logrus hook输出日志到本地磁盘的操作

logrus是go的一个日志框架，它最让人激动的应该是hook机制，可以在初始化时为logrus添加hook，logrus可以实现各种扩展功能，可以将日志输出到elasticsearch和activemq等中间件去，甚至可以输出到你的email和叮叮中去，不要问为为什么可以发现可以输入到叮叮中去，都是泪，手动笑哭！

言归正传，这里就简单的通过hook机制将文件输出到本地磁盘。

首先

go get github.com/sirupsen/logrus

然后

logrus和go lib里面一样有6个等级，可以直接调用

logrus.Debug("Useful debugging information.")
logrus.Info("Something noteworthy happened!")
logrus.Warn("You should probably take a look at this.")
logrus.Error("Something failed but I'm not quitting.")
logrus.Fatal("Bye.")  //log之后会调用os.Exit(1)
logrus.Panic("I'm bailing.")  //log之后会panic()

项目例子结构

main.go

package main

import (
"fmt"
"github.com/sirupsen/logrus"
"logT/logS"
)
func main() {
 //创建一个hook，将日志存储路径输入进去
hook := logS.NewHook("d:/log/golog.log")
//加载hook之前打印日志
logrus.WithField("file", "d:/log/golog.log").Info("New logrus hook err.")
logrus.AddHook(hook)
//加载hook之后打印日志
logrus.WithFields(logrus.Fields{
"animal": "walrus",
}).Info("A walrus appears")
}

hook.go

不要看下面三个go文件代码很长，其实大多数都是固定代码，也就NewHook函数自己扩展定义就好

package logS

import (
"fmt"
"github.com/sirupsen/logrus"
"os"
"strings"
)

// Hook 写文件的Logrus Hook
type Hook struct {
W LoggerInterface
}

func NewHook(file string) (f *Hook) {
w := NewFileWriter()
config := fmt.Sprintf(`{"filename":"％s","maxdays":7}`, file)
err := w.Init(config)
if err != nil {
return nil
}

return &Hook{w}
}

// Fire 实现Hook的Fire接口
func (hook *Hook) Fire(entry *logrus.Entry) (err error) {
message, err := getMessage(entry)
if err != nil {
fmt.Fprintf(os.Stderr, "Unable to read entry, ％v", err)
return err
}
switch entry.Level {
case logrus.PanicLevel:
fallthrough
case logrus.FatalLevel:
fallthrough
case logrus.ErrorLevel:
return hook.W.WriteMsg(fmt.Sprintf("[ERROR] ％s", message), LevelError)
case logrus.WarnLevel:
return hook.W.WriteMsg(fmt.Sprintf("[WARN] ％s", message), LevelWarn)
case logrus.InfoLevel:
return hook.W.WriteMsg(fmt.Sprintf("[INFO] ％s", message), LevelInfo)
case logrus.DebugLevel:
return hook.W.WriteMsg(fmt.Sprintf("[DEBUG] ％s", message), LevelDebug)
default:
return nil
}
}

// Levels 实现Hook的Levels接口
func (hook *Hook) Levels() []logrus.Level {
return []logrus.Level{
logrus.PanicLevel,
logrus.FatalLevel,
logrus.ErrorLevel,
logrus.WarnLevel,
logrus.InfoLevel,
logrus.DebugLevel,
}
}

func getMessage(entry *logrus.Entry) (message string, err error) {
message = message + fmt.Sprintf("％s ", entry.Message)
file, lineNumber := GetCallerIgnoringLogMulti(2)
if file != "" {
sep := fmt.Sprintf("％s/src/", os.Getenv("GOPATH"))
fileName := strings.Split(file, sep)
if len(fileName) >= 2 {
 file = fileName[1]
}
}
message = fmt.Sprintf("％s:％d ", file, lineNumber) + message

for k, v := range entry.Data {
message = message + fmt.Sprintf("％v:％v ", k, v)
}
return
}

caller.go

package logS

import (
"runtime"
"strings"
)

func GetCaller(callDepth int, suffixesToIgnore ...string) (file string, line int) {
// bump by 1 to ignore the getCaller (this) stackframe
callDepth++
outer:
for {
var ok bool
_, file, line, ok = runtime.Caller(callDepth)
if !ok {
 file = "???"
 line = 0
 break
}

for _, s := range suffixesToIgnore {
 if strings.HasSuffix(file, s) {
 callDepth++
 continue outer
 }
}
break
}
return
}

