logrus email hook

logurs_hook.go

package common

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net"
	"net/mail"
	"net/smtp"
	"strconv"
	"time"

	"github.com/sirupsen/logrus"
)

//Logger 可以使用这个logger 也可直接使用logrus
var Logger = logrus.New()

//SetLogger 初始化logrus 同时把logrus的logger var 引用到这个common.Logger
func SetLogger(cfg Config, verbose bool) error {
	//logFileName := fmt.Sprintf("app.gin.%s.%s.log", cfg.Web.Name, time.Now().Format("20060102T15"))
	//
	//f, err := os.Create(logFileName)
	//if err != nil {
	//	return err
	//}

	logLvl, err := logrus.ParseLevel(cfg.LogLevel)
	if err != nil {
		return err
	}
	logrus.SetLevel(logLvl)
	logrus.SetReportCaller(true)
	//logrus.SetFormatter(&logrus.JSONFormatter{})
	//使用console默认输出
	if (cfg.Env == "dev" || cfg.Env == "test") && cfg.Mail.Host != "" {
		hook, err := newMailAuthHook(cfg.Web.Name, cfg.Mail.Host, cfg.Mail.Port, cfg.Mail.Limit, cfg.Mail.User, cfg.Mail.User, cfg.Mail.Password, cfg.Mail.Receivers)
		if err != nil {
			return err
		}
		logrus.AddHook(hook)
	}
	//logrus.SetOutput(f)
	//logrus.SetReportCaller(verbose)
	Logger = logrus.StandardLogger()
	return nil
}

const (
	format = "20060102 15:04:05"
)

// mailHook to sends logs by email with authentication.
type mailHook struct {
	appName       string
	emailHost     string
	emailPort     int
	emailFrom     *mail.Address
	emailTos      []string
	emailUserName string
	emailPassword string
	buff          *bytes.Buffer
	count         int
	limit         int
}

// newMailAuthHook creates a hook to be added to an instance of logger.
func newMailAuthHook(app string, host string, port, limit int, from string, username string, password string, to []string) (*mailHook, error) {
	// Check if server listens on that port.
	conn, err := net.DialTimeout("tcp", host+":"+strconv.Itoa(port), 3*time.Second)
	if err != nil {
		return nil, err
	}
	defer conn.Close()

	// Validate sender and recipient
	sender, err := mail.ParseAddress(from)
	if err != nil {
		return nil, err
	}
	for _, v := range to {
		_, err := mail.ParseAddress(v)
		if err != nil {
			return nil, fmt.Errorf("%s 不是有效的邮箱:%s", v, err)
		}
	}

	return &mailHook{
		appName:       app,
		emailHost:     host,
		emailPort:     port,
		emailFrom:     sender,
		emailTos:      to,
		emailUserName: username,
		emailPassword: password,
		buff:          bytes.NewBufferString(""),
		limit:         limit,
		count:         0,
	}, nil
}

// Fire is called when a log event is fired.
func (hook *mailHook) Fire(entry *logrus.Entry) error {
	if hook.count < hook.limit {
		hook.storeError(entry)
		return nil
	}
	return hook.sendEmail()
}

// Levels returns the available logging levels.
func (hook *mailHook) Levels() []logrus.Level {
	return []logrus.Level{
		logrus.PanicLevel,
		logrus.FatalLevel,
		logrus.ErrorLevel,
	}
}
func (hook *mailHook) storeError(entry *logrus.Entry) {
	body := entry.Time.Format(format) + " - " + entry.Message
	hook.buff.WriteString(body)
	fields, _ := json.MarshalIndent(entry.Data, "", "\t")
	hook.buff.Write(fields)
	hook.buff.Write([]byte("\r\n"))
	callers, _ := json.MarshalIndent(entry.Caller, "", "\t")
	hook.buff.Write(callers)
	hook.buff.Write([]byte("\r\n"))
	hook.count++
}

func (hook *mailHook) sendEmail() error {
	auth := smtp.PlainAuth("", hook.emailUserName, hook.emailPassword, hook.emailHost)

	subject := hook.appName + " - " + time.Now().Format(format)
	body, _ := ioutil.ReadAll(hook.buff)
	hook.buff.Reset()
	contents := fmt.Sprintf("Subject: %s\r\n\r\n%s", subject, body)
	hook.count = 0

	// Connect to the server, authenticate, set the sender and recipient,
	// and send the email all in one step.
	err := smtp.SendMail(
		hook.emailHost+":"+strconv.Itoa(hook.emailPort),
		auth,
		hook.emailFrom.Address,
		hook.emailTos,
		[]byte(contents),
	)
	if err != nil {
		return err
	}
	return nil
}