Zabbix 配合 FRP 解决 zabbix-agent 无固定IP,监控困难问题

起源

由于被监控设备无公网IP, 而且处于不同的内网环境, 为解决无法远程执行命令问题, 最初阶段使用的VPN模式,每个机器运行一个 VPN 容器,容器内部网络拨号的得到 一个VPN IP
外部请求这个VPN IP, VPN 容器再将端口转发到宿主机 (转发到容器NAT网关就是转发到宿主机) ,实现内网穿透
但后来发现, 有些设备处于互联网深处的多层 NAT 网络之下,无法大部分VPN 协议都无法穿透,后面决定使用 FRP 进行内往穿透,就有了本文

思路流程

1. 在zabbix 的数据库中新建一个 frp 的数据库, 导入以下 Sql 命令

frp-3w-port.zip

1. 服务端新建一个 PHP 并开放接口, 以便 zabbix agent 请求接口获取一个随机端口, 并将端口绑定到
2. 将获取到的端口用 frp 绑定到被监控的 zabbix-agent 客户端端口 也就是zabbix agent 配置中的 ListenPort
3. 使用脚本将服务端的端口改成 frp 端口, 如下图,箭头指向的两个值都是脚本自动更新的,左边 frp 代理 zabbix-agent 端口, 右边代理 ssh 端口
4. 如果使用脚本对进行修改参考 Zabbix Api https://www.zabbix.com/documentation/5.0/zh/manual/api/reference/configuration

脚本

用于获取 frp 端口的PHP脚本

frp.php

<?php
include_once $_SERVER['DOCUMENT_ROOT'] . '/script/php/extend/frp_base.php';
class Controller
{
    public function index()
    {
        return '您好！这是一个[api]示例应用';
    }
    public function Get()
    {
        $v['obj'] = new FrpBase();
        $v['get'] = $_POST;
        $v['json'] = json_decode($v['get']['json'], true);
        $v['ret']['hostname'] = $v['json']['hostname'];
        foreach ($v['json']['port'] as $key => $value) {
            $v['ret']['port'][$value] = $v['obj']->select_service_port($v['json']['hostname'],  $value);
        }
        // print_r($v['ret']);
        echo json_encode($v['ret']);
        // $v['port'] = $v['obj']->select_service_port();
        // return json_encode($v['port']);
        // print_r($v);
    }
    function __construct()
    {
        if ($_GET['i'] == 'Get') {
            $this->Get();
        }
    }
}
$use = new Controller();
if (false) {
    $help = <<<USE
    # view-source:http://zabbix.dcache.kuaicdn.cn/script/php/controller/frp.php?i=Get&json={ "hostname": "00A01FB40CC46036-dcache", "port": ["22","12104"] }
USE;
}

frp_base.php

<?php
class Connect_mysql
{
    /* 成员变量 */
    var $info;
    var $pdo;
    function connect()
    {
        try {
            $this->pdo = new PDO(
                "mysql:host=" . $this->info["host"] . ";dbname=" . $this->info["db_name"],
                $this->info["db_user"],
                $this->info["db_pwd"]
            ); //创建一个pdo对象
            $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);  // 设置sql语句查询如果出现问题 就会抛出异常
            //set_exception_handler("cus_exception_handler");
        } catch (PDOException $e) {
            die("connect error:" . $e->getMessage());
        }
        $this->pdo->exec("set names 'utf8'");
    }
    function init()
    {
        $this->info = array(
            'host'  => 'localhost',
            'db_name'   => 'frp',
            'db_user' => 'root',
            'db_pwd' => 'passwd',
        );
    }
    function __construct()
    {
        $this->init();
        $this->connect();
    }
}
class FrpBase
{
    public $v = [];
    public $pdo;
    function __construct()
    {
        $connect_mysql = new Connect_mysql();
        $this->pdo = $connect_mysql->pdo;
    }
    function new_record($hostname, $port)
    {
        # 查询并锁行
        $v['args']['hostname'] = $hostname;
        $v['args']['port'] = $port;
        $this->pdo->beginTransaction();
        $v['sql'] = "SELECT * FROM `port` ORDER BY `port`.`time_last` ASC, `port`.`port_service` ASC limit 1 for UPDATE";
        $v['stmt'] = $this->pdo->prepare($v['sql']);
        $v['rs'] = $v['stmt']->execute();
        $v['select'] = $v['stmt']->fetch(PDO::FETCH_ASSOC);
        # 更新
        $v['stmt'] = $this->pdo->prepare("UPDATE `port` SET `time_last` = current_timestamp(), `host_sign` = :host_sign, `port_app` = :port_app WHERE `port`.`port_service` = :port_service");
        $v['stmt']->bindValue(":port_app",  $v['args']['port'], PDO::PARAM_STR);
        $v['stmt']->bindValue(":host_sign",  $v['args']['hostname'], PDO::PARAM_STR);
        $v['stmt']->bindValue(":port_service",  $v['select']['port_service'], PDO::PARAM_STR);
        $v['execute'] = $v['stmt']->execute();
        $this->pdo->commit();
        return  $v['select'];
    }
    function select_service_port($hostname, $port)
    {
        $v['args']['hostname'] = $hostname;
        $v['args']['port'] = $port;
        $v['sql'] = "SELECT * FROM `port` WHERE `port_app` = :port_app AND `host_sign` = :host_sign";
        $v['stmt'] = $this->pdo->prepare($v['sql']);
        $v['stmt']->bindValue(":port_app",  $v['args']['port'], PDO::PARAM_STR);
        $v['stmt']->bindValue(":host_sign",  $v['args']['hostname'], PDO::PARAM_STR);
        $v['execute'] = $v['stmt']->execute();
        $v['select'] = $v['stmt']->fetch(PDO::FETCH_ASSOC);
        if (!isset($v['select']['port_service'])) {
            $v['select'] = $this->new_record($v['args']['hostname'],  $v['args']['port']);
            $v['select'] = $this->select_service_port($hostname, $port);
        } else {
            $v['update'] = $this->pdo->exec("UPDATE `port` SET `time_last` = current_timestamp() WHERE `port`.`port_service` = " . $v['select']["port_service"]);
        }
        $this->dev[__METHOD__] = $v;
        return $v['select'];
    }
}