python製作websocket服務器實例分享

一、開始的話

使用python簡單的實現websocket服務器，可以在瀏覽器上實時顯示遠程服務器的日誌信息。

之前做了一個web版的發佈系統，但沒實現在線看日誌，每次發佈版本後，都需要登錄到服務器上查看日誌，非常麻煩，爲了偷懶，能在頁面點幾下按鈕完成工作，這幾天查找了這方面的資料，實現了這個功能，瞬間覺的看日誌什麼的，太方便了，以後也可以給開發們查日誌，再也不用麻煩運維了，廢話少說，先看效果吧。

二、代碼

需求：在web上彈出iframe層來實時顯示遠程服務器的日誌，點擊stop按鈕，停止日誌輸出，以便查看相關日誌，點start按鈕，繼續輸出日誌，點close按鈕，關閉iframe層。

在實現這功能前，google了一些資料，發現很多只能在web上顯示本地的日誌，不能看遠程服務器的日誌，能看遠程日誌的是引用了其他框架（例如bottle，tornado）來實現的，而且所有這些都是要重寫thread的run方法來實現的，由於本人技術太菜，不知道怎麼改成自己需要的樣子，而且我是用django這個web框架的，不想引入其他框架，搞的太複雜，所以用python簡單的實現websocket服務器。recv_data方法和send_data是直接引用別人的代碼。由於技術問題，代碼有點粗糙，不過能實現功能就行，先將就着用吧。

執行下面命令啓動django和websocketserver

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

　　啓動websocket後，接收到請求，起一個線程和客戶端握手，然後根據客戶端發送的ip和type，去數據庫查找對應的日誌路徑，用paramiko模塊ssh登錄到遠程服務器上tail查看日誌，再推送給瀏覽器，服務端完整代碼如下：
# 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): # 服務器解析瀏覽器發送的信息
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): # 服務器處理髮送給瀏覽器的信息
if data:
    data = str(data)
else:
    return False
token = "\x81"
length = len(data)
if length < 126:
    token += struct.pack("B", length) # struct爲Python中處理二進制數的模塊，二進制流爲C，或網絡流的形式。
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)            # 設置socket爲非阻塞

ssh = get_ssh('192.168.1.1', 'root', '123456') # 連接遠程服務器
ssh_t = ssh.get_transport()
chan = ssh_t.open_session()
chan.setblocking(0) # 設置非阻塞
chan.exec_command('tail -f /var/log/messages')

while True:
    clientdata = recv_data(conn)
    if clientdata is not None and 'quit' in clientdata: # 但瀏覽器點擊stop按鈕或close按鈕時，斷開連接
      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() # 接收日誌信息
        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的代碼如下：

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"

打開頁面時，自動連接websocket服務器，完成握手，併發送ip和type給服務端，所以可以看不同類型，不同機器上的日誌，

頁面代碼如下:

<!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"); //日誌過多時清屏
          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; //滾動條顯示最新數據
    }
    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); //先得到當前iframe層的索引
      parent.layer.close(index); //再執行關閉
    }
</script>

</head>

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

</html>

以上就是本文的全部內容了，希望大家能夠喜歡