log/

Log

Logging utilities for Go applications.

Overview

The log package provides high-level logging abstractions with support for multiple logging backends. It includes wrappers for both structured logging (slog) and Kubernetes-style logging (klog).

Subpackages

slog

Structured logging with asynchronous processing, multiple outputs, and daily rotation.

📖 Documentation

Features:

• Asynchronous log processing with queue-based buffering
• Multiple output destinations (stdout, stderr, file)
• Daily log file rotation
• Configurable log levels (Trace, Debug, Info, Warn, Error, Fatal)
• Caller information tracking

Quick Example:

import "github.com/common-library/go/log/slog"

slog.SetOutputToFile("/var/log/app.log", 7, 100, 100*1024*1024)
slog.Info("Application started")
defer slog.Flush()

klog

Kubernetes-style logging wrapper with structured and formatted logging support.

📖 Documentation

Features:

• Kubernetes ecosystem compatibility
• Structured logging (InfoS, ErrorS)
• Formatted logging (Infof, Errorf)
• Caller tracking for debugging
• Fatal logging with application exit

Quick Example:

import "github.com/common-library/go/log/klog"

klog.Info("Server started")
klog.InfoS("Request processed", "method", "GET", "path", "/api/users")
defer klog.Flush()

Choosing a Logger

Installation

go get -u github.com/common-library/go/log/slog
go get -u github.com/common-library/go/log/klog

Best Practices

1. Always Flush - Call Flush() before application exit
2. Set Appropriate Levels - Use Debug/Trace for development, Info+ for production
3. Structured Data - Prefer structured logging for machine parsing
4. Caller Info - Enable in development, consider disabling in production for performance
5. File Rotation - Configure appropriate retention for disk space management

Further Reading

• slog Package Documentation
• klog Package Documentation