- 需求构思: 在linux下常常需要查看程序的实时输出,我们用 tail -f logfile 即可在console下实现此需求。现在要拓宽应用: 想在web browser下查看程序(以及日志)的实时输出(也就是程序Log的Web实时监控)。
- 架构构思: 因为考虑了“实时"这个需求,所以初步定位为socket架构; 再因为是构建在web之上,属于web app,所以socket进一步细分为:web socket。初步验证: web socket的 server部分: 可选: 1)自己实现 2) Node.js 3)其他框架(i.e. pywebsocketserver), web socket的client部分: 可选: 1) firefox 16 2) chrome 3)其他浏览器
- 架构实现
- Python里的subprocess可用pipe获取数据,再开子进程获取数据行
- Server负责把上述数据行缓存后再源源不断发送到 Client
- Client负责显示接受到的实时数据
- 代码部分
# -*- coding: utf8 -*- import sys import time import threading from pywebsocketserver.server import SocketServer from pywebsocketserver.baseio import BaseIO import subprocess def tcpdump(): global g_output_log popen=subprocess.Popen(['bash','-c',"/usr/sbin/tcpdump -i eth0 -v"],stdout=subprocess.PIPE,stderr=subprocess.PIPE) pid=popen.pid print('Popen.pid:'+str(pid)) while True: line=popen.stdout.readline().strip() #line =popen.communicate() print "output:%s" %(line) g_output_log.append(line) if subprocess.Popen.poll(popen) is not None: break print('DONE') class MyIO(BaseIO): def onData(self,uid,text): self.sendData(uid,"received the message:%s"%(text,)) def onConnect(self,uid): global g_uid g_uid=uid while True: #self.sendData(uid,"testing...") if len(g_output_log) >0: log = g_output_log.pop() self.sendData(uid,log) else: time.sleep(.01) try: g_output_log=[] g_uid=None tcpdump = threading.Thread(name='tcpdump', target=tcpdump) tcpdump.start() port = sys.argv[1] except: port = 88 port = int(port) myIo = MyIO() SocketServer(port,myIo).run()
function SocketClient(ip,port,query) { var _this = this; this.socket = ''; this.uid = 0; this.sign = ''; this.connect = function() { this.socket = new WebSocket('ws://'+ip+':'+port+'/'+query); this.socket.onopen = function() { _this.onOpen() } this.socket.onmessage = function(event) { data = event.data; data = data.split("<split>") _this.uid = data[0]; _this.sign = data[1]; text = data[2]; if(text!='SETUID') { _this.onData(text); } else { _this.onRegist() } } this.socket.onclose = function(event) { _this.onClose(); }; } this.onRegist = function() { } this.onClose = function() { } this.onOpen = function() { } this.onData = function(text) { } this.sendData = function (text) { var data = this.uid+'<split>'+this.sign+'<split>'+text this.socket.send(data); } this.close = function() { this.socket.close(); } }
<html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <script src="socketclient.js"></script> </head> <body> <script> var client = new SocketClient("192.168.199.3",88,"chat"); client.connect(); client.onData = function(text) { console.log(text); element=document.getElementById("log"); if(element){ if(element.value.length >100000) { element.value=""; } element.value += (text + "\n"); element.scrollTop = element.scrollHeight; } } client.onRegist = function() { this.sendData("I am coming!"); } </script> <textarea name="log" id="log" style="font-size:12px; width:100%; height: 600px;">Tcpdump log:</textarea> </body> </html>
- 演示说明
Server运行tcpdump,用户在浏览器查看运行的实时数据。