简单的golang Logrus使用教程

package main
import (
  log "github.com/sirupsen/logrus"
)
func main() {
  log.WithFields(log.Fields{
    "animal": "walrus",
  }).Info("A walrus appears")
}

package main
import (
  "os"
  log "github.com/sirupsen/logrus"
)
func init() {
  // Log 为JSON而不是默认的ASCII格式。
  log.SetFormatter(&log.JSONFormatter{})
  // 输出到标准输出，而不是默认的标准错误
  //可以是任何io.Writer，请参阅下面的文件例如日志。
  log.SetOutput(os.Stdout)
  // 仅记录严重警告以上。
  log.SetLevel(log.WarnLevel)
}
func main() {
  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!")
  // 一种常见的模式是通过重用
  //从WithFields返回的logrus.Entry 来重用日志记录语句之间的字段
  contextLogger := log.WithFields(log.Fields{
    "common": "this is a common field",
    "other": "I also should be logged always",
  })
  contextLogger.Info("I'll be logged with common and other field")
  contextLogger.Info("Me too")
}

package main
import (
  "os"
  "github.com/sirupsen/logrus"
)
// 创建记录器的一个新实例。您可以有任意多个实例
var log = logrus.New()
func main() {
  // 用于设置属性的API与程序包级别
  // 导出的记录器有些不同。见Godoc。
  log.Out = os.Stdout
  // 您可以将其设置为任何`io.Writer`
  // file, err := os.OpenFile("logrus.log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
  // if err == nil {
  //  log.Out = file
  // } else {
  //  log.Info("Failed to log to file, using default stderr")
  // }
  log.WithFields(logrus.Fields{
    "animal": "walrus",
    "size":   10,
  }).Info("A group of walrus emerges from the ocean")
}

log.WithFields(log.Fields{
  "event": event,
  "topic": topic,
  "key": key,
}).Fatal("Failed to send event")

requestLogger := log.WithFields(log.Fields{"request_id": request_id, "user_ip": user_ip})
requestLogger.Info("something happened on that request") # will log request_id and user_ip
requestLogger.Warn("something not great happened")

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 Airbrake hook to report errors that have Error severity or above to
  // an exception tracker. You can create custom hooks, see the Hooks 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)
  }
}

log.Trace("Something very low level.")
log.Debug("Useful debugging information.")
log.Info("Something noteworthy happened!")
log.Warn("You should probably take a look at this.")
log.Error("Something failed but I'm not quitting.")
// Calls os.Exit(1) after logging
log.Fatal("Bye.")
// Calls panic() after logging
log.Panic("I'm bailing.")

// Will log anything that is info or above (warn, error, fatal, panic). Default.
log.SetLevel(log.InfoLevel)

import (
  log "github.com/sirupsen/logrus"
)
init() {
  // do something here to set environment depending on an environment variable
  // or command-line flag
  if Environment == "production" {
    log.SetFormatter(&log.JSONFormatter{})
  } else {
    // The TextFormatter is default, you don't actually have to do this.
    log.SetFormatter(&log.TextFormatter{})
  }
}

type MyJSONFormatter struct {
}
log.SetFormatter(new(MyJSONFormatter))
func (f *MyJSONFormatter) Format(entry *Entry) ([]byte, error) {
  // Note this doesn't include Time, Level and Message which are available on
  // the Entry. Consult `godoc` on information about those fields or read the
  // source of the official loggers.
  serialized, err := json.Marshal(entry.Data)
    if err != nil {
      return nil, fmt.Errorf("Failed to marshal fields to JSON, %v", err)
    }
  return append(serialized, '\n'), nil
}

w := logger.Writer()
defer w.Close()
srv := http.Server{
    // create a stdlib log.Logger that writes to
    // logrus.Logger.
    ErrorLog: log.New(w, "", 0),
}

logger := logrus.New()
logger.Formatter = &logrus.JSONFormatter{}
// Use logrus for standard log output
// Note that `log` here references stdlib's log
// Not logrus imported under the name `log`.
log.SetOutput(logger.Writer())