1 简介

logrus的优点如下:

  • 完全兼容标准的log库
  • 内置了两种日志格式JSONFormater和TextFormatter
  • 允许使用者通过Hook的方式将日志分发到任意地方
  • 通过Filed机制进行结构化的日志记录

但是它用到了反射, 效率会相对低一点

提供的日志等级有:

  • logrus.Debug(“Useful debugging information.”)
  • logrus.Info(“Something noteworthy happened!”), 输出到stdout
  • logrus.Warn(“You should probably take a look at this.”)
  • logrus.Error(“Something failed but I’m not quitting.”), 输出到stderr, 还会继续执行
  • logrus.Panic(“I’m bailing.”) //log之后会panic(), 会退出所有协程
  • logrus.Fatal(“Bye.”) //log之后会调用os.Exit(1), 强制退出所有协程

    2 使用示例

    ```go package main

import ( log “github.com/sirupsen/logrus” )

func main() { log.Info(“hello”)

  1. log.WithFields(log.Fields{
  2.     "animal": "walrus",
  3. }).Info("a walrus appears")

}

  1. 运行结果如下:
  2. ```go
  3. INFO[0000] hello                                        
  4. INFO[0000] a walrus appears                              animal=walrus

3 设置log的参数

  1. package main
  3. import (
  4.     log "github.com/sirupsen/logrus"
  5.     "os"
  6. )
  8. func init() {
  9.     log.SetFormatter(&log.JSONFormatter{})
  10.     log.SetOutput(os.Stdout)
  11.     log.SetLevel(log.InfoLevel)
  12. }
  14. func main() {
  15.     log.Info("hello")
  16. }

运行结果如下:

  1. {"level":"info","msg":"hello","time":"2022-01-29T20:15:32+08:00"}

4 输出到文件

  1. package main
  3. import (
  4.     log "github.com/sirupsen/logrus"
  5.     "io"
  6.     "os"
  7. )
  9. func init() {
  10.     log.SetFormatter(&log.JSONFormatter{})
  11.     writer1 := os.Stdout
  12.     writer2, _ := os.OpenFile("log.txt", os.O_WRONLY|os.O_CREATE, 0755)
  13.     // 同时输出到 控制台, 文件
  14.     log.SetOutput(io.MultiWriter(writer1, writer2))
  15.     // 设置日志只记录Info及以上
  16.     log.SetLevel(log.InfoLevel)
  17. }
  19. func main() {
  20.     log.Info("hello")
  21. }

5 hook

hook的原理是，在logrus写入日志时拦截，修改logrus.Entry

  1. package main
  3. import (
  4.     log "github.com/sirupsen/logrus"
  5.     "io"
  6.     "os"
  7. )
  9. type MyFieldHook struct {
  10. }
  12. func (this MyFieldHook) Fire(entry *log.Entry) error {
  13.     entry.Data["tag"] = "ws"
  14.     return nil
  15. }
  17. func (this MyFieldHook) Levels() []log.Level {
  18.     return log.AllLevels
  19. }
  21. func init() {
  22.     log.SetFormatter(&log.JSONFormatter{})
  23.     writer1 := os.Stdout
  24.     writer2, _ := os.OpenFile("log.txt", os.O_WRONLY|os.O_CREATE, 0755)
  25.     log.SetOutput(io.MultiWriter(writer1, writer2))
  26.     log.SetLevel(log.InfoLevel)
  27.     hook := MyFieldHook{}
  28.     log.AddHook(hook)
  29.     log.SetReportCaller(true) // 输出文件名,行号,函数名
  30. }
  32. func main() {
  33.     log.Info("hello")
  34. }

运行结果如下:

{“file”:”/Users/ws/GolandProjects/awesomeProject/main.go:33”,”func”:”main.main”,”level”:”info”,”msg”:”hello”,”tag”:”ws”,”time”:”2022-01-29T20:35:54+08:00”}

6 日志文件切割

通过hook插件file-rotatelogs进行日志本地文件分割
日志轮转相关函数:

  • WithLinkName() 为最新的日志建立软连接
  • WithMaxAge() 设置文件清理前的最长保存时间
  • WithRotationTime() 设置日志分割的时间，隔多久分割一次
  • WithRotationCount() 设置文件清理前最多保存的个数

    注: WithMaxAge 和 WithRotationCount二者只能设置一个

  1. package main
  3. import (
  4.     "time"
  6.     rotatelogs "github.com/lestrrat-go/file-rotatelogs"
  7.     log "github.com/sirupsen/logrus"
  8. )
  10. func init() {
  11.     path := "./log/go.log"
  12.     writer, _ := rotatelogs.New(
  13.         path+".%Y%m%d%H%M",                          // 正在记录的日志文件
  14.         rotatelogs.WithLinkName(path),               // 正在记录的日志文件 对应的软链接(最好用绝对路径)
  15.         rotatelogs.WithMaxAge(180*time.Second),      // 设置文件清理前的最长保存时间
  16.         rotatelogs.WithRotationTime(60*time.Second), // 设置日志分割的时间，隔多久分割一次
  17.     )
  18.     log.SetOutput(writer)
  19. }
  21. func main() {
  22.     for {
  23.         log.Info("hello, world!")
  24.         time.Sleep(2 * time.Second)
  25.     }
  26. }

7 记录到ElasticSearch

  1. import (
  2.     log "github.com/sirupsen/logrus"
  3.     "github.com/olivere/elastic"
  4.     "gopkg.in/sohlich/elogrus"
  5. )
  7. func initLog() {
  8.     client, err := elastic.NewClient(elastic.SetURL("http://localhost:9200"))
  9.     if err != nil {
  10.         log.Panic(err)
  11.     }
  12.     hook, err := elogrus.NewElasticHook(client, "localhost", log.DebugLevel, "mylog")
  13.     if err != nil {
  14.         log.Panic(err)
  15.     }
  16.     log.AddHook(hook)
  17. }

8 记录到Mongo

  1. package main
  3. import (
  4.     log "github.com/sirupsen/logrus"
  5.     "github.com/weekface/mgorus"
  6. )
  8. func main() {
  9.     hook, err := mgorus.NewHooker("localhost:27017", "db", "collection")
  10.     if err != nil {
  11.         panic(err)
  12.     }
  13.     log.AddHook(hook)
  15.     log.WithFields(logrus.Fields{
  16.         "name": "zhangsan",
  17.         "age":  28,
  18.     }).Error("Hello world!")
  19. }

有时会报错: Failed to write to log, invalid argument
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