BMC lighttpd kvm数据分析(websocket)

1.说明

lighttpd源码: https://github.com/lighttpd/lighttpd1.4.git
lighttpd wiki: https://redmine.lighttpd.net/projects/lighttpd/wiki/
libfcgi: https://github.com/toshic/libfcgi/tree/master

注意:

本章的代码仓库: https://gitee.com/wit_yuan/lighttpd_kvm

2.编译

2.1 `lighttpd`编译与`web`访问

lighttpd编译方法，可以参考文档:https://github.com/lighttpd/lighttpd1.4/blob/master/INSTALL,命令如下:

  $ cd lighttpd-1.4.xx
  $ ./autogen.sh
  $ ./configure -C
  $ make check
  $ /usr/bin/sudo make install

安装后文件路径:

$ ls /usr/local/sbin/lighttpd* -al
-rwxr-xr-x 1 root root 2023608 8月  30 16:45 /usr/local/sbin/lighttpd
-rwxr-xr-x 1 root root   23080 8月  30 16:45 /usr/local/sbin/lighttpd-angel

配置文件lighttpd.conf，使用:https://github.com/lighttpd/lighttpd1.4/blob/master/doc/config/lighttpd.conf。配置文件:modules.conf,使用https://github.com/lighttpd/lighttpd1.4/blob/master/doc/config/modules.conf。/etc/lighttpd/conf.d/access_log.conf使用https://github.com/lighttpd/lighttpd1.4/tree/master/doc/config/conf.d。
注释掉/etc/lighttpd/lighttpd.conf:

#server.username  = "lighttpd"
#server.groupname = "lighttpd"

修改/etc/lighttpd/lighttpd.conf内容:

server.document-root = "/home/wityuan/Desktop/lighttpd/lighttpd1.4-lighttpd-1.4.76/www
server.port = 8080
server.bind = "localhost"

在目录:/home/wityuan/Desktop/lighttpd/lighttpd1.4-lighttpd-1.4.76/www中添加test.html,内容:

<!DOCTYPE html>
<html>
        <head>    
                <title> first website </title></head><body>    
                <h1> welcome
                </h1>   
                <p>this is a param.
                </p>
        </body>
</html>

执行命令：

$ sudo mkdir /var/log/lighttpd
$ sudo touch /var/log/lighttpd/error.log

启动lighttpd:

# sudo /usr/local/sbin/lighttpd -f /etc/lighttpd/lighttpd.conf

启动成功:

在这里插入图片描述

网络访问:

http://127.0.0.1:8080/test.html

在这里插入图片描述

备注：

这一篇的文件配置可以参考文档: https://redmine.lighttpd.net/projects/lighttpd/wiki/InstallFromSource

2.2 `libfcgi`下载与编译测试

从网站https://github.com/toshic/libfcgi/tree/master下载代码。

编译，使用命令:

$ ./configure
$ make
$ sudo make install

如果编译不过去，修改文件examples/Makefile.in中的内容:

echo_cpp_LDADD = $(LIBDIR)/libfcgi++.la

改为:

echo_cpp_LDADD = $(LIBDIR)/libfcgi++.la $(LIBDIR)/libfcgi.la

最后，编译生成的目录信息如下:
在这里插入图片描述

编写程序文件cgitest1.c：

#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <alloca.h>
#include <fcgiapp.h>
#define LISTENSOCK_FILENO 0
#define LISTENSOCK_FLAGS 0
int main(int argc, char** argv) {
  openlog("testfastcgi", LOG_CONS|LOG_NDELAY, LOG_USER);
  int err = FCGX_Init(); /* call before Accept in multithreaded apps */
  if (err) { syslog (LOG_INFO, "FCGX_Init failed: %d", err); return 1; }
  FCGX_Request cgi;
  err = FCGX_InitRequest(&cgi, LISTENSOCK_FILENO, LISTENSOCK_FLAGS);
  if (err) { syslog(LOG_INFO, "FCGX_InitRequest failed: %d", err); return 2; }

  while (1) {
    err = FCGX_Accept_r(&cgi);
    if (err) { syslog(LOG_INFO, "FCGX_Accept_r stopped: %d", err); break; }
    char** envp;
    int size = 200;
    for (envp = cgi.envp; *envp; ++envp) size += strlen(*envp) + 11;
    char*  result = (char*) alloca(size);
    strcpy(result, "Status: 200 OK\r\nContent-Type: text/html\r\n\r\n");
    strcat(result, "<html><head><title>testcgi</title></head><body><ul>\r\n");

    for (envp = cgi.envp; *envp; ++envp) {
      strcat(result, "<li>"); 
      strcat(result, *envp); 
      strcat(result, "</li>\r\n");
    }

    strcat(result, "</ul></body></html>\r\n");
    FCGX_PutStr(result, strlen(result), cgi.out);
  }

  return 0;
}

编译命令:

