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-8import osimport structimport base64import hashlibimport socketimport threadingimport paramikodef 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_strdef 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 Truedef 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 Truedef 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 breakdef 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 += 1ws_service()

get_ssh的代码如下：

import paramikodef 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