// GetCallerIgnoringLogMulti TODO
func GetCallerIgnoringLogMulti(callDepth int) (string, int) {
// the +1 is to ignore this (getCallerIgnoringLogMulti) frame
return GetCaller(callDepth+1, "logrus/hooks.go", "logrus/entry.go", "logrus/logger.go", "logrus/exported.go", "asm_amd64.s")
}

file.go

package logS

import (
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"log"
"os"
"path/filepath"
"strings"
"sync"
"time"
)

// RFC5424 log message levels.
const (
LevelError = iota
LevelWarn
LevelInfo
LevelDebug
)

// LoggerInterface Logger接口
type LoggerInterface interface {
Init(config string) error
WriteMsg(msg string, level int) error
Destroy()
Flush()
}

// LogWriter implements LoggerInterface.
// It writes messages by lines limit, file size limit, or time frequency.
type LogWriter struct {
*log.Logger
mw *MuxWriter
// The opened file
Filename string `json:"filename"`

Maxlines     int `json:"maxlines"`
maxlinesCurlines int

// Rotate at size
Maxsize    int `json:"maxsize"`
maxsizeCursize int

// Rotate daily
Daily     bool `json:"daily"`
Maxdays    int64 `json:"maxdays"`
dailyOpendate int

Rotate bool `json:"rotate"`

startLock sync.Mutex // Only one log can write to the file

Level int `json:"level"`
}

// MuxWriter an *os.File writer with locker.
type MuxWriter struct {
sync.Mutex
fd *os.File
}

// write to os.File.
func (l *MuxWriter) Write(b []byte) (int, error) {
l.Lock()
defer l.Unlock()
return l.fd.Write(b)
}

// SetFd set os.File in writer.
func (l *MuxWriter) SetFd(fd *os.File) {
if l.fd != nil {
_ = l.fd.Close()
}
l.fd = fd
}

// NewFileWriter create a FileLogWriter returning as LoggerInterface.
func NewFileWriter() LoggerInterface {
w := &LogWriter{
Filename: "",
Maxlines: 1000000,
Maxsize: 1 << 28, //256 MB
Daily:  true,
Maxdays: 7,
Rotate:  true,
Level:  LevelDebug,
}
// use MuxWriter instead direct use os.File for lock write when rotate
w.mw = new(MuxWriter)
// set MuxWriter as Logger's io.Writer
w.Logger = log.New(w.mw, "", log.Ldate|log.Ltime)
return w
}

// Init file logger with json config.
// jsonconfig like:
// {
// "filename":"logs/sample.log",
// "maxlines":10000,
// "maxsize":1<<30,
// "daily":true,
// "maxdays":15,
// "rotate":true
// }
func (w *LogWriter) Init(jsonconfig string) error {
err := json.Unmarshal([]byte(jsonconfig), w)
if err != nil {
return err
}
if len(w.Filename) == 0 {
return errors.New("jsonconfig must have filename")
}
err = w.startLogger()
return err
}

// start file logger. create log file and set to locker-inside file writer.
func (w *LogWriter) startLogger() error {
fd, err := w.createLogFile()
if err != nil {
return err
}
w.mw.SetFd(fd)
err = w.initFd()
if err != nil {
return err
}
return nil
}

func (w *LogWriter) docheck(size int) {
w.startLock.Lock()
defer w.startLock.Unlock()
if w.Rotate && ((w.Maxlines > 0 && w.maxlinesCurlines >= w.Maxlines) ||
(w.Maxsize > 0 && w.maxsizeCursize >= w.Maxsize) ||
(w.Daily && time.Now().Day() != w.dailyOpendate)) {
if err := w.DoRotate(); err != nil {
 fmt.Fprintf(os.Stderr, "FileLogWriter(％q): ％s\n", w.Filename, err)
 return
}
}
w.maxlinesCurlines++
w.maxsizeCursize += size
}

