嵌入式linux之go語言開發（六）幾行代碼實現終端的遠程日誌診斷

日誌是應用的鏡子，可以發現應用中的問題，重要性不言而喻。

以往設備有問題了，是如何診斷的？我們是現場人員到現場，又是配合抓包，又是配合提供機器日誌，效率極其低下。

如今都物聯網時代了，能讓數據跑路的還讓人去跑路，不合適吧。

日誌應能實現手工觸發上送，或應用中出現嚴重問題時主動上送，或者遠程控制其是否上送。

試想，如果能讓問題出現在被客戶發現之前，提前被開發人員獲知，主動的解決問題，那麼無疑提高了產品的競爭力和口碑。爲杜絕問題造成的嚴重性而未及時發現提供先機。

當某天發現一機器偶然吐出一異常的bug日誌時，且這日誌暴露的問題若不解決將造成嚴重後果，而你恰好在你的郵箱裏看到，這就在不知不覺中主動發現了問題。不用運維人員去找你，客戶去找你，機器向你求救了。那麼，救救它吧。

以下爲在嵌入式linux上實現的一小功能，對終端產生的日誌文件進行zip壓縮並上送到後臺FTP服務器中。

幾行代碼，輕鬆實現。又一次體現使用 go開發嵌入式linux應用的強大之處。

若要用c去做，那麼呵呵，可以試試。

package main

import (
	"archive/zip"
	"flag"
	"fmt"
	"io"
	"log"
	"os"
	"strings"

	"github.com/dutchcoders/goftp"
	"github.com/larspensjo/config"
)

var (
	ftp     *goftp.FTP
	conFile        = flag.String("ftpcfg", "/ftpcfg.ini", "config file")
	Server  string = "127.0.0.1:21"
	User    string = ""
	Pwd     string = ""
)

func checkErr(err error) {
	if err != nil {
		fmt.Fprintf(os.Stderr, "Fatal error: %s", err.Error())
	}
}

/**
@files：需要壓縮的文件
@compreFile：壓縮之後的文件
*/
func CompressZip(files []*os.File, zipfileName string) (err error) {
	zipfile, err := os.Create(zipfileName)
	if err != nil {
		return err
	}
	defer zipfile.Close()

	zw := zip.NewWriter(zipfile)
	defer zw.Close()
	for _, file := range files {
		err := compressZip(file, zw)
		if err != nil {
			return err
		}
		file.Close()
	}
	return nil
}

/**
功能：壓縮文件
@file:壓縮文件
@prefix：壓縮文件內部的路徑
@tw：寫入壓縮文件的流
*/
func compressZip(file *os.File, zw *zip.Writer) error {
	info, err := file.Stat()
	if err != nil {
		log.Println("壓縮文件失敗：", err.Error())
		return err
	}
	log.Println("filesize:", info.Size()/1024, "kb")
	// 獲取壓縮頭信息
	head, err := zip.FileInfoHeader(info)
	if err != nil {
		log.Println("壓縮文件失敗：", err.Error())
		return err
	}
	// 指定文件壓縮方式 默認爲 Store 方式 該方式不壓縮文件 只是轉換爲zip保存
	head.Method = zip.Deflate
	fw, err := zw.CreateHeader(head)
	if err != nil {
		log.Println("壓縮文件失敗：", err.Error())
		return err
	}
	// 寫入文件到壓縮包中
	_, err = io.Copy(fw, file)
	file.Close()
	if err != nil {
		log.Println("壓縮文件失敗：", err.Error())
		return err
	}
	return nil
}

func main() {

	log.Println("Hello Go")
	defer func() {
		if r := recover(); r != nil {
			log.Printf("crash occurred!capture：%s\n", r)
		}
	}()
	var fname string
	flag.StringVar(&fname, "fname", "", "file name")
	flag.Parse()
	flag.Usage()
	//獲取當前路徑
	file, _ := os.Getwd()
	cfg, err := config.ReadDefault(file + *conFile)
	checkErr(err)
	//獲取配置文件中的配置項
	Server, err = cfg.String("SERVERCONFIG", "Server")

	User, err = cfg.String("USER", "User")
	Pwd, err = cfg.String("USER", "Pwd")

	//壓縮ZIP
	var filezips []*os.File
	var filezip *os.File
	if filezip, err = os.Open(fname); err != nil {
		panic(err)
	}
	filezips = append(filezips, filezip)
	log.Println("begin compressZip...")
	err = CompressZip(filezips, fname+".zip")
	if err != nil {
		panic(err)
	}
	log.Println("compressZip ok!,name=" + fname + ".zip")
	log.Println("User:" + User)
	log.Println("->begin connect server:" + Server)
	// For debug messages: goftp.ConnectDbg("ftp.server.com:21")
	if ftp, err = goftp.ConnectDbg(Server); err != nil {
		panic(err)
	}
	//ftp.debug = true
	defer ftp.Close()
	log.Println("->Successfully connected !!")