# gcc cgitest1.c -o cgitest1 -lfcgi

修改文件/etc/lighttpd/modules.conf,增加内容:

...
server.modules              += ("mod_fastcgi")
fastcgi.debug = 1
fastcgi.server += ("/cgi" =>
((
"bin-path"    => "/home/wityuan/Desktop/lighttpd/cgicode/cgitest1",
"max-procs"   => 1,
"socket"    => "/tmp/fcgi_test.socket",
"check-local" => "disable",
"allow-x-send-file" => "enable"
)))
...

注意:

1.如果运行报错:

$ /usr/local/bin/cgi-fcgi
/usr/local/bin/cgi-fcgi: error while loading shared libraries: libfcgi.so.0: cannot open shared object file: No such file or directory

可以参考:https://serverfault.com/questions/120233/how-to-configure-fastcgi-to-work-with-ligttpd-in-ubuntu

解决办法:

 export LD_LIBRARY_PATH=/usr/local/lib

2.如果运行报错:

2024-08-30 23:59:14: (gw_backend.c.676) gw-backend failed to start: /xx/cgitest1
2024-08-30 23:59:14: (gw_backend.c.678) If you're trying to run your app as a FastCGI backend, make sure you're using the FastCGI-enabled version.  If this is PHP on Gentoo, add 'fastcgi' to the USE flags.  If this is PHP, try removing the bytecode caches for now and try again.

可以执行命令:

$ sudo ldconfig

重启lighttd服务器，可以看到有2个进程:

在这里插入图片描述

访问资源，截图如下:
在这里插入图片描述

2.3 `websocket`

2.3.1 资源

websocket的资源参考如下:

js创建websocket:https://websockets.spec.whatwg.org/#the-websocket-interface
websocket api:https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API
websocket-6455官方文档:https://datatracker.ietf.org/doc/html/rfc6455

实际上，如上内容均在lighttpd中可以看到:

https://redmine.lighttpd.net/projects/lighttpd/wiki/WebSockets

2.3.2 `websocket js`与后台程序通信

这里会用到网站所说的mod_wstunnel的功能:

mod_wstunnel is a WebSocket tunnel endpoint, terminating the websocket tunnel from a client. mod_wstunnel decodes websocket frames and then passes data (without websocket frames) to a backend, and in the opposite direction encodes responses from backend into websocket frames before sending responses to client.

1.配置stunnel

在文件/etc/lighttpd/modules.conf 中新增mod_wstunnel的配置:

..,
server.modules += ("mod_wstunnel")
$HTTP["url"] =~ "^/websocket" {
  wstunnel.server = (
    "" => ((
      "host" => "127.0.0.1",
      "port" => "8081"
    ))
  )
  wstunnel.frame-type = "text"
}
...

然后编写一个后台的server程序，内容如下:

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>

// Should be same with the one in lihttpd.conf and index.html.
#define DEFAULT_PORT 8081
// Should be same with the one in lihttpd.conf.
#define DEFAULT_IP "127.0.0.1"

int main(int argc, char **argv)
{
    int server_socket = -1;
    int client_socket = -1;
    struct sockaddr_in server_addr;
    struct sockaddr_in client_addr;
    char received_buffer[1024]; // Buffer for received.
    int received_len = -1;
    int sended_len = -1;
    int res = -1;
    socklen_t addr_len = sizeof(struct sockaddr);
    int index;

    // Create a socket.
    server_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (server_socket < 0)
    {
        printf("Create socket failed: %s\n", strerror(errno));
        return -1;
    }