// WriteMsg write logger message into file.
func (w *LogWriter) WriteMsg(msg string, level int) error {
if level > w.Level {
return nil
}
n := 24 + len(msg) // 24 stand for the length "2013/06/23 21:00:22 [T] "
w.docheck(n)
w.Logger.Print(msg)
return nil
}

func (w *LogWriter) createLogFile() (*os.File, error) {
// Open the log file
fd, err := os.OpenFile(w.Filename, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0660)
return fd, err
}

func (w *LogWriter) initFd() error {
fd := w.mw.fd
finfo, err := fd.Stat()
if err != nil {
return fmt.Errorf("get stat err: ％s", err)
}
w.maxsizeCursize = int(finfo.Size())
w.dailyOpendate = time.Now().Day()
if finfo.Size() > 0 {
content, err := ioutil.ReadFile(w.Filename)
if err != nil {
 return err
}
w.maxlinesCurlines = len(strings.Split(string(content), "\n"))
} else {
w.maxlinesCurlines = 0
}
return nil
}

// DoRotate means it need to write file in new file.
// new file name like xx.log.2013-01-01.2
func (w *LogWriter) DoRotate() error {
_, err := os.Lstat(w.Filename)
if err == nil { // file exists
// Find the next available number
num := 1
fname := ""
for ; err == nil && num <= 999; num++ {
 fname = w.Filename + fmt.Sprintf(".％s.％03d", time.Now().Format("2006-01-02"), num)
 _, err = os.Lstat(fname)
}
// return error if the last file checked still existed
if err == nil {
 return fmt.Errorf("Rotate: Cannot find free log number to rename ％s", w.Filename)
}

// block Logger's io.Writer
w.mw.Lock()
defer w.mw.Unlock()

fd := w.mw.fd
_ = fd.Close()

// close fd before rename
// Rename the file to its newfound home
err = os.Rename(w.Filename, fname)
if err != nil {
 return fmt.Errorf("Rotate: ％s", err)
}

// re-start logger
err = w.startLogger()
if err != nil {
 return fmt.Errorf("Rotate StartLogger: ％s", err)
}

go w.deleteOldLog()
}

return nil
}

func (w *LogWriter) deleteOldLog() {
dir := filepath.Dir(w.Filename)
_ = filepath.Walk(dir, func(path string, info os.FileInfo, err error) (returnErr error) {
defer func() {
 if r := recover(); r != nil {
 returnErr = fmt.Errorf("Unable to delete old log '％s', error: ％+v", path, r)
 fmt.Println(returnErr)
 }
}()

if !info.IsDir() && info.ModTime().Unix() < (time.Now().Unix()-60*60*24*w.Maxdays) {
 if strings.HasPrefix(filepath.Base(path), filepath.Base(w.Filename)) {
 _ = os.Remove(path)
 }
}
return
})
}

// Destroy destroy file logger, close file writer.
func (w *LogWriter) Destroy() {
_ = w.mw.fd.Close()
}

// Flush file logger.
// there are no buffering messages in file logger in memory.
// flush file means sync file from disk.
func (w *LogWriter) Flush() {
_ = w.mw.fd.Sync()
}

补充知识：golang logrus自定义hook:日志切片hook、邮件警报hook、kafkahook

logrus Hook 分析

logrus hook 接口定义很简单。如下

package logrus

// A hook to be fired when logging on the logging levels returned from
// `Levels()` on your implementation of the interface. Note that this is not
// fired in a goroutine or a channel with workers, you should handle such
// functionality yourself if your call is non-blocking and you don't wish for
// the logging calls for levels returned from `Levels()` to block.
type Hook interface {
Levels() []Level
Fire(*Entry) error
}

// Internal type for storing the hooks on a logger instance.
type LevelHooks map[Level][]Hook

// Add a hook to an instance of logger. This is called with
// `log.Hooks.Add(new(MyHook))` where `MyHook` implements the `Hook` interface.
func (hooks LevelHooks) Add(hook Hook) {
for _, level := range hook.Levels() {
hooks[level] = append(hooks[level], hook)
}
}

// Fire all the hooks for the passed level. Used by `entry.log` to fire
// appropriate hooks for a log entry.
func (hooks LevelHooks) Fire(level Level, entry *Entry) error {
for _, hook := range hooks[level] {
if err := hook.Fire(entry); err != nil {
 return err
}
}
return nil
}

只需实现 该结构的接口。

type Hook interface {
Levels() []Level
Fire(*Entry) error
}

就会被logrus框架遍历调用已注册的 hook 的 Fire 方法

获取日志实例

// log_hook.go
package logger

import (
"fmt"
"github.com/sirupsen/logrus"
"library/util/constant"
"os"
)

