作者:

在nginx上使用php代理运行cgi程序

我们用到的很多开源程序比如mailman, nagios等等,都有WEB端管理界面。在那个Apache一家独大的年代,这个问题可以很好解决,因为apache本身可以运行cgi程序。但随着 nginx服务器的大规模应用,而恰好nginx又没有cgi模块,所以我们不得不采用一些变通的手段来解决它。

在网上广为流传的解决方法是一个老外写的perl脚本,但这个脚本本身有很多问题,而且需要在后台启动一个守护进程,本人对用perl写的网络服务守护进程的稳定性很怀疑,在看了它的代码后,发现用PHP即可很好的解决这个问题。

CGI其实本质上就是一个普通的二进制程序,你可以在后台直接运行它。而服务器要做的事就是将WEB传递的变量作为参数传递给这个程序并执行,而将执行返回的结果显示到页面上。

明白了这个道理,我们就可以开始着手解决这个问题了。其过程无非就是将PHP作为一个proxy,使其运行指定的程序,并把程序输出结果echo出来。

我们把这个PHP脚本命名为cgi.php,把它随便放到一个你认为合适的位置,然后用rewrite将后缀为cgi的请求都转发到cgi.php上。以下为参考的配置格式

#rewrite cgi请求到cgi.php上,并把cgi文件名作为php的pathinfo
rewrite ^/nagios/cgi-bin/(.*) /cgi.php/$1 break;
 
location /nagios/
{
    gzip off;
    alias /usr/local/nagios/share/;
    index index.html index.htm index.php;
}
 
location ~ .*\.php(\/.*)*$ {
    fastcgi_pass    127.0.0.1:9000;
    fastcgi_index   index.php;
    include fcgi.conf;
    fastcgi_param SCRIPT_FILENAME /usr/local/nagios/share$fastcgi_script_name;
 
    #pathinfo必须设置
    fastcgi_param  PATH_INFO $fastcgi_script_name;
 
    #以下两个为cgi.php需要用到的变量名,分别为cgi程序目录,和cgi默认index程序
    fastcgi_param  CGI_BASE  /usr/local/nagios/sbin;
    fastcgi_param  CGI_INDEX status.cgi;
}

注意上面配置文件的注释部分,在你自己设置的时候必须填上合适的值。下面就是最重要的cgi.php文件了

<?php
/*
   use php to execute mailman cgi app
   hack by 70 (magike.net@gmail.com)
   https://joyqi.com
 */
 
// get cgi base from fastcgi param
$cgi_base = '';
if (isset($_SERVER['CGI_BASE'])) {
    $cgi_base = rtrim($_SERVER['CGI_BASE'], '/') . '/';
} else {
    die('PLEASE CONFIGURE YOUR CGI_BASE PARAM');
}
 
// get pathinfo
$pathinfo = '';
if (isset($_SERVER['PATH_INFO'])) {
    $pathinfo = $_SERVER['PATH_INFO'];
} else if (isset($_SERVER['CGI_INDEX'])) {
    $pathinfo = $_SERVER['CGI_INDEX'];
} else {
    die('PLEASE CONFIGURE YOUR PATH_INFO PARAM');
}
 
// get real cgi path
$cgi_path = $cgi_base;
$cgi_file = trim($pathinfo, '/');
$cgi_file_levels = explode('/', $cgi_file);
$cgi_file_exists = false;
 
while (count($cgi_file_levels) > 0) {
    $cgi_path = $cgi_path . '/' . array_shift($cgi_file_levels);
 
    if (is_file($cgi_path)) {
        $cgi_file_exists = true;
        break;
    }
}
 
if (!$cgi_file_exists) {
    die('NOT EXISTS PAGE!' . $cgi_file);
}
 
$cgi_pathinfo = '';
if (!empty($cgi_file_levels)) {
    $cgi_pathinfo = '/' . implode('/', $cgi_file_levels);
}
 
if (is_readable($cgi_path)) {
 
    $descriptorspec = array(
            0 => array("pipe", "r"),  // stdin is a pipe that the child will read from
            1 => array("pipe", "w"),  // stdout is a pipe that the child will write to
            2 => array("file", "/tmp/error-output.txt", "a") // stderr is a file to write to
            );
 
    $cwd = $cgi_base;
    $env = $_ENV;
 
    $env['SCRIPT_FILENAME'] = $cgi_path;
    $env['SCRIPT_NAME'] = $cgi_file;
    $env['DOCUMENT_ROOT'] = CGI_BASE;
    $env['PATH_INFO'] = $cgi_pathinfo;
 
    // http auth support (nagios etc.)
    if (isset($_SERVER['PHP_AUTH_USER'])) {
        $env['REMOTE_USER'] = $_SERVER['PHP_AUTH_USER'];
    }
 
    $process = proc_open($cgi_path, $descriptorspec, $pipes, $cwd, $env);
    if (is_resource($process)) {
        $stdin = file_get_contents("php://input");
 
        if (!empty($stdin)) {
            fwrite($pipes[0], $stdin);
            fclose($pipes[0]);
        }
 
        //stream_set_blocking($pipes[1], 0);
        stream_set_timeout($pipes[1], 3);
        $result = stream_get_contents($pipes[1]);
        fclose($pipes[1]);
        $return_value = proc_close($process);
 
        list($header, $body) = preg_split("/\r?\n\r?\n/", $result, 2);
 
        $headers = explode("\n", $header);
        foreach ($headers as $line) {
            header(trim($line));
        }
 
        echo $body;
    } else {
        die('ERROR APPLICATION!');
    }
 
} else {
    die('ERROR PAGE!' . $cgi_path);
}

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