「IM系列」WebSocket教程：跨语言 WebSocketd 让实时通信更简单！

WebSocketd 是WebSocket的守护进程（命令行工具），负责处理WebSocket连接，并启动服务器应用程序来处理WebSockets，在应用程序和Web浏览器之间传递消息，无需任意依赖包且进程独立。WebSocketd是一款非常特别的WebSocket服务器，它的最大特点是后台脚本不限语言，其标准输入stdin就是WebSocket的输入，标准输出stdout就是WebSocket的输出。

安装

代码语言：javascript

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// 下载 wget https://github.com/joewalnes/websocketd/releases/download/v0.4.1/websocketd-0.4.1-linux_amd64.zip

// 解压 unzip websocketd-v0.4.1-linux_amd64.zip

解压后生成这个文件：websocketd

输入help查看看是否配置合适，如下所示：

代码语言：javascript

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./websocketd -version

websocketd 0.4.1 (go1.15.7 linux-amd64)

简单示例

shell脚本

计数器 counter.sh

代码语言：javascript

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#!/bin/bash

for ((COUNT = 1; COUNT <= 10; COUNT++)); do

echo $COUNT

sleep 1

done

启动websocketd

代码语言：javascript

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chmod 777 counter.sh

/var/www/websocketd/websocketd --port=8888 /var/www/websocketd/counter.sh

上面的命令会启动一个 WebSocket 服务器，端口是8888。每当客户端连接这个服务器，就会执行counter.sh脚本，并将它的输出推送给客户端。

预览

控制台

代码语言：javascript

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var ws = new WebSocket('ws://127.0.0.1/');

ws.onopen = function() {

console.log('CONNECT');

};

ws.onclose = function() {

console.log('DISCONNECT');

ws.close();

};

ws.onmessage = function(event) {

console.log('MESSAGE: ' + event.data);

};

HTML文件

代码语言：javascript

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<!doctype html>

<html lang="">

<head>

<meta charset="utf-8">

<meta name="description" content="">

<meta name="viewport" content="width=device-width, initial-scale=1">

<meta http-equiv="x-ua-compatible" content="ie=edge">

<title>开源技术小栈</title>

</head>

<body>

<h2>websocketd 客户端测试</h2>

<pre id="message" style="font-size: 24px;"></pre>

<script>

function log(msg) {

document.getElementById('message').textContent += msg + '\n';

}
var ws = new WebSocket(&#39;ws://127.0.0.1:8888/&#39;);
ws.onopen = function() {
    console.log(&#39;CONNECT&#39;);
};
ws.onclose = function() {
    console.log(&#39;DISCONNECT&#39;);
    ws.close();
};
ws.onmessage = function(event) {
    console.log(&#39;MESSAGE: &#39; + event.data);
    log(&#39;websocketd服务端响应：&#39;+event.data);
};

</script>

</body>

</html>

服务端打印日志

代码语言：javascript

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/var/www/websocketd # /var/www/websocketd/websocketd --port=8888 /var/www/websocketd/counter.sh

Sun, 24 Dec 2023 10:54:15 +0800 | INFO   | server     |  | Serving using application   : /var/www/websocketd/counter.sh

Sun, 24 Dec 2023 10:54:15 +0800 | INFO   | server     |  | Starting WebSocket server   : ws://4bc07756b82c/

Sun, 24 Dec 2023 10:54:32 +0800 | ACCESS | session    | url:'http://127.0.0.1/' id:'1703386472745570850' remote:'172.18.0.1' command:'/var/www/websocketd/counter.sh' origin:'file:' | CONNECT

Sun, 24 Dec 2023 10:54:42 +0800 | ACCESS | session    | url:'http://127.0.0.1/' id:'1703386472745570850' remote:'172.18.0.1' command:'/var/www/websocketd/counter.sh' origin:'file:' pid:'316' | DISCONNECT

实时监控内存信息

shell脚本

系统内存脚本 system_info.sh

代码语言：javascript

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#!/bin/bash

PATH=/usr/local/bin:/usr/bin:/bin
SHELL_DIR="/var/www/websocketd"

SHELL_NAME="system_info"

SHELL_TIME=$(date '+%Y-%m-%d')

SHELL_LOG="{SHELL_DIR}/{SHELL_NAME}-${SHELL_TIME}.log"
REDIS_MEMORY_KEYS_NAME="REDIS_MEMORY_INFO:001"

REDIS_DISH_KEYS_NAME="REDIS_DISH_INFO:001"
while(true)

do

FIND_DATA=$(cat /proc/meminfo | grep "MemFree:" | awk '{print $2}')

echo  "[SHELL_TIME]: FIND_DATA = FIND_DATA INSERT_RES = {INSERT_RES} CUT_LIST_LEN = {CUT_LIST_LEN}" >> $SHELL_LOG

echo   '{"data":'"${FIND_DATA}"',"errcode":0,"errmsg":0}'

sleep 2

done

启动websocketd

代码语言：javascript

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chmod 777 counter.sh

/var/www/websocketd/websocketd --port=8888 /var/www/websocketd/counter.sh

HTML页面

代码语言：javascript

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<!doctype html>

<html lang="">

<head>

<meta charset="utf-8">

<meta name="description" content="">

<meta name="viewport" content="width=device-width, initial-scale=1">

<meta http-equiv="x-ua-compatible" content="ie=edge">

<title>开源技术小栈</title>

</head>

<body>

<h2>websocketd 客户端测试</h2>

<pre id="message" style="font-size: 24px;"></pre>

<script>

function log(msg) {

document.getElementById('message').textContent += msg + '\n';

