go语言并发实战——日志收集系统(十) 重构tailfile模块实现同时监控多个日志文件

前言

在上一篇文章中，我们实现了通过etcd来同时指定多个不同的有关分区与日志文件的路径，但是锁着一次读取配置的增多，不可避免的出现了一个问题：我们如何来监控多个日志文件，这样原来的tailFile模块相对于当下场景就显得有些捉襟见肘了，所以对tialFile模块进行重构就成了我们必须要做的事情了。

TailFiile模块的重构流程

储存数据结构体的重构

在上一篇博文中我们定义了collectEntry来储存我们从etcd中get到的信息，但是，这个获取的消息在tailFile模块也需要使用，所以这里我们再创建一个common模块来专门储存这个数据：

type CollectEntry struct {
	Path  string `json:"path"`
	Topic string `json:"topic"`
}

在tailFile模块中也需要一个结构体来储存需要的信息：

type tailTask struct{
	path string
	topic string
	TailObj *tail.Tail
}

tail初始化模块的重构

由于现在我们的配置信息全部储存到了 CollectEntry结构体中，它会给tail的初始化函数传递一个CollectEntry结构体数组，所以我们需要对之前的tail模块代码进行重构与细化，如下：

type tailTask struct {
	path    string
	topic   string
	TailObj *tail.Tail
}

func NewTailTask(path, topic string) (tt *tailTask) {
	tt = &tailTask{
		path:  path,
		topic: topic,
	}
	return tt
}

func (task *tailTask) Init() (err error) {
	config := tail.Config{
		Follow:    true,
		ReOpen:    true,
		MustExist: true,
		Poll:      true,
		Location:  &tail.SeekInfo{Offset: 0, Whence: 2},
	}
	task.TailObj, err = tail.TailFile(task.path, config)
	if err != nil {
		logrus.Error("tail create tailObj for path:%s,err:%v", task.path, err)
		return
	}
	return
}

func InitTail(collectEntryList []common.CollectEntry) (err error) {
	for _, entry := range collectEntryList {
		tt := NewTailTask(entry.Path, entry.Topic)
		err = tt.Init()
		if err != nil {
			logrus.Error("tail create tailObj for path:%s,err:%v", entry.Path, err)
			continue
		}
		go tt.run()
	}
	return
}

之前我们只有一个日志需要监控，所以主要的工作流程可以放在man.go中，但是现在会创建多个tailTask来监控，我们最好将他移动到tail模块中，最后tail模块的全部代码为：

package tailFile

import (
	"github.com/Shopify/sarama"
	"github.com/Shopify/toxiproxy/Godeps/_workspace/src/github.com/Sirupsen/logrus"
	"github.com/hpcloud/tail"
	"log-agent/Kafka"
	"log-agent/common"
	"strings"
	"time"
)

type tailTask struct {
	path    string
	topic   string
	TailObj *tail.Tail
}

func NewTailTask(path, topic string) (tt *tailTask) {
	tt = &tailTask{
		path:  path,
		topic: topic,
	}
	return tt
}

func (task *tailTask) Init() (err error) {
	config := tail.Config{
		Follow:    true,
		ReOpen:    true,
		MustExist: true,
		Poll:      true,
		Location:  &tail.SeekInfo{Offset: 0, Whence: 2},
	}
	task.TailObj, err = tail.TailFile(task.path, config)
	if err != nil {
		logrus.Error("tail create tailObj for path:%s,err:%v", task.path, err)
		return
	}
	return
}

func InitTail(collectEntryList []common.CollectEntry) (err error) {
	for _, entry := range collectEntryList {
		tt := NewTailTask(entry.Path, entry.Topic)
		err = tt.Init()
		if err != nil {
			logrus.Error("tail create tailObj for path:%s,err:%v", entry.Path, err)
			continue
		}
		go tt.run()
	}
	return
}

func (t *tailTask) run() {
	for {
		line, ok := <-t.TailObj.Lines
		if !ok {
			logrus.Warn("tailFile.TailObj.Lines channel closed,path:%s\n", t.path)
			time.Sleep(2 * time.Second)
			continue
		}
		if len(strings.Trim(line.Text, "\r")) == 0 {
			continue
		}
		msg := &sarama.ProducerMessage{}
		msg.Topic = t.topic
		msg.Value = sarama.StringEncoder(line.Text)
		Kafka.MesChan(msg)
	}
}