//自实现 logrus hook
func getLogger(module string) *logrus.Logger {
//实例化
logger := logrus.New()
//设置输出
logger.Out = os.Stdout
//设置日志级别
logger.SetLevel(logrus.DebugLevel)
//设置日志格式
//自定writer就行， hook 交给 lfshook
logger.AddHook(newLogrusHook(constant.GetLogPath(), module))

logger.SetFormatter(&logrus.JSONFormatter{
TimestampFormat:"2006-01-02 15:04:05",
})
return logger
}

//确保每次调用使用的文件都是唯一的。
func GetNewFieldLoggerContext(module,appField string) *logrus.Entry {
logger:= getLogger(module)
return logger.WithFields(logrus.Fields{
"app": appField,
})
}

//订阅 警告日志
func SubscribeLog(entry *logrus.Entry, subMap SubscribeMap) {
logger := entry.Logger
logger.AddHook(newSubScribeHook(subMap))
fmt.Println("日志订阅成功")
}

constant.GetLogPath() 可以替换为自己的日志文件输出目录地址，比如我的mac上则是：/usr/local/log ,直接替换即可。

日志切片hook

代码

// writer.go
package logger

import (
"fmt"
"github.com/pkg/errors"
"io"
"library/util"
"os"
"path/filepath"
"sync"
"time"
)

type LogWriter struct {
logDir       string //日志根目录地址。
module       string //模块 名
 curFileName   string //当前被指定的filename
curBaseFileName   string //在使用中的file
turnCateDuration  time.Duration
mutex      sync.RWMutex
outFh      *os.File
}

func (w *LogWriter) Write(p []byte) (n int, err error) {
w.mutex.Lock()
defer w.mutex.Unlock()
if out, err:= w.getWriter(); err!=nil {
return 0, errors.New("failed to fetch target io.Writer")
}else{
return out.Write(p)
}
}

func (w *LogWriter) getFileName() string {
base := time.Now().Truncate(w.turnCateDuration)
return fmt.Sprintf("％s/％s/％s_％s", w.logDir, base.Format("2006-01-02"), w.module, base.Format("15"))
}

func (w *LogWriter) getWriter()(io.Writer, error) {
fileName := w.curBaseFileName
//判断是否有新的文件名
//会出现新的文件名
baseFileName := w.getFileName()
if baseFileName != fileName {
fileName = baseFileName
}

dirname := filepath.Dir(fileName)
if err := os.MkdirAll(dirname, 0755); err != nil {
return nil, errors.Wrapf(err, "failed to create directory ％s", dirname)
}

fileHandler, err := os.OpenFile(fileName, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
if err != nil {
return nil, errors.Errorf("failed to open file ％s", err)
}
w.outFh.Close()
w.outFh = fileHandler
w.curBaseFileName = fileName
w.curFileName = fileName

return fileHandler, nil
}

func New(logPath, module string, duration time.Duration) *LogWriter {
return &LogWriter{
logDir: logPath,
module: module,
turnCateDuration:duration,
curFileName: "",
curBaseFileName: "",
}
}

// hook.go
package logger

import (
"github.com/rifflock/lfshook"
"github.com/sirupsen/logrus"
"time"
)
func newLogrusHook(logPath, moduel string) logrus.Hook {
logrus.SetLevel(logrus.WarnLevel)

writer := New(logPath, moduel, time.Hour * 2)

lfsHook := lfshook.NewHook(lfshook.WriterMap{
logrus.DebugLevel: writer,
logrus.InfoLevel: writer,
logrus.WarnLevel: writer,
logrus.ErrorLevel: writer,
logrus.FatalLevel: writer,
logrus.PanicLevel: writer,
}, &logrus.TextFormatter{DisableColors: true})

// writer 生成新的log文件类型 writer 在通过new hook函数 消费 fire 函数
// writer 是实现了writer 接口的库，在日志调用write是做预处理
return lfsHook
}

测试代码

func TestGetLogger(t *testing.T) {
lg := GetNewFieldLoggerContext("test","d")
lg.Logger.Info("????")
}

解析

logger实例持有了 自定义的 io.writer 结构体，在消费Fire函数时，会调用Write方法，此时通过Truncate时间切片函数逻辑判断需要写入的文件。或创建新的文件。

