python 实现websocket
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
3、redis
4、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 ***
也可以看看GoEasy文库的其他资料。