@jack2006/pangolin/proxyClient.js

pangolin is a fast reverse proxy to help you expose a local server behind a NAT or firewall to the internet. As of now, it supports tcp & udp, as well as http and https protocols, where requests can be forwarded to internal services by domain name.

const net = require('net');
const io = require('socket.io-client');
const colors = require('colors/safe');

class ClientServer {
  constructor(argv) {
    this.host = argv.host;
    if (!this.host) {
      console.log(colors.red('Error: Could not get host'));
    }

    this.port = argv.port || 27;
    if (!this.port) {
      console.log(colors.red('Error: Could not get port'));
    }
    if (argv.binds) {
      this.binds = argv.binds;
    }
    this.localConnectingSockets = {};
  }

  host;
  port;
  /*
   *  example:
      structure:
    {
    wall: {
      local_port: 8080,
      remote_port: 10004
    },
    www: {
      local_port: 8090,
      remote_port: 9080
    },//本地服务名=>端口映射
  }
   */
  binds = {};
  mainsSocket;

  logger = {
    info: console.log
  };

  init() {

    this.mainsSocket = io(`http://${this.host}:${this.port}`);
    // socket.on()用于接收服务端发来的消息
    this.mainsSocket.on('connect',  ()=>{

      console.log('client connect server');
      this.mainsSocket.emit('addBinds', this.binds);

      for (let serverKey in this.binds) {
        this.mainsSocket.on(serverKey, d => {
          // console.log(`data from front server: ${d}`);
          this.handleDataFromFrontServer(serverKey, d);
        });
      }
    });
  }

  createLocalConnectingSocket(serverKey, requestKey, data) {
    if (this.localConnectingSockets[requestKey]) {
      return;
    }
    const that = this;
    this.localConnectingSockets[requestKey] = net.connect({host: this.binds[serverKey].local_host, port: this.binds[serverKey].local_port}, () => {});
    this.localConnectingSockets[requestKey].on('data', function(data) {
      that.mainsSocket.emit(serverKey, { cmd: 'data', serverKey, requestKey, data });
    });
    this.localConnectingSockets[requestKey].on('error',err=>{
      console.error(err);
      that.handleWhenErrorOrClose(serverKey, requestKey);
    });
    this.localConnectingSockets[requestKey].on('close', () => {
      that.handleWhenErrorOrClose(serverKey, requestKey);
    });
  }

  handleWhenErrorOrClose(serverKey, requestKey) {
    if (!this.localConnectingSockets[requestKey]) {
      return;
    }
    this.localConnectingSockets[requestKey].end();
    this.localConnectingSockets[requestKey] = null;
    delete this.localConnectingSockets[requestKey];

    this.mainsSocket.emit(serverKey, { cmd: 'close', requestKey });
  }

  handleDataFromFrontServer(serverKey, d) {
    const { cmd, requestKey, data } = d;
    if (cmd === 'create') {
      this.createLocalConnectingSocket(serverKey, requestKey);
    } else if (cmd === 'data') {
      this.localConnectingSockets[requestKey].write(data);
    } else if (cmd === 'close') {
      console.log(`close requestKey: ${requestKey}`);
      if (!this.localConnectingSockets[requestKey]) {
        return;
      }
      this.localConnectingSockets[requestKey].end();
      this.localConnectingSockets[requestKey] = null;
      delete this.localConnectingSockets[requestKey];
    }
  }

  /*
   * binds: ex:['wall', 'www']
   */
  removeBinds(binds) {
    this.mainsSocket.emit('removeBinds', binds);
  }

  /*
   {
    wall: {
      local_port: 8080,
      remote_port: 10004
    }
   */
  addBinds(binds) {
    const remote_ports = [];
    for (let key in binds) {
      remote_ports.push(binds[key].remote_port);
      if (this.binds[key]) {
        throw `Error: the bind of '${key}' existed`
      }
    }

    for (let key in this.binds) {
      if (remote_ports.includes(this.binds[key].remote_port)) {
        throw `Error: the remote port of '${this.binds[key].remote_port}' existed`
      }
    }

    console.log(`before, binds: ${JSON.stringify(this.binds)}`);
    this.binds = {...this.binds, ...binds};
    console.log(`after, binds: ${JSON.stringify(this.binds)}`);
    this.mainsSocket.emit('addBinds', binds);
    for (let serverKey in binds) {
      this.mainsSocket.on(serverKey, d => {
        this.handleDataFromFrontServer(serverKey, d);
      });
    }
  }

  start() {
    this.init();
  }
}

module.exports = { ClientServer };