注: 文章提供的代码是按天切分文件夹的，文件夹内模块日志再按2小时切分。可自行替换成按模块切分。

邮件警报hook

代码

// subscribeHook.go
package logger

import (
"fmt"
"github.com/sirupsen/logrus"
"library/email"
"strings"
)

type SubscribeMap map[logrus.Level][]*email.Receiver
type SubscribeHook struct {
subMap SubscribeMap
}
//此处可以自实现hook 目前使用三方hook
func(h *SubscribeHook)Levels() []logrus.Level{
return logrus.AllLevels
}

func(h *SubscribeHook)Fire(entry *logrus.Entry) error{
for level, receivers := range h.subMap {
//命中 准备消费
if level == entry.Level {
 if len(receivers) > 0 {
 email.SendEmail(receivers, fmt.Sprintf("％s:[系统日志警报]", entry.Level.String()),
  fmt.Sprintf("错误内容: ％s",entry.Message))
 }
}
}
return nil
}
func NewSubscribeMap(level logrus.Level, receiverStr string) SubscribeMap{
subMap := SubscribeMap{}
addressList := strings.Split(receiverStr,";")
var receivers []*email.Receiver
for _, address := range addressList {
receivers = append(receivers, &email.Receiver{Email: address})
}
subMap[level] = receivers
return subMap
}
func newSubScribeHook(subMap SubscribeMap) *SubscribeHook {
return &SubscribeHook{subMap}

// email.go
package email

import (
"fmt"
"gopkg.in/gomail.v2"
"regexp"
"strconv"
)

type Sender struct {
User   string
Password string
Host   string
Port   int
MailTo  []string
Subject  string
Content  string
}

type Receiver struct {
Email  string
}

func (r *Receiver) Check() bool {
pattern := `\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*` //匹配电子邮箱
reg := regexp.MustCompile(pattern)
return reg.MatchString(r.Email)
}

func (s *Sender) clean (){

}

//检查 邮箱正确性
func (s *Sender)NewReceiver(email string) *Receiver {
rec := &Receiver{Email:email}
if rec.Check() {
m.MailTo = []string{email}
return rec
}else{
fmt.Printf("email check fail 【％s】\n", email)
return nil
}
}
func (s *Sender)NewReceivers(receivers []*Receiver) {
for _, rec := range receivers {
if rec.Check() {
 m.MailTo = append(m.MailTo, rec.Email)
}else{
 fmt.Printf("email check fail 【％s】\n", rec.Email)
}
}
}
// 163邮箱 password 为开启smtp后给的秘钥
var m = Sender{User:"6666666@163.com", Password:"666666666", Host: "smtp.163.com", Port: 465}

func SendEmail(receivers []*Receiver,subject, content string){
m.NewReceivers(receivers)
m.Subject = subject
m.Content = content

e := gomail.NewMessage()
e.SetHeader("From", e.FormatAddress(m.User, "hengsheng"))
e.SetHeader("To", m.MailTo...)  //发送给多个用户
e.SetHeader("Subject", m.Subject) //设置邮件主题
e.SetBody("text/html", m.Content)  //设置邮件正文
d := gomail.NewDialer(m.Host, m.Port, m.User, m.Password)
err := d.DialAndSend(e)
if err != nil {
fmt.Printf("error 邮件发送错误! ％s \n", err.Error())
}
}

使用

同理在writer时 如果是错误日志则发送邮件。

o.logger = logger.GetNewFieldLoggerContext("test", "666")
if subscribeSocket {
logger.SubscribeLog(o.Logger, logger.NewSubscribeMap(logrus.ErrorLevel, "a@163.com;b@163.com"))
}
// o 为实际结构体实例

kafkahook

// kafka hook
package logger

import (
"github.com/sirupsen/logrus"
"library/kafka"
"library/util/constant"
)

type KafKaHook struct {
kafkaProducer  *kafka.KafkaProducer
}

func(h *KafKaHook)Levels() []logrus.Level{
return logrus.AllLevels
}

func(h *KafKaHook)Fire(entry *logrus.Entry) error{
h.kafkaProducer.SendMsgSync(entry.Message)
return nil
}

func newKafkaHook() *KafKaHook{
producer := kafka.NewKafkaProducer(constant.KafkaLogElkTopic,true)
return &KafKaHook{kafkaProducer: producer}
}

