JAVA高级面试进阶训练营视频教程

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　　使用node.js开发webSocket开发代理，可以解决webSocket的cookies跨域问题。

　　这时有人会说，如果openstack的虚拟桌面流量太大，把代理冲内存溢出了，如何处理？

　　实际上，不是什么人都特别需要用WEB虚拟桌面操控虚拟机或物理机的，除非是windows系统，linux系统完全可以用流量更小的虚拟终端登陆。实际上进入linux虚拟桌面之后，好多操作不是还要用终端的吗？

　　业务层面，推荐使用linux系虚拟桌面的用户使用终端，甚至完全不提供虚拟桌面，这才是解决流量拥塞的方法。

　　然而想要在web上操纵linux终端，就需要通过 SSH 代理的方式调用并返回一个 shell 的虚拟终端（pty）的开源的 Web Terminal 项目。

　　这里为了防止SSH代理与项目耦合，导致代码难以查找，用node.js中间件或者Java的Springboot实现。

　　node.js的服务端实现（node.js对于websocket服务端的解决方法有二：原生websocket包和socket.io，后者可以在浏览器不支持的情况下转换为sockJS链接）：

var http = require('http');
var io = require('socket.io');
var utf8 = require('utf8');
var SSHClient = require('ssh2').Client;

var server2 = http.createServer(function(request, response) {
    console.log((new Date()) + ' Server is reseiveing on port 4041');
    response.writeHead(204);
    response.end();
});
server2.listen(4041, function() {
    console.log((new Date()) + ' Server is listening on port 4041');
});
io = io.listen(server2,{origins: '*:*'});
function createNewServer(machineConfig, socket) {
    var ssh = new SSHClient();
    let {msgId, ip, username, password, port, rows, cols} = machineConfig;
    ssh.on('ready', function () {
        socket.emit(msgId, '\r\n***' + ip + ' SSH CONNECTION ESTABLISHED ***\r\n');
        ssh.shell(function(err, stream) {
            if(rows != null && cols != null)
                stream.setWindow(rows, cols);
            if(err) {
                return socket.emit(msgId, '\r\n*** SSH SHELL ERROR: ' + err.message + ' ***\r\n');
            }
            socket.on(msgId, function (data) {
                var mydata = data.data;
                if(mydata != null){
                    console.log(">>>" + data.data + "<<<");
                    stream.write(mydata);
                }
                var size = data.rows;
                if(size != null){
                    stream.setWindow(data.rows, data.cols);
                }
            });
            stream.on('data', function (d) {
                try{
                    var mydata = utf8.decode(d.toString('binary'));
                    mydata = mydata.replace(/ \r(?!\n)/g,'');
                    console.log("<<<" + mydata + ">>>");
                    socket.emit(msgId, mydata);
                }catch(err){
                    socket.emit(msgId, '\r\n*** SSH CONNECTION ERROR: ' + err.message + ' ***\r\n');
                }
            }).on('close', function () {
                ssh.end();
            });
        })
    }).on('close', function () {
        socket.emit(msgId, '\r\n*** SSH CONNECTION CLOSED ***\r\n');
        ssh.end();
    }).on('error', function (err) {
        console.log(err);
        socket.emit(msgId, '\r\n*** SSH CONNECTION ERROR: ' + err.message + ' ***\r\n');
        ssh.end();
    }).connect({
        host: ip,
        port: port,
        username: username,
        password: password
    });
}

io.on('connection', function(socket) {
    socket.on('createNewServer', function(machineConfig) {//新建一个ssh连接
        console.log("createNewServer");
        createNewServer(machineConfig, socket);
    })

    socket.on('disconnect', function(){
        console.log('user disconnected');
    });
})

node ssh代理

　　Vue.js代码这样写（需导入xterm）：

<template>
</template>
 
<script>
import 'xterm/dist/xterm.css'
import { Terminal } from 'xterm';
import * as fit from 'xterm/dist/addons/fit/fit';
import * as fullscreen from 'xterm/dist/addons/fullscreen/fullscreen'
import openSocket from 'socket.io-client';
    export default {
      name: 'sshweb',
      props:['ip','port'],
        data () {
            return {
            wsServer:null,
            localip:'',
            localport:'',
            env: "",
            podName: "",
            contaName: "",
            logtxt: "",
            term:[0,0],
            colsLen:9,
            rowsLen:19,
            colRemain:21,
            msgId:0,
            col:80,
            row:24,
             terminal: {
                    pid: 1,
                    name: 'terminal',
                    cols: 80,
                    rows: 24
                  },
                
