python制作websocket服务器实例分享

一、开始的话

　　使用python简单的实现websocket服务器，可以在浏览器上实时显示远程服务器的日志信息。

　　之前做了一个web版的发布系统，但没实现在线看日志，每次发布版本后，都需要登录到服务器上查看日志，非常麻烦，为了偷懒，能在页面点几下按钮完成工作，这几天查找了这方面的资料，实现了这个功能，瞬间觉的看日志什么的，太方便了，以后也可以给开发们查日志，再也不用麻烦运维了，废话少说，先看效果吧。

二、代码

　　需求：在web上弹出iframe层来实时显示远程服务器的日志，点击stop按钮，停止日志输出，以便查看相关日志，点start按钮，继续输出日志，点close按钮，关闭iframe层。

　　在实现这功能前，google了一些资料，发现很多只能在web上显示本地的日志，不能看远程服务器的日志，能看远程日志的是引用了其他框架（例如bottle，tornado）来实现的，而且所有这些都是要重写thread的run方法来实现的，由于本人技术太菜，不知道怎么改成自己需要的样子，而且我是用django这个web框架的，不想引入其他框架，搞的太复杂，所以用python简单的实现websocket服务器。recv_data方法和send_data是直接引用别人的代码。由于技术问题，代码有点粗糙，不过能实现功能就行，先将就着用吧。

执行下面命令启动django和websocketserver

    nohup python manage.py runserver 10.1.12.110 &
    nohup python websocketserver.py &

　　启动websocket后，接收到请求，起一个线程和客户端握手，然后根据客户端发送的ip和type，去数据库查找对应的日志路径，用paramiko模块ssh登录到远程服务器上tail查看日志，再推送给浏览器，服务端完整代码如下：

    # coding:utf-8
    import os
    import struct
    import base64
    import hashlib
    import socket
    import threading
    import paramiko


    def get_ssh(ip, user, pwd):
      try:
        ssh = paramiko.SSHClient()
        ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        ssh.connect(ip, 22, user, pwd, timeout=15)
        return ssh
      except Exception, e:
        print e
        return "False"


    def recv_data(conn):  # 服务器解析浏览器发送的信息
      try:
        all_data = conn.recv(1024)
        if not len(all_data):
          return False
      except:
        pass
      else:
        code_len = ord(all_data[1]) & 127
        if code_len == 126:
          masks = all_data[4:8]
          data = all_data[8:]
        elif code_len == 127:
          masks = all_data[10:14]
          data = all_data[14:]
        else:
          masks = all_data[2:6]
          data = all_data[6:]
        raw_str = ""
        i = 0
        for d in data:
          raw_str += chr(ord(d) ^ ord(masks[i % 4]))
          i += 1
        return raw_str


    def send_data(conn, data):  # 服务器处理发送给浏览器的信息
      if data:
        data = str(data)
      else:
        return False
      token = "\x81"
      length = len(data)
      if length < 126:
        token += struct.pack("B", length)  # struct为Python中处理二进制数的模块，二进制流为C，或网络流的形式。
      elif length <= 0xFFFF:
        token += struct.pack("!BH", 126, length)
      else:
        token += struct.pack("!BQ", 127, length)
      data = '%s%s' % (token, data)
      conn.send(data)
      return True


    def handshake(conn, address, thread_name):
      headers = {}
      shake = conn.recv(1024)
      if not len(shake):
        return False

      print ('%s : Socket start handshaken with %s:%s' % (thread_name, address[0], address[1]))
      header, data = shake.split('\r\n\r\n', 1)
      for line in header.split('\r\n')[1:]:
        key, value = line.split(': ', 1)
        headers[key] = value

      if 'Sec-WebSocket-Key' not in headers:
        print ('%s : This socket is not websocket, client close.' % thread_name)
        conn.close()
        return False

      MAGIC_STRING = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
      HANDSHAKE_STRING = "HTTP/1.1 101 Switching Protocols\r\n" \
                "Upgrade:websocket\r\n" \
                "Connection: Upgrade\r\n" \
                "Sec-WebSocket-Accept: {1}\r\n" \
                "WebSocket-Origin: {2}\r\n" \
                "WebSocket-Location: ws://{3}/\r\n\r\n"

      sec_key = headers['Sec-WebSocket-Key']
      res_key = base64.b64encode(hashlib.sha1(sec_key + MAGIC_STRING).digest())
      str_handshake = HANDSHAKE_STRING.replace('{1}', res_key).replace('{2}', headers['Origin']).replace('{3}', headers['Host'])
      conn.send(str_handshake)
      print ('%s : Socket handshaken with %s:%s success' % (thread_name, address[0], address[1]))
      print 'Start transmitting data...'
      print '- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -'
      return True


    def dojob(conn, address, thread_name):
      handshake(conn, address, thread_name)   # 握手
      conn.setblocking(0)            # 设置socket为非阻塞

      ssh = get_ssh('192.168.1.1', 'root', '123456')  # 连接远程服务器
      ssh_t = ssh.get_transport()
      chan = ssh_t.open_session()
      chan.setblocking(0)  # 设置非阻塞
      chan.exec_command('tail -f /var/log/messages')