使用时logger.AddHook(newKafkaHook()) 即可

kafka模块

生产者

// kafkaProducer.go
package kafka

import (
"errors"
"fmt"
"github.com/Shopify/sarama"
"library/util/constant"
"log"
"time"
)

func GetKafkaAddress()[]string{
return "127.0.0.1:9092"
}

//同步消息模式
func SyncProducer(topic, message string) error {
config := sarama.NewConfig()
config.Producer.Return.Successes = true
config.Producer.Timeout = 5 * time.Second
p, err := sarama.NewSyncProducer(GetKafkaAddress(), config)
if err != nil {
return errors.New(fmt.Sprintf("sarama.NewSyncProducer err, message=％s \n", err))
}
defer p.Close()
msg := &sarama.ProducerMessage{
Topic: topic,
Value: sarama.ByteEncoder(message),
}
part, offset, err := p.SendMessage(msg)
if err != nil {
return errors.New(fmt.Sprintf("send sdsds err=％s \n", err))
} else {
fmt.Printf("发送成功，partition=％d, offset=％d \n", part, offset)
return nil
}
}

//async 异步生产者
type KafkaProducer struct {
topic    string
asyncProducer  *sarama.AsyncProducer
syncProducer  *sarama.SyncProducer
sync    bool
}

func NewKafkaProducer(topic string, sync bool) *KafkaProducer {
k := &KafkaProducer{
topic:   topic,
sync:   sync,
}
if sync {
k.initSync()
}else{
k.initAsync()
}
return k
}

func (k *KafkaProducer) initAsync() bool {
if k.sync {
fmt.Printf("sync producer cant call async func ！\n")
return false
}
config := sarama.NewConfig()
//等待服务器所有副本都保存成功后的响应
config.Producer.RequiredAcks = sarama.WaitForAll
//随机向partition发送消息
config.Producer.Partitioner = sarama.NewRandomPartitioner
//是否等待成功和失败后的响应,只有上面的RequireAcks设置不是NoReponse这里才有用.
config.Producer.Return.Successes = true
config.Producer.Return.Errors = true
//设置使用的kafka版本,如果低于V0_10_0_0版本,消息中的timestrap没有作用.需要消费和生产同时配置
//注意，版本设置不对的话，kafka会返回很奇怪的错误，并且无法成功发送消息
config.Version = sarama.V0_10_0_1

producer, e := sarama.NewAsyncProducer(GetKafkaAddress(), config)
if e != nil {
fmt.Println(e)
return false
}
k.asyncProducer = &producer
defer producer.AsyncClose()
pd := *k.asyncProducer
go func() {
for{
 select {
 case <-pd.Successes():
 //fmt.Println("offset: ", suc.Offset, "timestamp: ", suc.Timestamp.String(), "partitions: ", suc.Partition)
 case fail := <-pd.Errors():
 fmt.Printf("err: ％s \n", fail.Err.Error())
 }
}
}()

return true
}

func (k *KafkaProducer) initSync() bool {
if !k.sync {
fmt.Println("async producer cant call sync func ！")
return false
}

config := sarama.NewConfig()
config.Producer.Return.Successes = true
config.Producer.Timeout = 5 * time.Second
p, err := sarama.NewSyncProducer(GetKafkaAddress(), config)
k.syncProducer = &p
if err != nil {
log.Printf("sarama.NewSyncProducer err, message=％s \n", err)
return false
}
return true
}

func (k *KafkaProducer) SendMsgAsync(sendStr string) {

msg := &sarama.ProducerMessage{
Topic: k.topic,
}

//将字符串转化为字节数组
msg.Value = sarama.ByteEncoder(sendStr)
//fmt.Println(value)

//使用通道发送
pd := *k.asyncProducer
pd.Input() <- msg
}

func (k *KafkaProducer) SendMsgSync(sendStr string) bool {
msg := &sarama.ProducerMessage{
Topic: k.topic,
Value: sarama.ByteEncoder(sendStr),
}
pd := *k.syncProducer
part, offset, err := pd.SendMessage(msg)
if err != nil {
fmt.Printf("发送失败 send message(％s) err=％s \n", sendStr, err)
return false
} else {
fmt.Printf("发送成功 partition=％d, offset=％d \n", part, offset)
return true
}
}

调用 SendMsgSync 或 SendMsgAsync 生产消息，注意初始化时的参数要保证一致！

消费者组

// kafkaConsumerGroup.go

package kafka

import (
"context"
"fmt"
"github.com/Shopify/sarama"
"log"
"sync"
)

func NewKafkaConsumerGroup(topics []string, group string, businessCall func(message *sarama.ConsumerMessage) bool) *KafkaConsumerGroup {
k := &KafkaConsumerGroup{
brokers:  GetKafkaAddress(),
topics:  topics,
group:       group,
channelBufferSize: 2,
ready:       make(chan bool),
version:  "1.1.1",
handler:  businessCall,
}
k.Init()
return k
}