            }
        },
        watch:{
            port(val){
            this.localport=port;
            },
            ip(val){
            this.localip=ip;
            }
        },
        methods: {
            S4() {
                return (((1+Math.random())*0x10000)|0).toString(16).substring(1);
            },
            guid() {
                return (this.S4()+this.S4()+"-"+this.S4()+"-"+this.S4()+"-"+this.S4()+"-"+this.S4()+this.S4()+this.S4());
            },
            createServer1(){
                this.msgId = this.guid();
                var msgId = this.msgId;
                var myserver = this.wsServer;
                var selfy = this;
                var ipport = this.$route.params.ipport.split(':');
                var myport = ipport[0];
                var myip = ipport[1];
                myserver.emit("createNewServer", {msgId: msgId, ip: myport, username: "root", password: "xunfang", port: myip, rows: this.term[0].rows, cols: this.term[0].cols});
                let term = this.term[0];
                term.on("data", function(data) {
                    myserver.emit(msgId, {'data':data});
                });
                
                myserver.on(msgId, function (data) {
                    term.write(data);
                });
                term.attachCustomKeyEventHandler(function(ev) {
                    if (ev.keyCode == 86 && ev.ctrlKey) {
                        myserver.emit(msgId, new TextEncoder().encode("\x00" + this.copy));
                    }
                });
                myserver.on('connect_error', function(data){
                    console.log(data + ' - connect_error');
                });
                myserver.on('connect_timeout', function(data){
    console.log(data + ' - connect_timeout');
});
myserver.on('error', function(data){
    console.log(data + ' - error');
});
myserver.on('disconnect', function(data){
    console.log(data + ' - disconnect');
});
myserver.on('reconnect', function(data){
    console.log(data + ' - reconnect');
});
myserver.on('reconnect_attempt', function(data){
    console.log(data + ' - reconnect_attempt');
});
myserver.on('reconnecting', function(data){
    console.log(data + ' - reconnecting');
});
myserver.on('reconnect_error', function(data){
    console.log(data + ' - reconnect_error');
});
myserver.on('reconnect_failed', function(data){
    console.log(data + ' - reconnect_failed');
});
myserver.on('ping', function(data){
    console.log(data + ' - ping');
});
myserver.on('pong', function(data){
    console.log(data + ' - pong');
});
            },
            resize(row,col){
                row = Math.floor(row/this.rowsLen);
                col = Math.floor((col-this.colRemain)/this.colsLen);
                if(row<24)row=24;
                if(col<80)col=80;
                if(this.row != row || this.col != col){
                    this.row=row;
                    this.col=col;
                    this.term[0].fit();
                    //this.term[0].resize(col,row);
                    this.wsServer.emit(this.msgId, {'rows':this.term[0].rows.toString(),'cols':this.term[0].cols.toString()});
                    //this.wsServer.emit(this.msgId, {'rows':row.toString(),'cols':col.toString()});
                }
            }
        },
        mounted(){
            this.wsServer = new openSocket('ws://127.0.0.1:4041');
            var selfy = this;
            window.onload = function(){
                for(var i = 0;i < 1;i++){
                    var idname = 'net0';
                    Terminal.applyAddon(fit);
                    Terminal.applyAddon(fullscreen);
                    var terminalContainer = document.getElementById('app');
                    //terminalContainer.style.height = (selfy.rowsLen * selfy.terminal.rows).toString() + 'px' ;
                    //terminalContainer.style.width = (selfy.colsLen * selfy.terminal.cols + selfy.colRemain).toString() + 'px' ;
                    selfy.term = new Terminal({
                        cursorBlink: true
                    });
                    selfy.term.open(terminalContainer, true);
                    if(window.innerWidth > 0 && window.innerHeight > 0)
                        selfy.term.fit();
                    selfy.createServer1();
                }
            }
            $(window).resize(() =>{
                if(window.innerWidth > 0 && window.innerHeight > 0){
                    selfy.resize(window.innerHeight, window.innerWidth);
                }
            });
        },
        components: {
        }
    }
</script>
 
<style scoped>
#app{height:100%;width:100%;}
</style>

Vue.js的ssh客户端

　　打开服务器和Vue系统，登陆这个客户端上SSH，大功告成！

　　Java部分：

　　这里有个完整的解决方案，在我改正过的github仓库里。

　　这里说一下websocket连接代码：

　　vip.r0n9.ws.WebSshHandler：

package vip.r0n9.ws;

import com.jcraft.jsch.JSchException;
import org.springframework.stereotype.Component;
import vip.r0n9.util.SshSession;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.*;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

@ServerEndpoint(value = "/ssh/{id}", configurator = WebSocketConfigrator.class)
@Component
public class WebSshHandler {

    private static Map<String, SshSession> map = new ConcurrentHashMap<String, SshSession>();

    @OnOpen
    public void onOpen(final Session session, @PathParam("id") String id) throws JSchException, IOException, EncodeException, InterruptedException {
        System.out.println("有新链接 " + session.getUserProperties().get("ClientIP") + " 加入!当前在线人数为" + getOnlineCount());