    // Bind the created socket on special IP and port.
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(DEFAULT_PORT);
    server_addr.sin_addr.s_addr = inet_addr(DEFAULT_IP);
    if (bind(server_socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0)
    {
        printf("Bind server failed: %s\n", strerror(errno));
        return -2;
    }
    printf("Socket[%d] has bond on port[%d] for IP address[%s]!\n",
           server_socket, DEFAULT_PORT, DEFAULT_IP);

    // Listen on the created socket.
    listen(server_socket, 10);

    while (1)
    {
        printf("Waiting and accept new client connect...\n");

        client_socket = accept(server_socket, (struct sockaddr *)&client_addr, &addr_len);
        if (client_socket < 0)
        {
            printf("Accept client socket failed: %s\n", strerror(errno));
            return -3;
        }

        printf("Accept new client[%d] socket[%s:%d]\n", client_socket,
               inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));

        while (1)
        {
            memset(received_buffer, 0, sizeof(received_buffer));

            received_len = read(client_socket, received_buffer, sizeof(received_buffer));
            if (received_len < 0)
            {
                printf("Read data from client [%d] failed: %s\n", client_socket, strerror(errno));
                close(client_socket);
                break;
            }
            else if (0 == received_len)
            {
                printf("Client [%d] disconnected!\n", client_socket);
                close(client_socket);
                break;
            }
            else
            {
                printf("Read %d bytes from client[%d] and the data is : %s\n",
                       received_len, client_socket, received_buffer);
                // Send back the received buffer to client.
                sended_len = write(client_socket, received_buffer, received_len);
                if (sended_len < 0)
                {
                    printf("wWite data back to client[%d] failed: %s \n", client_socket,
                           strerror(errno));
                    close(client_socket);
                    break;
                }
            }
        }
        sleep(1);
    }

    if (client_socket)
    {
        close(client_socket);
    }
    close(server_socket);

    return 1;
}

编译，执行程序:

# gcc server1.c -o server1
# ./server1

web端js程序命名lighttpd1.4-lighttpd-1.4.76/www/websocket.js,内容如下:

  // 获取按钮和文本框元素
  const sendBtn = document.getElementById('sendBtn');
  const messageBox = document.getElementById('messageBox');
  
  // 创建 WebSocket 对象
  const socket = new WebSocket('ws://127.0.0.1:8080/websocket'); // 使用一个 WebSocket 服务器进行测试
  
  // 设置 WebSocket 连接打开时的回调函数
  socket.onopen = function() {
     console.log('WebSocket 连接已打开');
  };
  
  // 设置 WebSocket 接收到消息时的回调函数
  socket.onmessage = function(event) {
     console.log('WebSocket 接收到消息:', event.data);
     messageBox.value += event.data + '\n';
  };
  
  // 设置 WebSocket 发生错误时的回调函数
  socket.onerror = function() {
     console.log('WebSocket 发生错误');
  };
  
  // 设置 WebSocket 连接关闭时的回调函数
  socket.onclose = function() {
     console.log('WebSocket 连接已关闭');
  };
  
  // 点击按钮时发送消息
  sendBtn.onclick = function() {
     const message = 'Hello, WebSocket!';
     socket.send(message);
     messageBox.value += '发送消息: ' + message + '\n';
  };

之后，可以看到端口被占用，服务器在监听:
在这里插入图片描述
html资源命名为lighttpd1.4-lighttpd-1.4.76/www/websocket.html，内容:

<!DOCTYPE html>
<html>
<head>
   <meta charset="UTF-8">
   <title>WebSocket 示例</title>
</head>
<body>
   <button id="sendBtn">发送消息</button>
   <textarea id="messageBox" readonly></textarea>
   <script src="websocket.js"></script>
</body>
</html>

在浏览器中访问资源:
在这里插入图片描述
服务端收到数据:

注意:

在网站: https://github.com/nori0428/mod_websocket上，有描述:DEAD.use lighttpd v1.4.46 or after w/ mod_proxy and mod_wstunnnel.，该项目已经停止维护，建议使用mod_wstunnnel了。服务器上AMI BMC的实现kvm，sol, cd-server还是在用mod_websocket。

从https://github.com/nori0428/mod_websocket/tree/master摘录一下数据流:

client <--- ssl ---> lighttpd - mod_websocket <--- tcp ---> your websocket server