      while True:
        clientdata = recv_data(conn)
        if clientdata is not None and 'quit' in clientdata:  # 但浏览器点击stop按钮或close按钮时，断开连接
          print ('%s : Socket close with %s:%s' % (thread_name, address[0], address[1]))
          send_data(conn, 'close connect')
          conn.close()
          break
        while True:
          while chan.recv_ready():
            clientdata1 = recv_data(conn)
            if clientdata1 is not None and 'quit' in clientdata1:
              print ('%s : Socket close with %s:%s' % (thread_name, address[0], address[1]))
              send_data(conn, 'close connect')
              conn.close()
              break
            log_msg = chan.recv(10000).strip()  # 接收日志信息
            print log_msg
            send_data(conn, log_msg)
          if chan.exit_status_ready():
            break
          clientdata2 = recv_data(conn)
          if clientdata2 is not None and 'quit' in clientdata2:
            print ('%s : Socket close with %s:%s' % (thread_name, address[0], address[1]))
            send_data(conn, 'close connect')
            conn.close()
            break
        break


    def ws_service():

      index = 1
      sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
      sock.bind(("127.0.0.1", 12345))
      sock.listen(100)

      print ('\r\n\r\nWebsocket server start, wait for connect!')
      print '- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -'
      while True:
        connection, address = sock.accept()
        thread_name = 'thread_%s' % index
        print ('%s : Connection from %s:%s' % (thread_name, address[0], address[1]))
        t = threading.Thread(target=dojob, args=(connection, address, thread_name))
        t.start()
        index += 1


    ws_service()

get_ssh的代码如下：

import paramiko
def get_ssh(ip, user, pwd):
  try:
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    ssh.connect(ip, 22, user, pwd, timeout=15)
    return ssh
  except Exception, e:
    print e
    return "False"

打开页面时，自动连接websocket服务器，完成握手，并发送ip和type给服务端，所以可以看不同类型，不同机器上的日志，

页面代码如下:

<!DOCTYPE html>  
<html>  
<head>  
  <title>WebSocket</title>  

  <style>  
  #log {  
    width: 440px;  
    height: 200px;  
    border: 1px solid #7F9DB9;  
    overflow: auto;  
  }  
  pre {  
    margin: 0 0 0;  
    padding: 0;  
    border: hidden;  
    background-color: #0c0c0c;  
    color: #00ff00;  
  }  
  #btns {  
    text-align: right;  
  }  
  </style>  

  <script>  
    var socket;  
    function init() {  
      var host = "ws://127.0.0.1:12345/";  

      try {  
        socket = new WebSocket(host);  
        socket.onopen = function () {  
          log('Connected');  
        };  
        socket.onmessage = function (msg) {  
          log(msg.data);  
          var obje = document.getElementById("log");  //日志过多时清屏  
          var textlength = obje.scrollHeight;  
          if (textlength > 10000) {  
            obje.innerHTML = '';  
          }  
        };  
        socket.onclose = function () {  
          log("Lose Connection!");  
          $("#start").attr('disabled', false);  
          $("#stop").attr('disabled', true);  
        };  
        $("#start").attr('disabled', true);  
        $("#stop").attr('disabled', false);  
      }  
      catch (ex) {  
        log(ex);  
      }  
    }  
    window.onbeforeunload = function () {  
      try {  
        socket.send('quit');  
        socket.close();  
        socket = null;  
      }  
      catch (ex) {  
        log(ex);  
      }  
    };  
    function log(msg) {  
      var obje = document.getElementById("log");  
      obje.innerHTML += '<pre><code>' + msg + '</code></pre>';  
      obje.scrollTop = obje.scrollHeight;  //滚动条显示最新数据  
    }  
    function stop() {  
      try {  
        log('Close connection!');  
        socket.send('quit');  
        socket.close();  
        socket = null;  
        $("#start").attr('disabled', false);  
        $("#stop").attr('disabled', true);  
      }  
      catch (ex) {  
        log(ex);  
      }  
    }  
    function closelayer() {  
      try {  
        log('Close connection!');  
        socket.send('quit');  
        socket.close();  
        socket = null;  
      }  
      catch (ex) {  
        log(ex);  
      }  
      var index = parent.layer.getFrameIndex(window.name); //先得到当前iframe层的索引  
      parent.layer.close(index); //再执行关闭  
    }  
  </script>  

</head>  


<body onload="init()">  
  <div >  
    <div >  
      <div id="log" ></div>  
      <br>  
    </div>  
  </div>  
  <div >  
    <div >  
      <div id="btns">  
        <input disabled="disabled" type="button" value="start" id="start" onclick="init()">  
        <input disabled="disabled" type="button" value="stop" id="stop" onclick="stop()" >  
        <input type="button" value="close" id="close" onclick="closelayer()" >  
      </div>  
    </div>  
  </div>  
</body>  

</html>

以上就是本文的全部内容了，希望大家能够喜欢