        Map<String,String> parammap = new HashMap<String,String>();
        String[] param =  session.getQueryString().split("&");
        for(String keyvalue:param){
           String[] pair = keyvalue.split("=");
           if(pair.length==2){
               parammap.put(pair[0], pair[1]);
           }
        }
        
        String hostname = parammap.get("hostname");
        String password = parammap.get("password");
        Integer port,cols,rows;
        try {
            port = Integer.valueOf(parammap.get("port"));
        }catch(Exception e) {
            port = 22;
        }
        String username = parammap.get("username");
        try {
            rows = Integer.valueOf(parammap.get("rows"));
        }catch(Exception e) {
            rows = 24;
        }
        try {
            cols = Integer.valueOf(parammap.get("cols"));
        }catch(Exception e) {
            cols = 80;
        }
        
        SshSession sshSession;
        sshSession = new SshSession(hostname, port, username, password, session, rows, cols);
        map.put(session.getId(), sshSession);
    }

    @OnClose
    public void onClose(Session session) {
        SshSession sshsession = map.remove(session.getId());
        sshsession.close();
    }

    @OnMessage
    public void onMessage(String message, Session session) throws IOException, JSchException {
        map.get(session.getId()).getMessage(message);
    }
    
    @OnError
    public void onError(Session session, Throwable throwable) {
        throwable.printStackTrace();
        try {
            session.getBasicRemote().sendText(throwable.getMessage());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    public static synchronized int getOnlineCount() {
        return map.size();
    }
}

WebSshController.java

　　这里就是websocket服务端代码，连接websocket首先要在这里进行处理。

　　vip.r0n9.util.SshSession:

package vip.r0n9.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.nio.ByteBuffer;
import java.util.Iterator;

import javax.websocket.Session;

import com.fasterxml.jackson.databind.JsonNode;
import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelShell;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;

import vip.r0n9.JsonUtil;
import vip.r0n9.ws.WebSshHandler;

public class SshSession {

    private Session websession;//从客户端发起的websocket连接

    private StringBuilder dataToDst = new StringBuilder();

    private JSch jsch = new JSch();//ssh客户端

    private com.jcraft.jsch.Session jschSession;//ssh服务端返回的单个客户端连接

    private ChannelShell channel;

    private InputStream inputStream;
    private BufferedReader stdout;

    private OutputStream outputStream;
    private PrintWriter printWriter;
    
    public SshSession() {}
    
    public SshSession(String hostname,int port,String username, String password, final Session session2, int rows, int cols) throws JSchException, IOException {
        this.websession = session2;
        jschSession = jsch.getSession(username, hostname, port);
        jschSession.setPassword(password);
        java.util.Properties config = new java.util.Properties();
        config.put("StrictHostKeyChecking", "no");
        jschSession.setConfig(config);
        jschSession.connect();

        channel = (ChannelShell) jschSession.openChannel("shell");
        channel.setPty(true);
        channel.setPtyType("xterm");
        channel.setPtySize(cols, rows, cols*8, rows*16);
        inputStream = channel.getInputStream();
        
        outputStream = channel.getOutputStream();
        printWriter = new PrintWriter(outputStream,false);
        channel.connect();
        
        outputStream.write("\r".getBytes());
        outputStream.flush();
        //这里可以用newFixedThreadPool线程池，可以更方便管理线程
        Thread thread = new Thread() {

            @Override
            public void run() {

                try {
                    byte[] byteset = new byte[3072];
                    int res = inputStream.read(byteset);
                    if(res == -1)res = 0;
                    while (session2 != null && session2.isOpen()) { // 这里会阻塞，所以必须起线程来读取channel返回内容
                        ByteBuffer byteBuffer = ByteBuffer.wrap(byteset, 0, res);
                        synchronized (this) {
                            if(res != 0)
                                session2.getBasicRemote().sendBinary(byteBuffer);
                        }
                        res = inputStream.read(byteset);
                        if(res == -1)res = 0;
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        };
        thread.start();
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
    
    public void close() {
        channel.disconnect();
        jschSession.disconnect();
        try {
            this.websession.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            this.inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            this.outputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    public void getMessage(String message) throws IOException, JSchException {

        Session mysession = this.websession;
        System.out.println("来自客户端 " + mysession.getUserProperties().get("ClientIP") + " 的消息:" + message);

