python 中 websocket 需要我们自己实现握手代码, 流程是这样: 服务端启动 websocket 服务, 并监听. 当客户端连接过来时,(需要我们自己实现) 服务端就接收客户端的请求数据, 拿到请求头, 根据请求头信息封装响应头, 并将响应头发给前端, 这样就完成了一次握手, 接下来服务端和客户端才可以通信.
上代码, 我的代码只涉及到服务端发消息给客户端的情况
先说一下代码涉及到的知识
1, 单例模式
2, 多线程
- ,Redis
- ,websokcet
5, 在 docker 容器中运行
- #!/usr/bin python
- # -*- coding:UTF-8 -*-
- import Redis
- import time, threading, sched, JSON, socket, base64, hashlib,logging,traceback
- allkv_json = "" # 发送给前端的数据
- conn_list = [] # 处于在线的 socket 链接
- # 单例
- def singleton(cls):
- instances = {}
- def getinstatce(*args, **kwargs):
- if cls not in instances:
- instances[cls] = cls(*args, **kwargs)
- return instances[cls]
- return getinstatce
- @singleton
- class RedisUtils:
- def __init__(self, port, db):
- self.redis_object = Redis.Redis('127.0.0.1', port, db)
- self.allKV = []
- def get_all_kv(self):
- keys = self.redis_object.keys()
- self.allKV = [key for key in keys if self.redis_object.ttl(key) is not None]
- # for key in keys:
- # self.allKV[key] = 'online' if (time.time() - int(self.redis_object.get(key))) <10 else 'off_line'
- class SchedTask:
- allkv = []
- @classmethod
- def getHostOnlineStatus(cls):
- global allkv_json
- ru = RedisUtils(6379, 1)
- ru.get_all_kv()
- cls.allkv = ru.allKV
- allkv_json = JSON.dumps(cls.allkv)
- print allkv_json
- @classmethod
- def getHostOnlineStatusTask(cls):
- threading.Thread(target=cls.getHostOnlineStatus).start()
- @classmethod
- def run(cls, timedelay):
- while True:
- s = sched.scheduler(time.time, time.sleep)
- s.enter(timedelay, 1, cls.getHostOnlineStatusTask, ())
- s.run()
- class WebsocketUtils(threading.Thread):
- 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-Location: ws://{2}/chat\r\n" "WebSocket-Protocol:chat\r\n\r\n"
- def __init__(self, host, port):
- if not isinstance(host, str):
- raise KeyError("The host must be a string like \'127.0.0.1\'")
- else:
- self.host = host
- if not isinstance(port, int):
- raise KeyError('The port must be a integer')
- else:
- self.port = port
- try:
- self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
- self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
- self.sock.bind((host, port))
- print '========================================================================================='
- print host,port
- self.sock.listen(100)
- except:
- print traceback.format_exc()
- print 'start socket error'
- super(WebsocketUtils, self).__init__()
- # 前端握手
- def handshake(self, conn):
- headers = {}
- shake = conn.recv(1024)
- print shake
- if not len(shake):
- print('len error')
- return False
- 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('this is not websocket, client close.')
- print headers
- conn.close()
- return False
- sec_key = headers['Sec-WebSocket-Key']
- res_key = base64.b64encode(hashlib.sha1(sec_key + WebsocketUtils.MAGIC_STRING).digest())
- str_handshke = WebsocketUtils.HANDSHAKE_STRING.replace('{1}', res_key).replace('{2}',
- self.host + ":" + str(self.port))
- print str_handshke
- conn.send(str_handshke)
- i=0
- def send_msg(self):
- WebsocketUtils.i+=1
- global conn_list
- print 'send msg' +str(WebsocketUtils.i)
- for conn in conn_list:
- try:
- conn.send('%c%c%s' % (0x81, len(allkv_json), allkv_json))
- except:
- print 'send msg error'
- conn.close()
- conn_list.remove(conn)
- # 定时给前端发信息
- def sched_send_msg(self):
- while True:
- s=sched.scheduler(time.time,time.sleep)
- s.enter(2,1,self.send_msg,())
- s.run()
- def run(self):
- # 另开一个线程给各个 conn 发消息
- global conn_list
- t=threading.Thread(target=self.sched_send_msg)
- t.start()
- while True:
- print 'wait link'
- try:
- print self.sock
- self.conn, addr = self.sock.accept()
- print 'link ok'
- self.handshake(self.conn)
- print 'handshake ok'
- conn_list.append(self.conn)
- except:
- print traceback.format_exc()
- print 'error'
- time.sleep(3)
- if __name__ == '__main__':
- # websocket 线程
- websocket_utils = WebsocketUtils('0.0.0.0', 9000)
- #websocket_utils.setDaemon(True) # 把当前进程设置为守护进程, 主线程执行完毕, 子线程均停止
- websocket_utils.start()
- # 定时获取主机在线信息
- SchedTask.run(5)
上 JS 代码
- <html> <head>
- <script type="text/JavaScript">
- var socket = new WebSocket('ws://192.168.81:9000');
- console.log('socket :' + socket);
- socket.onopen = function(e)
- {
- console.log('onopen :' + e);
- var element = document.getElementById("holder");
- element.innerHTML += 'onopen :'
- element.innerHTML += e;
- element.innerHTML += "<br>";
- }
- socket.onclose = function(e)
- {
- console.log('onclose :' + e + '; length :' + arguments.length);
- var element = document.getElementById("holder");
- element.innerHTML += 'close :'
- element.innerHTML += e;
- element.innerHTML += "<br>";
- }
- socket.onmessage = function(e)
- {
- console.log('onmessage :' + e + '; length :' + arguments.length);
- console.log('data :' + e.data);
- socket.send('chengang');
- var element = document.getElementById("holder");
- element.innerHTML += 'onmessage :'
- element.innerHTML += e
- element.innerHTML += "<br>";
- element.innerHTML += 'data :'
- element.innerHTML += e.data;
- element.innerHTML += "<br>";
- }
- </script>
- </head> <body>
- <div id="holder" style="width:600px; height:300px"></div>
- </body> </HTML>
因为是在 docket 容器中运行的服务端, 所以需要在端口映射 9000:9000 客户端 JS 代码的 ip 必须是服务端宿主机的 ip
可能用的命令, 可能会涉及到防火墙的关闭和查看端口是否开放可以这样做
查看 CentOS 端口是否开放 在 windos 中 telnet 192.168.82.2 80 可以知道 192.168.82.2 这个主机的 80 端口是否开放, 需要打开 Windows 中 telnet 在所有程序中打开, 自行百度
查看 CentOS 端口占用 netstat -nap |grep ***
来源: http://www.bubuko.com/infodetail-2785412.html