websocket协议学习
Talk is cheap.先看实例：
wget http://openresty.org/download/ngx_openresty-1.5.8.1.tar.gz
tar xzvf ngx_openresty-1.5.8.1.tar.gz
cd ngx_openresty-1.5.8.1
./configure --with-luajitwebsocket.html
<html>
<head>
<script>
var ws = null;
function connect() {
if (ws !== null) return log('already connected');
ws = new WebSocket('ws://192.168.65.138/s');
ws.onopen = function() {
log('connected');
};
ws.onerror = function(error) {
log('error:' + error);
};
ws.onmessage = function(e) {
log('recv: ' + e.data);
};
ws.onclose = function() {
log('disconnected');
ws = null;
};
return false;
}
function disconnect() {
if (ws === null) return log('already disconnected');
ws.close();
return false;
}
function send() {
if (ws === null) return log('please connect first');
var text = document.getElementById('text').value;
document.getElementById('text').value = "";
log('send: ' + text);
ws.send(text);
return false;
}
function log(text) {
var li = document.createElement('li');
li.appendChild(document.createTextNode(text));
document.getElementById('log').appendChild(li);
return false;
}
</script>
</head>
<body>
<form onsubmit="return send();">
<button type="button" onclick="return connect();">
Connect
</button>
<button type="button" onclick="return disconnect();">
Disconnect
</button>
<input id="text" type="text">
<button type="submit">
Send
</button>
</form>
<ol id="log">
</ol>
</body>
</html>nginx.conf
#user nobody;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
error_log logs/error.log info;
#pid logs/nginx.pid;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
lua_package_path "/root/github/nginx-study/openrestry/lualib/resty/websocket/?.lua;;";
gzip on;
gzip_min_length 1;
server {
listen 80 so_keepalive=2s:2s:8;
location /s {
lua_socket_log_errors on;
lua_check_client_abort on;
content_by_lua '
local server = require "resty.websocket.server"
local wb, err = server:new{
timeout = 50000,
max_payload_len = 65535,
}
if not wb then
ngx.log(ngx.ERR, "failed to new websocket: ", err)
return ngx.exit(444)
end
while true do
local data, typ, err = wb:recv_frame()
if wb.fatal then
ngx.log(ngx.ERR, "failed to receive frame: ", err)
return ngx.exit(444)
end
if not data then
local bytes, err = wb:send_ping()
if not bytes then
ngx.log(ngx.ERR, "failed to send ping: ", err)
return ngx.exit(444)
end
elseif typ == "close" then break
elseif typ == "ping" then
local bytes, err = wb:send_pong()
if not bytes then
ngx.log(ngx.ERR, "failed to send pong: ", err)
return ngx.exit(444)
end
elseif typ == "pong" then
ngx.log(ngx.INFO, "client ponged")
elseif typ == "text" then
local bytes, err = wb:send_text(data)
if not bytes then
ngx.log(ngx.ERR, "failed to send text: ", err)
return ngx.exit(444)
end
end
end
wb:send_close()
';
}
}
}既然是websocket协议，那么就需要从http协议转化为websocket协议
GET http://192.168.65.138/s HTTP/1.1
Origin: http://192.168.65.138
Sec-WebSocket-Key: D0QLjvO4fnHcXaE0/gqn6A==
Connection: Upgrade
Upgrade: Websocket
Sec-WebSocket-Version: 13
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko
Host: 192.168.65.138
DNT: 1
Cache-Control: no-cacheHTTP/1.1 101 Switching Protocols
Server: openresty/1.5.8.1
Date: Thu, 10 Apr 2014 06:52:07 GMT
Connection: upgrade
Upgrade: websocket
Sec-WebSocket-Accept: OedKikXLqz4gzGARLjmhZzRcNjk=具体实现可以看春哥的lua-resty-websocket，实际上就是lua通过ngx.req.socket接管http处理的socket，然后在此socket上实现websocket协议。剩余的都是协议RFC6455的实现。
嘎嘎嘎，这里得瑟下，我给春哥提了个bug。虽然是个简单的bug，但是嘎嘎嘎嘎，现在的我迫切需要得到别人的肯定。