        JsonNode node = JsonUtil.strToJsonObject(message);

        if (node.has("resize")) {
            Iterator<JsonNode> myiter = node.get("resize").elements();
            int col = myiter.next().asInt();
            int row = myiter.next().asInt();
            channel.setPtySize(col, row, col*8, row*16);
            return;
        }

        if (node.has("data")) {
            String str = node.get("data").asText();

            outputStream.write(str.getBytes("utf-8"));
            outputStream.flush();

            return;
        }

    }

    public StringBuilder getDataToDst() {
        return dataToDst;
    }

    public OutputStream getOutputStream() {
        return outputStream;
    }

}

SshSession.java

　　代理SSH客户端的核心逻辑在此，这里要注意不要用Reader和Writer，一些终端功能会无法运行。

　　下载项目，开启Springboot，在浏览器上访问http://localhost:10003/，会进入登录页面，目前不支持RSA秘钥登录，只支持账号密码登录。

　　客户端也可以用Vue.js实现：

<template>
</template>
 
<script>
import 'xterm/dist/xterm.css'
import { Terminal } from 'xterm';
import * as fit from 'xterm/dist/addons/fit/fit';
import * as fullscreen from 'xterm/dist/addons/fullscreen/fullscreen'
import openSocket from 'socket.io-client';
    export default {
      name: 'sshweb',
      props:['ip','port'],
        data () {
            return {
            wsServer:null,
            localip:'',
            localport:'',
            env: "",
            podName: "",
            contaName: "",
            logtxt: "",
            term:[0,0],
            colsLen:9,
            rowsLen:19,
            colRemain:21,
            msgId:0,
            col:80,
            row:24,
             terminal: {
                    pid: 1,
                    name: 'terminal',
                    cols: 80,
                    rows: 24
                  },
                
            }
        },
        watch:{
            port(val){
            this.localport=port;
            },
            ip(val){
            this.localip=ip;
            }
        },
        methods: {
            S4() {
                return (((1+Math.random())*0x10000)|0).toString(16).substring(1);
            },
            guid() {
                return (this.S4()+this.S4()+"-"+this.S4()+"-"+this.S4()+"-"+this.S4()+"-"+this.S4()+this.S4()+this.S4());
            },
            createServer1(){
                this.msgId = this.guid();
                var msgId = this.msgId;
                var selfy = this;
                var ipport = this.$route.params.ipport.split(':');
                var myport = ipport[1];
                var myip = ipport[0];
                var wsurl = 'ws://127.0.0.1:10003/ssh/1?hostname=' + myip + '&port=' + myport + '&username=root&password=xunfang';
                this.wsServer = new WebSocket(wsurl);
                var myserver = this.wsServer;
                let term = this.term[0];
                term.on("data", function(data) {
                    var you = data;
                    if(you.length > 1)you = you[0];
                    console.log(you.charCodeAt());
                    myserver.send(JSON.stringify({'data': data}));
                });
                
                myserver.onopen = function(evt) {
                    console.log(evt);
                };
                
                myserver.onmessage = function(msg) {
                    var reader = new window.FileReader();
                    var isend = false;

                    reader.onloadend = function(){
                        var decoder = new window.TextDecoder('utf-8');
                        console.log(decoder);
                        var text = decoder.decode(reader.result);
                        console.log(text);
                        term.write(text);
                    };
                    
                    reader.readAsArrayBuffer(msg.data);
                };
                term.attachCustomKeyEventHandler(function(ev) {
                    if (ev.keyCode == 86 && ev.ctrlKey) {
                        myserver.send(JSON.stringify({'data': new TextEncoder().encode("\x00" + this.copy)}));
                    }
                });
            },
            resize(row,col){
                row = Math.floor(row/this.rowsLen);
                col = Math.floor((col-this.colRemain)/this.colsLen);
                if(row<24)row=24;
                if(col<80)col=80;
                if(this.row != row || this.col != col){
                    this.row=row;
                    this.col=col;
                    this.term[0].fit();
                    myserver.send(JSON.stringify({'resize': [cols, rows]}));
                }
            }
        },
        mounted(){
            var selfy = this;
            window.onload = function(){
                for(var i = 0;i < 1;i++){
                    var idname = 'net0';
                    Terminal.applyAddon(fit);
                    Terminal.applyAddon(fullscreen);
                    var terminalContainer = document.getElementById('app');
                    selfy.term = new Terminal({
                        cursorBlink: true
                    });
                    selfy.term.open(terminalContainer, true);
                    if(window.innerWidth > 0 && window.innerHeight > 0)
                        selfy.term.fit();
                    selfy.createServer1();
                }
            }
            $(window).resize(() =>{
                if(window.innerWidth > 0 && window.innerHeight > 0){
                    selfy.resize(window.innerHeight, window.innerWidth);
                }
            });
        },
        components: {
        }
    }
</script>
 
<style scoped>
#app{height:100%;width:100%;}
</style>

sshClient.vue

　　两个项目的SSH窗口都是全屏的，只要窗口不小于某个大小，窗口的字会随着窗口缩放而调整位置。

　　虚拟终端演示：