go并发实现批量获取主机日志到本地

package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"os/exec"
	"strings"
	"sync"
	"time"
)

/*  并发实现 本地远程获取多个主机/var/log/messages.log 备份到本地目录以ip+端口命名。

实现步骤
1.准备ssh host文件  ip 用户名 端口（互为免密）1个物理机起了两个docker 不同ssh端口，所以备份到本地日志名格式为ip—端口-时间）
root,192.168.8.105,2020
root,192.168.8.105,2021
2.输入一条命令测试远程插入message.log文件是否正常  //获取当前时间 拼接备份文件名
3.远程备份messages.log文件 ip+端口+messages.log+时间格式文件（
4.copy远程文件到本地目录 每次覆盖之前的日志文件，然后删除远程备份文件log日志


*/
func Logtime() string {
	now := time.Now()
	time_fmt := "2006-01-02-15-04-05"
	ts := now.Format(time_fmt)
	return ts

}

func ReadHost() []string {
	fin, err := os.Open("hosts.txt")
	if err != nil {
		fmt.Printf("打开文件失败:%v\n", err)
	}
	defer fin.Close()
	reder := bufio.NewReader(fin)
	Hostslice := []string{}
	for {
		line, err := reder.ReadString('\n')
		if err != nil {
			if err == io.EOF {
				break
			} else {
				fmt.Printf("读文件失败:%v\n", err)
			}
		} else {
			line = strings.TrimRight(line, "\n")

			/*str 切割获取3位
			str := strings.Split(line, ",")
			if len(str) == 3 {
				a,b,c = str[0],str[1],str[2]
			}
			*/
			Hostslice = append(Hostslice, line)

		}
	}
	return Hostslice
}

var wg = sync.WaitGroup{}

func SSH_CMD(hostlist []string) {
	P := len(hostlist)
	wg.Add(P)
	fmt.Println(len(hostlist), hostlist)

	for i := 1; i < len(hostlist); i++ {
		for _, v := range hostlist {
			//并发
			go func(v string) {
				defer wg.Done()
				host_msg := strings.Split(v, ",")
				host_port := host_msg[2]
				user_ip := host_msg[0] + "@" + host_msg[1]
				//command指令
				command_log := "cat /var/log/message.log"
				insert_msg := "echo 'insert hello 01'>> /var/log/message.log"

				//插入远程主机一条信息
				insert_msg_command := exec.Command("ssh", user_ip, "-p", host_port, insert_msg)
				insert_msg_command.Run()

				//查看远程主机message.log日志
				cmd := exec.Command("ssh", user_ip, "-p", host_port, command_log)
				output, err := cmd.Output()
				if err != nil {
					fmt.Printf("发生错误%s", err)
				} else {
					fmt.Printf("%s", output)
					cmd.Run()
				}

				//生成时间格式文件备份message.log 格式为 message.log-2022-09-18-15:37:46
				ts := Logtime()
				Messages_Time_Name := "/var/log/" + host_msg[1] + "-message.log-" + ts
				fmt.Println(Messages_Time_Name, "copy阶段")

				bak_message_name := "cp /var/log/message.log " + Messages_Time_Name
				bak_message_command := exec.Command("ssh", user_ip, "-p", host_port, bak_message_name)
				fmt.Println(bak_message_command)
				bak_message_command.Run()

				//scp 远程主机文件到本地
				//scp -rp -P 22  /var/log/message.log  mzk@192.168.8.105:/Users/mzk/
				//推模式 远程主机目录推到本地
				// remote_to_localhost := "scp -rp -P 22  /var/log/message.log  mzk@192.168.8.105:/Users/mzk/host_message/"
				remote_to_localhost := "scp -rp -P 22  " + Messages_Time_Name + " " + "mzk@192.168.8.105:/Users/mzk/host_message/" + host_msg[1] + "-" + host_port + " " + "&& rm -rf " + Messages_Time_Name + ""

				//执行命令/usr/bin/ssh root@192.168.8.105 -p 2020 scp -rp -P 22  /var/log/192.168.8.105-message.log-2022-09-18-16-13-23 mzk@192.168.8.105:/Users/mzk/host_message/192.168.8.105 && rm -rf /var/log/192.168.8.105-message.log-2022-09-18-16-13-23
				scp_command := exec.Command("ssh", user_ip, "-p", host_port, remote_to_localhost)
				fmt.Println(scp_command)
				scpoutput, err := scp_command.Output()
				if err != nil {
					fmt.Printf("\n>>>>>>%s----发生错误%s\n", host_msg[1], err)
				} else {
					fmt.Printf("%s", scpoutput)
					scp_command.Run()
				}
			}(v) //并发需要copy把值传进来（[root,192.168.8.105,2020],[root,192.168.8.105,2021]）2个线程

		}
	}
	wg.Wait()
}

func main() {
	hostlist := ReadHost()
	SSH_CMD(hostlist)

	/*  如果main线程提前终止 其他线程没有执行完，会导致整个程序退出
	var wg = sync.WaitGroup{}
	const P = 2
	wg.Add(P) //初始值为1
	go func() {
		defer wg.Done()
		SSH_CMD(hostlist) //do something
	}()
	wg.Wait()
	*/

	// time.Sleep(5 * time.Second)
}