colors for specific log levels:

// Change symbol and color for Debug level
aurora.SetSymbol(aurora.DebugLevel, "[DEBUG]")
aurora.SetColor(aurora.DebugLevel, color.New(color.FgHiWhite))

Best Practices

• Contextual Logging: Use With() to create prefixed loggers for different components.
• Level Usage: Reserve Critical for severe issues and Debug for development verbosity.
• Structured Data: Use JSON() for logging complex data structures.
• Production: Combine with file or network writers for persistent logging.
• Testing: Capture output in tests using bytes.Buffer.

Example Output

Here’s what Aurora’s output might look like in your terminal:

    .=._,=.
   ' ([o]) `
     _)e(_
.'c ."|_|". n`.
'--'  /_\  `--'
     (   )
    __) (__


[✔] 2025-03-25 01:23:45 PM System initialized
[⚠] 2025-03-25 01:23:46 PM Disk space running low
[⧳] TestJSON: JSON ↴↴
{
    "user": "bob",
    "age": 32,
    "tags": ["admin", "premium"]
}

(Note: Colors not shown here; see actual terminal for full effect.)

For a real screenshot, consider adding one to your repo:

![Example terminal output](https://example.com/aurora-screenshot.png)

Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/xyz)
3. Commit your changes (git commit -m "Add xyz")
4. Push to the branch (git push origin feature/xyz)
5. Open a Pull Request

Dependencies

• fatih/color - Terminal color support
• mattes/go-asciibot - ASCII art generation
• nwidger/jsoncolor - JSON colorization

License

MIT License - see LICENSE for details.