Go integrates logrus to realize log printing

Github:https://github.com/sirupsen/logrus

1 Preliminary use

package main

import (
   "context"
   "github.com/sirupsen/logrus"
)

func main() {
    
   method0()
}

func method0() {
    
   logger:= logrus.New()
   logger.Warning("This is a first log.")
   ctx := context.WithValue(context.Background(),"key","value")
   logger.Warning(ctx,"This is a second log.")
}

2 labeling WithFields

package main

import (
   "context"
   "github.com/sirupsen/logrus"
)

func main() {
    
   method1()
}

func method1() {
    
   log.WithFields(log.Fields{
    
      "fieldKey": "fieldValue",
   }).Warning("This is a first field log.")

   log.WithFields(log.Fields{
    
      "fieldKey": "fieldValue",
      "fieldKey2": "fieldValue2",
   }).Warning("This is a second field log.")
}

3 Configure common parameters

package main

import (
   "context"
   "github.com/sirupsen/logrus"
   log "github.com/sirupsen/logrus"
   "os"
)

func main() {
    
   method2()
}

func init() {
    
   //  Log as JSON Not the default ASCII Formatter .
   log.SetFormatter(&log.JSONFormatter{
    })

   //  Output to standard output , It could be anything io.Writer
   log.SetOutput(os.Stdout)

   //  Record only xx Level or above 
   log.SetLevel(log.TraceLevel)
}

func method2() {
    
   log.WithFields(log.Fields{
    
      "animal": "walrus",
      "size":   10,
   }).Info("A group of walrus emerges from the ocean")

   log.WithFields(log.Fields{
    
      "omg":    true,
      "number": 122,
   }).Warn("The group's number increased tremendously!")

   log.WithFields(log.Fields{
    
      "omg":    true,
      "number": 100,
   }).Fatal("The ice breaks!")
}

Formatter There are generally two kinds ：

• &log.JSONFormatter{}
• &log.TextFormatter{}

There are seven log levels ：

• log.Trace()
• log.Debug()
• log.Info()
• log.Warn()
• log.Error()
• log.Fatal()
• log.Panic()

4 Output log to file

package main

import (
	"context"
	"github.com/sirupsen/logrus"
	"os"
)

func main() {
    
	method4()
}

func method4() {
    
   var log = logrus.New()
   file ,err := os.OpenFile("logrus.log", os.O_CREATE|os.O_WRONLY, 0666)
   if err == nil{
    
      log.Out = file
   }else{
    
      log.Info("Failed to log to file")
   }

   log.WithFields(logrus.Fields{
    
      "filename": "123.txt",
   }).Info("This is a file log")
}

logrus.log The content of the document ：

time="2022-01-06T13:04:25+08:00" level=info msg="This is a file log" filename=123.txt\

5 utilize Hooks Output logs to other places

import (
  log "github.com/sirupsen/logrus"
  "gopkg.in/gemnasium/logrus-airbrake-hook.v2" // the package is named "airbrake"
  logrus_syslog "github.com/sirupsen/logrus/hooks/syslog"
  "log/syslog"
)

func init() {
    

  //  Use the airlock hook to report errors of severity or above an anomaly trace . You can create custom hooks , See the hook section .
  log.AddHook(airbrake.NewHook(123, "xyz", "production"))

  hook, err := logrus_syslog.NewSyslogHook("udp", "localhost:514", syslog.LOG_INFO, "")
  if err != nil {
    
    log.Error("Unable to connect to local syslog daemon")
  } else {
    
    log.AddHook(hook)
  }
}

Only need AddHook Yes, add the corresponding Hook That's all right.