slog

Hertz interfaces with slog and lumberjack.

Logger structure

var _ hlog.FullLogger = (*Logger)(nil)

type Logger struct {
    l   *slog.Logger
    cfg *config
}

NewLogger

Create and initialize a Logger through defaultConfig(). The required configuration can be passed into the function as a parameter. If no parameters are passed in, the initial configuration will be installed to create the Logger. For related configuration, please refer to option configuration below

Currently only slog.NewJSONHandler() in the slog library is supported, slog.NewTextHandler() is not supported

Function Signature:

func NewLogger(opts ...Option) *Logger

Sample code:

package main

import (
    "github.com/cloudwego/hertz/pkg/common/hlog"
    hertzslog "github.com/hertz-contrib/logger/slog"
    "os"
)

func main() {
    logger := hertzslog.NewLogger(hertzslog.WithOutput(os.Stdout))
    hlog.SetLogger(logger)
}

Logger

Logger is used to obtain *slog.Logger to meet complex operations

Function Signature:

func (l *Logger) Logger() *slog.Logger

Sample code:

package main

import (
    hertzslog "github.com/hertz-contrib/logger/slog"
    "os"
)

func main() {
    logger := hertzslog.NewLogger(hertzslog.WithOutput(os.Stdout))
    l := logger.Logger()
}

Option configuration

WithOutput

WithOutput is used to set the output location of the log

Function Signature:

func WithOutput(writer io.Writer) Option

Sample code:

package main

import (
    hertzslog "github.com/hertz-contrib/logger/slog"
    "os"
)

func main() {
    logger := hertzslog.NewLogger(hertzslog.WithOutput(os.Stdout))
}


WithLevel

WithLevel judges the incoming *slog.LevelVar. Only log levels higher than or equal to this will be recorded

It is worth noting that if WithLevel is set together with WithHandlerOptions, the log level of WithLevel will override the log level in WithHandlerOptions

Function Signature:

func WithLevel(lvl *slog.LevelVar) Option

Sample code:

package main

import (
    hertzslog "github.com/hertz-contrib/logger/slog"
)

func main() {
    //Empty LevelVar corresponds to LevelInfo
    logger := hertzslog.NewLogger(hertzslog.WithLevel(&slog.LevelVar{}))

    //Dynamically set the log level to Level Debug
    levelVar := slog.LevelVar{}
    levelVar.Set(slog.LevelDebug)
    logger := hertzslog.NewLogger(hertzslog.WithLevel(&slog.LevelVar{}))
}

WithHandlerOptions

WithHandlerOptions passes *slog.HandlerOptions into the configuration

Function Signature:

func WithHandlerOptions(opts *slog.HandlerOptions) Option

Sample code:

package main

import (
    hertzslog "github.com/hertz-contrib/logger/slog"
)

func main() {
    logger := hertzslog.NewLogger(hertzslog.WithHandlerOptions(&slog.HandlerOptions{
        AddSource:   false,
        Level:       slog.LevelInfo,
        ReplaceAttr: nil,
    }))
}

A complete slog example

package main

import (
	"context"
	"log"
	"os"
	"path"
	"time"

	"github.com/cloudwego/hertz/pkg/app"
	"github.com/cloudwego/hertz/pkg/app/server"
	"github.com/cloudwego/hertz/pkg/common/hlog"
	"github.com/cloudwego/hertz/pkg/protocol/consts"
	hertzslog "github.com/hertz-contrib/logger/slog"
	"gopkg.in/natefinch/lumberjack.v2"
)

func main() {
	h := server.Default()

	// Customizable output directory.
	var logFilePath string
	dir := "./hlog"
	logFilePath = dir + "/logs/"
	if err := os.MkdirAll(logFilePath, 0o777); err != nil {
		log.Println(err.Error())
		return
	}

	// 将文件名设置为日期
	logFileName := time.Now().Format("2006-01-02") + ".log"
	fileName := path.Join(logFilePath, logFileName)
	if _, err := os.Stat(fileName); err != nil {
		if _, err := os.Create(fileName); err != nil {
			log.Println(err.Error())
			return
		}
	}

	logger := hertzslog.NewLogger()
	// set filename to date
	lumberjackLogger := &lumberjack.Logger{
        Filename:   fileName,
        MaxSize:    20,   // A file can be up to 20M.
        MaxBackups: 5,    // Save up to 5 files at the same time
        MaxAge:     10,   // A file can be saved for up to 10 days.
        Compress:   true, // Compress with gzip.
	}

	logger.SetOutput(lumberjackLogger)
	logger.SetLevel(hlog.LevelDebug)

	hlog.SetLogger(logger)

	h.GET("/hello", func(ctx context.Context, c *app.RequestContext) {
		hlog.Info("Hello, hertz")
		c.String(consts.StatusOK, "Hello hertz!")
	})

	h.Spin()
}

For more details on how to adapt the interface of hlog, see hertz-contrib/logger/slog


Last modified October 16, 2024 : chore: update getting start idl (#1158) (3aa5e0f)