首页 > 代码库 > golang之log rotate

golang之log rotate

操作系统: CentOS 6.9_x64

go语言版本: 1.8.3

问题描述

golang的log模块提供的有写日志功能,示例代码如下:

/*golang log exampleE-Mail : Mike_Zhang@live.com*/package mainimport (    "log"    "os")func main() {    logFile,err := os.Create("test1.log")    defer logFile.Close()    if err != nil {        log.Fatalln("open file error!")    }    logger := log.New(logFile,"[Debug]",log.Ldate | log.Ltime | log.Lshortfile)    logger.Println("test debug message")    logger.SetPrefix("[Info]")    logger.Println("test info message")}

运行效果:

[root@local t2]# go build logTest1.go[root@local t2]# ./logTest1[root@local t2]# cat test1.log[Debug]2017/06/13 23:18:36 logTest1.go:19: test debug message[Info]2017/06/13 23:18:36 logTest1.go:21: test info message[root@local t2]#

go语言的log模块没有提供log rotate接口,但实际开发中我们需要该功能:

我们不希望单个日志过大,否则文本编辑器无法打开,查看比较困难;

更不希望占用太大的存储空间,可以指定最多存多少个日志文件。

解决方案

借助带缓冲的channel来实现。

示例代码如下:

/*    golang log rotate example    E-Mail : Mike_Zhang@live.com*/package mainimport (    "fmt"    "log"    "os"    "time")const (    BACKUP_COUNT = 5    MAX_FILE_BYTES = 2 * 1024)func doRotate(fPrefix string) {    for j := BACKUP_COUNT; j >= 1; j-- {        curFileName := fmt.Sprintf("%s_%d.log",fPrefix,j)        k := j-1        preFileName := fmt.Sprintf("%s_%d.log",fPrefix,k)        if k == 0 {            preFileName = fmt.Sprintf("%s.log", fPrefix)        }        _,err := os.Stat(curFileName)        if err == nil {            os.Remove(curFileName)            fmt.Println("remove : ", curFileName)        }        _,err = os.Stat(preFileName)        if err  == nil {            fmt.Println("rename : ", preFileName, " => ", curFileName)            err = os.Rename(preFileName, curFileName)            if err != nil {                fmt.Println(err)            }        }    }}func NewLogger(fPrefix string) (*log.Logger, *os.File) {    var logger *log.Logger    fileName := fmt.Sprintf("%s.log", fPrefix)    fmt.Println("fileName :", fileName)    logFile, err := os.OpenFile(fileName, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)    if err != nil {        fmt.Println("open file error!")    } else {        logger = log.New(logFile, "[Debug]", log.Ldate|log.Ltime|log.Lshortfile)    }    return logger, logFile}func logWorker(msgQueue <-chan string) {    fPrefix := "msg"    logger, logFile := NewLogger(fPrefix)    for msg := range msgQueue {        logger.Println(msg)        fi, err2 := logFile.Stat()        if err2 == nil {            if fi.Size() > MAX_FILE_BYTES {                logFile.Close()                doRotate(fPrefix)                logger,logFile = NewLogger(fPrefix)            }        }    }    logFile.Close()}func main() {    msgQueue := make(chan string, 1000)    go logWorker(msgQueue)    for j := 1; j <= 1000; j++ {        msgQueue <- fmt.Sprintf("msg_%d", j)        time.Sleep(1 * time.Second)    }    close(msgQueue)    return}

运行效果如下:

[root@local t2]# ./logRotateTest1fileName : msg.logrename :  msg.log  =>  msg_1.logfileName : msg.logrename :  msg_1.log  =>  msg_2.logrename :  msg.log  =>  msg_1.logfileName : msg.logrename :  msg_2.log  =>  msg_3.logrename :  msg_1.log  =>  msg_2.logrename :  msg.log  =>  msg_1.logfileName : msg.log^C

讨论

这里只是个简单的示例代码,实现了log rotate,更多功能需自行开发。

好,就这些了,希望对你有帮助。

本文github地址:

https://github.com/mike-zhang/mikeBlogEssays/blob/master/2017/20170614_golang之logRotate.rst

欢迎补充 

golang之log rotate