修改模块的全部代码

main.go

package main

import (
	"fmt"
	"github.com/Shopify/toxiproxy/Godeps/_workspace/src/github.com/Sirupsen/logrus"
	"github.com/go-ini/ini"
	"log-agent/Kafka"
	"log-agent/etcd"
	"log-agent/tailFile"
)

type Config struct {
	Kafakaddress Kafkaddress `ini:"kafka"`
	LogFilePath  LogFilePath `ini:"collect"`
	Etcdaddress  EtcdAddress `ini:"etcd"`
}

type Kafkaddress struct {
	Addr        []string `ini:"address"`
	Topic       string   `ini:"topic"`
	MessageSize int64    `ini:"chan_size"`
}

type LogFilePath struct {
	Path string `ini:"logfile_path"`
}

type EtcdAddress struct {
	Addr []string `ini:"address"`
	Key  string   `ini:"collect_key"`
}

func run() {
	select {}
}

func main() {
	//读取配置文件，获取配置信息
	filename := "G:\\goproject\\-goroutine-\\log-agent\\conf\\config.ini"
	ConfigObj := new(Config)
	err := ini.MapTo(ConfigObj, filename)
	if err != nil {
		logrus.Error("%s Load failed,err:", filename, err)
	}

	//初始化Kafka
	err = Kafka.InitKafka(ConfigObj.Kafakaddress.Addr, ConfigObj.Kafakaddress.MessageSize)
	if err != nil {
		logrus.Error("InitKafka failed, err:%v", err)
		return
	}
	logrus.Infof("InitKafka success")

	//初始化etcd
	err = etcd.Init(ConfigObj.Etcdaddress.Addr)
	if err != nil {
		logrus.Error("InitEtcd failed, err:%v", err)
		return
	}
	logrus.Infof("InitEtcd success")

	//拉取要收集日志文件的配置项
	err, collectEntryList := etcd.GetConf(ConfigObj.Etcdaddress.Key)
	if err != nil {
		logrus.Error("GetConf failed, err:%v", err)
		return
	}
	fmt.Println(collectEntryList)
	//初始化tail

	err = tailFile.InitTail(collectEntryList)
	if err != nil {
		logrus.Error("InitTail failed, err:%v", err)
		return
	}
	logrus.Infof("InitTail success")
	run()
}

common.go

package common

type CollectEntry struct {
	Path  string `json:"path"`
	Topic string `json:"topic"`
}

tailFile.go

package tailFile

import (
	"github.com/Shopify/sarama"
	"github.com/Shopify/toxiproxy/Godeps/_workspace/src/github.com/Sirupsen/logrus"
	"github.com/hpcloud/tail"
	"log-agent/Kafka"
	"log-agent/common"
	"strings"
	"time"
)

type tailTask struct {
	path    string
	topic   string
	TailObj *tail.Tail
}

func NewTailTask(path, topic string) (tt *tailTask) {
	tt = &tailTask{
		path:  path,
		topic: topic,
	}
	return tt
}

func (task *tailTask) Init() (err error) {
	config := tail.Config{
		Follow:    true,
		ReOpen:    true,
		MustExist: true,
		Poll:      true,
		Location:  &tail.SeekInfo{Offset: 0, Whence: 2},
	}
	task.TailObj, err = tail.TailFile(task.path, config)
	if err != nil {
		logrus.Error("tail create tailObj for path:%s,err:%v", task.path, err)
		return
	}
	return
}

func InitTail(collectEntryList []common.CollectEntry) (err error) {
	for _, entry := range collectEntryList {
		tt := NewTailTask(entry.Path, entry.Topic)
		err = tt.Init()
		if err != nil {
			logrus.Error("tail create tailObj for path:%s,err:%v", entry.Path, err)
			continue
		}
		go tt.run()
	}
	return
}

func (t *tailTask) run() {
	for {
		line, ok := <-t.TailObj.Lines
		if !ok {
			logrus.Warn("tailFile.TailObj.Lines channel closed,path:%s\n", t.path)
			time.Sleep(2 * time.Second)
			continue
		}
		if len(strings.Trim(line.Text, "\r")) == 0 {
			continue
		}
		msg := &sarama.ProducerMessage{}
		msg.Topic = t.topic
		msg.Value = sarama.StringEncoder(line.Text)
		Kafka.MesChan(msg)
	}
}