}
var ws = new WebSocket(&#39;ws://127.0.0.1:8888/&#39;);
ws.onopen = function() {
    console.log(&#39;CONNECT&#39;);
};
ws.onclose = function() {
    console.log(&#39;DISCONNECT&#39;);
    ws.close();
};
ws.onmessage = function(event) {
    console.log(&#39;MESSAGE: &#39; + event.data);
    log(&#39;websocketd服务端响应：&#39;+event.data);
};

</script>

</body>

</html>

运行效果

参数配置

--staticdir=

--staticdir= 允许websocketd作为静态文件提供counter.html

count.sh 文件

代码语言：javascript

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#!/bin/bash

for COUNT in $(seq 1 10); do

echo $COUNT

sleep 1

done

count.html 文件

代码语言：javascript

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<!DOCTYPE html>

<html>

<head>

<title>websocketd count example</title>

<style>

#count {

font: bold 150px arial;

margin: auto;

padding: 10px;

text-align: center;

}

</style>

</head>

<body>
&lt;div id=&#34;count&#34;&gt;&lt;/div&gt;

&lt;script&gt;
  var ws = new WebSocket(&#39;ws://127.0.0.1:8888/&#39;);
  ws.onopen = function() {
    document.body.style.backgroundColor = &#39;#cfc&#39;;
  };
  ws.onclose = function() {
    document.body.style.backgroundColor = null;
  };
  ws.onmessage = function(event) {
    document.getElementById(&#39;count&#39;).textContent = event.data;
  };
&lt;/script&gt;

</body>

</html>

运行websocketd。注意参数--staticdir=. ./count.sh

代码语言：javascript

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/var/www/websocketd # /var/www/websocketd/websocketd --port=8888 --staticdir=. ./count.sh
Sun, 24 Dec 2023 11:29:57 +0800 | INFO   | server     |  | Serving using application   : ./count.sh

Sun, 24 Dec 2023 11:29:57 +0800 | INFO   | server     |  | Serving static content from : .

Sun, 24 Dec 2023 11:29:57 +0800 | INFO   | server     |  | Starting WebSocket server   : ws://4bc07756b82c/

Sun, 24 Dec 2023 11:29:57 +0800 | INFO   | server     |  | Serving CGI or static files : http://4bc07756b82c:8888/

Sun, 24 Dec 2023 11:30:01 +0800 | ACCESS | http       | url:'http://127.0.0.1/count.html' | STATIC

Sun, 24 Dec 2023 11:30:01 +0800 | ACCESS | session    | url:'http://127.0.0.1/' id:'1703388601564733656' remote:'172.18.0.1' command:'./count.sh' origin:'http://127.0.0.1' | CONNECT

Sun, 24 Dec 2023 11:30:11 +0800 | ACCESS | session    | url:'http://127.0.0.1/' id:'1703388601564733656' remote:'172.18.0.1' command:'./count.sh' origin:'http://127.0.0.1' pid:'3571' | DISCONNECT

访问地址：http://127.0.0.1/count.html

开发者模式

为了帮助开发、调试和测试，websocketd包括一个开发人员控制台，使您可以轻松地与WebSocket端点进行交互，而无需编写JavaScript。要启用控制台，请在websocketd命令行选项中添加 --devconsole 。

运行websocketd

代码语言：javascript

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/var/www/websocketd/websocketd --port=8888 --dir=/var/www/websocketd --devconsole

浏览器访问：http://127.0.0.1/counter.sh

其他

守护进程运行

代码语言：javascript

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nohup /var/www/websocketd/websocketd --port=8888 /var/www/websocketd/system_info.sh  >/dev/null  2>&1 &

证书加载

代码语言：javascript

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sudo websocketd

--port=8888

--ssl

--sslcert="/etc/letsencrypt/live/www.tinywan.com/fullchain.pem"

--sslkey="/etc/letsencrypt/live/www.tinywan.com//privkey.pem"

/var/www/websocketd/system.sh

Nginx代理配置

代码语言：javascript

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server {

listen 443 ssl http2;

server_name wallet.tinywan.com;
ssl_certificate /etc/letsencrypt/wallet.tinywan.com/full_chain.pem;
ssl_certificate_key /etc/letsencrypt/wallet.tinywan.com/private.key;

location /wssd
{
    proxy_pass http://127.0.0.1:8888;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection &#34;Upgrade&#34;;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_read_timeout 600;
}

}

连接方式

代码语言：javascript

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var ws = new WebSocket('wss://wallet.tinywan.com/wssd');