	// Username / password authentication
	if err = ftp.Login(User, Pwd); err != nil {
		panic(err)
	}
	log.Println("->Login success!")
	if err = ftp.Cwd("/"); err != nil {
		panic(err)
	}

	var curpath string
	if curpath, err = ftp.Pwd(); err != nil {
		panic(err)
	}

	log.Printf("Current path: %s\n", curpath)

	// Upload a file
	var fileup *os.File
	if fileup, err = os.Open(fname + ".zip"); err != nil {
		panic(err)
	}
	log.Println("->begin upload file...")
	info, err := fileup.Stat()
	if err != nil {
		panic(err)
	}
	log.Println("upload filesize:", info.Size()/1024, "kb")
	fpath := fname + ".zip"
	lastidx := strings.LastIndex(fname+".zip", "/")
	if lastidx != -1 {
		fpath = fname[lastidx:] + ".zip"
	}
	log.Printf("fpath:%s\n", fpath)
	if err := ftp.Stor(fpath, fileup); err != nil {
		panic(err)
	}
	log.Println("->upload file over!")
	err = os.Remove(fname + ".zip") //上傳成功，刪除zip文件
	if err != nil {
		log.Println("file remove Error!")
		panic(err)
	}

}

編譯與使用：

GOOS=linux GOARCH=arm GOARM=7 go build ftp.go
ftp -fname=/log/log_b503_20190730.log

root@b_lcd:/app/opt
./ftp -fname=/log/log_b503_20190730.log

Hello Go
Usage of ./ftp:
  -fname string
        file name
  -ftpcfg string
        config file (default "/ftpcfg.ini")
User:qq8864
->begin connect server:015.3vftp.com:21
2019/07/30 17:44:08 begin receiveLine...
2019/07/30 17:44:09 < 220 Serv-U FTP Server v6.4 for WinSock ready...
2019/07/30 17:44:09 receiveLine over!
2019/07/30 17:44:09 220 Serv-U FTP Server v6.4 for WinSock ready...
->Successfully connected !!
2019/07/30 17:44:09 > USER qq8864
2019/07/30 17:44:09 begin receiveLine...
2019/07/30 17:44:09 < 331 User name okay, need password.
2019/07/30 17:44:09 receiveLine over!
2019/07/30 17:44:09 > PASS sars1212
2019/07/30 17:44:09 begin receiveLine...
2019/07/30 17:44:09 < 230 User logged in, proceed.
2019/07/30 17:44:09 receiveLine over!
->Login success!
2019/07/30 17:44:09 > CWD /
2019/07/30 17:44:09 begin receiveLine...
2019/07/30 17:44:09 < 250 Directory changed to /
2019/07/30 17:44:09 receiveLine over!
2019/07/30 17:44:09 > PWD
2019/07/30 17:44:09 begin receiveLine...
2019/07/30 17:44:09 < 257 "/" is current directory.
2019/07/30 17:44:09 receiveLine over!
Current path: /
->begin upload file...
fpath:/log_b503_20190730.log
2019/07/30 17:44:09 > TYPE I
2019/07/30 17:44:09 begin receiveLine...
2019/07/30 17:44:11 < 200 Type set to I.
2019/07/30 17:44:11 receiveLine over!
2019/07/30 17:44:11 > PASV
2019/07/30 17:44:11 begin receiveLine...
2019/07/30 17:44:11 < 227 Entering Passive Mode (52,128,243,181,6,1)
2019/07/30 17:44:11 receiveLine over!
2019/07/30 17:44:11 > STOR /log_b503_20190730.log
2019/07/30 17:44:11 Connecting to 015.3vftp.com:1537
2019/07/30 17:44:11 begin receiveLine...
2019/07/30 17:44:11 < 150 Opening BINARY mode data connection for log_b503_20190730.log.
2019/07/30 17:44:11 receiveLine over!
2019/07/30 17:44:11 a1:150 Opening BINARY mode data connection for log_b503_20190730.log.
2019/07/30 17:44:11 begin receiveLine...
2019/07/30 17:44:13 < 226-Maximum disk quota limited to 102400 kBytes
2019/07/30 17:44:13 receiveLine over!
2019/07/30 17:44:13 begin receiveLine...
2019/07/30 17:44:13 <     Used disk quota 64 kBytes, available 102335 kBytes
2019/07/30 17:44:13 receiveLine over!
2019/07/30 17:44:13 begin receiveLine...
2019/07/30 17:44:13 < 226 Transfer complete.
2019/07/30 17:44:13 receiveLine over!
2019/07/30 17:44:13 a2:226-Maximum disk quota limited to 102400 kBytes
    Used disk quota 64 kBytes, available 102335 kBytes
226 Transfer complete.
->upload file over!