Ubuntu 18.04+OpenLiteSpeed环境下SOAP调用WebService时端口8051连接被拒问题排查求助

大家好，我目前在Ubuntu 18.04服务器上部署了OpenLiteSpeed，最近写了一段PHP代码通过SOAP调用某个Web服务，这段代码在本地测试环境完全正常，但放到生产服务器上就出问题了，想请大家帮忙排查下。

我的SOAP代码如下： #

$soapParams = array(
    'login'          => 'Name',
    'password'       => 'password',
    'authentication' => SOAP_AUTHENTICATION_BASIC,
    'trace'          => 1,
    'exceptions'     => 1,
);

$params = array();

$client = new SoapClient('https://myserver.name:8051/MEX?wsdl', $soapParams);

$params = array(
    'DataServerName' => 'NAME',
    'PrimaryKey'=>'KEYNAME',
);

$result = $client->ReadRecord($params);

echo "response:\n" . $client->__getLastResponse() . "<br><br>";

生产服务器返回的错误： #

Exceção - SOAP-ERROR: Parsing WSDL: Couldn't load from 'https://myserver.name:8051/MEX?wsdl' : failed to load external entity "https://myserver.name:8051/MEX?wsdl"

我做的排查步骤： #

1. curl测试对比：本地服务器curl该WSDL地址能正常响应，但生产服务器执行curl https://myserver.name:8051/MEX?wsdl返回：

   curl: (7) Failed to connect to myserver.name port 8051: Connection refused
   

2. 检查hosts文件：生产服务器的/etc/hosts内容如下：

   127.0.0.1       localhost servermyserver
   ::1             localhost ip6-localhost ip6-loopback
   ff02::1         ip6-allnodes
   ff02::2         ip6-allrouters
   

3. 端口监听检查：
   • 执行netstat -ln | grep 443和netstat -ln | grep 80，能看到80、443等端口正常监听（输出内容如下）：

     root@servermyserver:/etc# netstat -ln | grep 443
     tcp        0      0 0.0.0.0:443             0.0.0.0:*                           LISTEN
     tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN
     tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN
     tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN
     tcp6       0      0 :::443                  :::*                    LISTEN
     tcp6       0      0 :::443                  :::*                    LISTEN
     tcp6       0      0 :::443                  :::*                    LISTEN
     tcp6       0      0 :::443                  :::*                    LISTEN
     udp        0      0 0.0.0.0:443             0.0.0.0:*
     udp        0      0 0.0.0.0:443             0.0.0.0:*
     udp        0      0 0.0.0.0:443             0.0.0.0:*
     udp        0      0 0.0.0.0:443             0.0.0.0:*
     udp6       0      0 :::443                  :::*
     udp6       0      0 :::443                  :::*
     udp6       0      0 :::443                  :::*
     udp6       0      0 :::443                  :::*
     

     root@servermyserver:/etc# netstat -ln | grep 80
     tcp        0      0 0.0.0.0:7080            0.0.0.0:*               LISTEN
     tcp        0      0 0.0.0.0:80              0.0.0.0:*                     LISTEN
     tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN
     tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN
     tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN
     tcp        0      0 0.0.0.0:8090            0.0.0.0:*               LISTEN
     udp        0      0 0.0.0.0:7080            0.0.0.0:*
     unix  2      [ ACC ]     STREAM     LISTENING     2307434806       /usr/local/lsws/admin/tmp/admin.sock.7958
     unix  2      [ ACC ]     STREAM     LISTENING     2308072711 /tmp/lshttpd/facsu7698.sock
     

   • 但执行netstat -ln | grep 8051时没有任何输出，说明服务器根本没监听8051端口。
4. 强制IPv4测试：执行curl --ipv4 -v "https://myserver.name:8051/MEX?wsdl"，结果还是连接被拒：

   *   Trying xxx.xxx.xxx.xxx...
   * TCP_NODELAY set
   * connect to xxx.xxx.xxx.xxx port 8051 failed: Connection refused
   * Failed to connect to myserver.name:8051 port 8051: Connection refused
   * Closing connection 0
   curl: (7) Failed to connect to myserver.name:8051 port 8051: Connection refused
   

5. telnet测试：
   • 执行telnet localhost 8051返回telnet: Unable to connect to remote host: Connection refused
   • 但执行telnet localhost 80能正常连接。

现在我有点摸不着头绪了，本地环境一切正常，生产环境就是连不上8051端口，想问问大家有没有什么排查方向或者解决办法？

备注：内容来源于stack exchange，提问作者user1012130