logng

logng is a Go (Golang) package that provides structured and leveled logging.

Features

Leveled logging: FATAL, ERROR, WARNING, INFO, DEBUG
Verbose support
Text and JSON output
Customizable output
Function and file logging
Stack trace logging
Field support
Performance optimized

Installation

You can install logng using the go get command:

go get github.com/goinsane/logng/v2

Examples

Basic example

package main

import (
	"errors"

	"github.com/goinsane/logng/v2"
)

func main() {
	// log by severity and verbosity.
	// default Logger's severity is SeverityInfo.
	// default Logger's verbose is 0.
	logng.Debug("this is debug log. it won't be shown.")
	logng.Info("this is info log.")
	logng.Warning("this is warning log.")
	logng.V(1).Error("this is error log, verbosity 1. it won't be shown.")

	// set stack trace severity
	logng.SetStackTraceSeverity(logng.SeverityWarning)

	// logs with stack trace, because the log severity is warning
	logng.Warningf("a warning: %w", errors.New("unknown"))

	// log with fields
	logger := logng.WithFieldKeyVals("user_name", "john", "ip", "1.2.3.4")
	logger.Infof("connected user:\n%s", "John Smith")

	// logs with fields and stack trace
	logger.Error("an error")
}

2023/11/21 16:18:37 INFO - this is info log.
2023/11/21 16:18:37 WARNING - this is warning log.
2023/11/21 16:18:37 WARNING - a warning: unknown
    
	main.main(0x104d6f7b0)
		main.go:22 +0x150
	runtime.main(0x104d0a2e0)
		proc.go:250 +0x247
	runtime.goexit(0x104d35390)
		asm_arm64.s:1172 +0x3
    
2023/11/21 16:18:37 INFO - connected user:
                           John Smith
    
	+ "user_name"="john" "ip"="1.2.3.4"
    
2023/11/21 16:18:37 ERROR - an error
    
	+ "user_name"="john" "ip"="1.2.3.4"
    
	main.main(0x104d6f7b0)
		main.go:29 +0x248
	runtime.main(0x104d0a2e0)
		proc.go:250 +0x247
	runtime.goexit(0x104d35390)
		asm_arm64.s:1172 +0x3

More examples

To run any example, please use the command like the following:

cd examples/example1/
go run *.go

Tests

To run all tests, please use the following command:

go test -v

To run all examples, please use the following command:

go test -v -run=^Example

To run all benchmarks, please use the following command:

go test -v -run=^Benchmark -bench=.

Contributing

We welcome contributions from the community to improve and expand project capabilities. If you find a bug, have a feature request, or want to contribute code, please follow our guidelines for contributing (CONTRIBUTING.md) and submit a pull request.

License

This project is licensed under the BSD 3-Clause License.