// 消费者组(consumer group): 相同的group.id的消费者将视为同一个消费者组,
// 每个消费者都需要设置一个组id, 每条消息只能被 consumer group 中的一个
// Consumer 消费,但可以被多个 consumer group 消费
type KafkaConsumerGroup struct {
//代理(broker): 一台kafka服务器称之为一个broker
brokers   []string
//主题(topic): 消息的一种逻辑分组，用于对消息分门别类，每一类消息称之为一个主题，相同主题的消息放在一个队列中
topics    []string
version   string
ready       chan bool
group       string
channelBufferSize  int
//业务调用
handler     func(message *sarama.ConsumerMessage) bool
}

func (k *KafkaConsumerGroup)Init() func() {

version,err := sarama.ParseKafkaVersion(k.version)
if err!=nil{
fmt.Printf("Error parsing Kafka version: ％v", err)
}
cfg := sarama.NewConfig()
cfg.Version = version
// 分区分配策略
cfg.Consumer.Group.Rebalance.Strategy = sarama.BalanceStrategyRange
// 未找到组消费位移的时候从哪边开始消费
cfg.Consumer.Offsets.Initial = -2
// channel长度
cfg.ChannelBufferSize = k.channelBufferSize
ctx, cancel := context.WithCancel(context.Background())
client, err := sarama.NewConsumerGroup(k.brokers, k.group, cfg)
if err != nil {
 fmt.Printf("Error creating consumer group client: ％v", err)
}

wg := &sync.WaitGroup{}
wg.Add(1)
go func() {
 defer func() {
 wg.Done()
 //util.HandlePanic("client.Consume panic", log.StandardLogger())
 }()
 for {
 if err := client.Consume(ctx, k.topics, k); err != nil {
  log.Printf("Error from consumer: ％v", err)
 }
 // check if context was cancelled, signaling that the consumer should stop
 if ctx.Err() != nil {
  log.Println(ctx.Err())
  return
 }
 k.ready = make(chan bool)
 }
}()

<-k.ready
fmt.Printf("Sarama consumer up and running!... \n")
// 保证在系统退出时，通道里面的消息被消费
return func() {
 cancel()
 wg.Wait()
 if err = client.Close(); err != nil {
 fmt.Printf("Error closing client: ％v \n", err)
 }
}

}

// Setup is run at the beginning of a new session, before ConsumeClaim
func (k *KafkaConsumerGroup) Setup(sarama.ConsumerGroupSession) error {
// Mark the consumer as ready
close(k.ready)
return nil
}

// Cleanup is run at the end of a session, once all ConsumeClaim goroutines have exited
func (k *KafkaConsumerGroup) Cleanup(sarama.ConsumerGroupSession) error {
return nil
}

// ConsumeClaim must start a consumer loop of ConsumerGroupClaim's Messages().
func (k *KafkaConsumerGroup) ConsumeClaim(session sarama.ConsumerGroupSession, claim sarama.ConsumerGroupClaim) error {

// NOTE:
// Do not move the code below to a goroutine.
// The `ConsumeClaim` itself is called within a goroutine, see:
// https://github.com/Shopify/sarama/blob/master/consumer_group.go#L27-L29
// 具体消费消息
for message := range claim.Messages() {
//msg := string(message.Value)
//k.logger.Infof("卡夫卡: ％s", msg)

if ok:= k.handler(message); ok {
 // 更新位移
 session.MarkMessage(message, "")
}
//run.Run(msg)
}
return nil
}

测试代码

func TestKafkaConsumerGroup_Init(t *testing.T) {
//pd := NewKafkaProducer("test-fail",true)
//pd.InitSync()
k := NewKafkaConsumerGroup([]string{constant.KafkaALiSdkTopic}, "group-2", func(message *sarama.ConsumerMessage) bool {
fmt.Println(string(message.Value))
//如果失败的处理逻辑
//if ok := pd.SendMsgSync("666666"); ok {
// return true
//}
return false

})
consumerDone := k.Init()

sigterm := make(chan os.Signal, 1)
signal.Notify(sigterm, syscall.SIGINT, syscall.SIGTERM)
select {
case <-sigterm:
fmt.Println("terminating: via signal")
}
consumerDone()
}

这里有一些补偿逻辑在里面。

来源：https://noshoes.blog.csdn.net/article/details/82909121