README.md

nlog

A simple, pretty-printed JSON logging package for Go that provides structured logging with automatic trace information for errors.

Features

• Structured JSON logging with pretty-printed output
• Three log levels: Info, Warn, and Error
• Automatic trace capture for errors (file, function, and line number)
• Context support for adding additional fields to log entries
• Color-coded output via go-prettyjson

Installation

go get github.com/xDeFc0nx/nlog

Usage

Basic Logging

package main

import "github.com/xDeFc0nx/nlog"

func main() {
    // Info logging
    nlog.Info("Application started", nil)

    // Info with context
    nlog.Info("User logged in", map[string]any{
        "user_id": 12345,
        "ip": "192.168.1.1",
    })

    // Warning
    nlog.Warn("API rate limit approaching", map[string]any{
        "remaining": 10,
        "limit": 100,
    })
}

Error Logging with Automatic Trace

func processData() error {
    err := someOperation()
    if err != nil {
        nlog.Error(err, map[string]any{
            "operation": "data_processing",
            "input_size": 1024,
        })
        return err
    }
    return nil
}

Output:

{
  "level": "ERROR",
  "msg": "connection timeout",
  "trace": "main.go:42  main.processData",
  "operation": "data_processing",
  "input_size": 1024
}

API Reference

Info(msg string, context map[string]any)

Logs an informational message with optional context fields.

• msg: The log message
• context: Additional key-value pairs to include in the log entry (can be nil)

Warn(msg string, context map[string]any)

Logs a warning message with optional context fields.

• msg: The log message
• context: Additional key-value pairs to include in the log entry (can be nil)

Error(err error, context map[string]any)

Logs an error with automatic trace information (file, function, line number) and optional context fields.

• err: The error to log (if nil, nothing is logged)
• context: Additional key-value pairs to include in the log entry (can be nil)

Dependencies

• github.com/hokaccha/go-prettyjson - For pretty-printed, color-coded JSON output

License

MIT