/**
   * 签名实现
   */
  list($s1, $s2) = explode(' ', microtime());
  $timestamp = (float)sprintf('%.0f', (floatval($s1) + floatval($s2)) * 1000);
  $secret = '****';
  $data = $timestamp . "\n" . $secret;
  $signStr = base64_encode(hash_hmac('sha256', $data, $secret,true));
  $signStr = utf8_encode(urlencode($signStr));
  $webhook = 'https://oapi.dingtalk.com/robot/send?access_token=****';
  $webhook .= "timestamp=$timestampsign=$signStr";

  /**
   * 发送钉钉报警
   */
  $guzzleClent = new \GuzzleHttp\Client();

  $data = [
    'msgtype' => 'text',
    'text' => [
      'content' => $msg,
    ]
  ];

  $res = $guzzleClent->request('POST', $webhook,[
    'headers' => [
      'content-type' => 'application/json'
    ],
    'body' => json_encode($data),
  ]);
  $res = json_decode($res->getBody());
  var_dump($res);