github.com/Ilhicas/nomad@v1.0.4-0.20210304152020-e86851182bc3/ui/app/utils/classes/exec-socket-xterm-adapter.js (about)

     1  const ANSI_UI_GRAY_400 = '\x1b[38;2;142;150;163m';
     2  
     3  import base64js from 'base64-js';
     4  import { TextDecoderLite, TextEncoderLite } from 'text-encoder-lite';
     5  
     6  export const HEARTBEAT_INTERVAL = 10000; // ten seconds
     7  
     8  export default class ExecSocketXtermAdapter {
     9    constructor(terminal, socket, token) {
    10      this.terminal = terminal;
    11      this.socket = socket;
    12      this.token = token;
    13  
    14      socket.onopen = () => {
    15        this.sendWsHandshake();
    16        this.sendTtySize();
    17        this.startHeartbeat();
    18  
    19        terminal.onData(data => {
    20          this.handleData(data);
    21        });
    22      };
    23  
    24      socket.onmessage = e => {
    25        let json = JSON.parse(e.data);
    26  
    27        // stderr messages will not be produced as the socket is opened with the tty flag
    28        if (json.stdout && json.stdout.data) {
    29          terminal.write(decodeString(json.stdout.data));
    30        }
    31      };
    32  
    33      socket.onclose = () => {
    34        this.stopHeartbeat();
    35        this.terminal.writeln('');
    36        this.terminal.write(ANSI_UI_GRAY_400);
    37        this.terminal.writeln('The connection has closed.');
    38        // Issue to add interpretation of close events: https://github.com/hashicorp/nomad/issues/7464
    39      };
    40  
    41      terminal.resized = () => {
    42        this.sendTtySize();
    43      };
    44    }
    45  
    46    sendTtySize() {
    47      this.socket.send(
    48        JSON.stringify({ tty_size: { width: this.terminal.cols, height: this.terminal.rows } })
    49      );
    50    }
    51  
    52    sendWsHandshake() {
    53      this.socket.send(JSON.stringify({ version: 1, auth_token: this.token || '' }));
    54    }
    55  
    56    startHeartbeat() {
    57      this.heartbeatTimer = setInterval(() => {
    58        this.socket.send(JSON.stringify({}));
    59      }, HEARTBEAT_INTERVAL);
    60    }
    61  
    62    stopHeartbeat() {
    63      clearInterval(this.heartbeatTimer);
    64    }
    65  
    66    handleData(data) {
    67      this.socket.send(JSON.stringify({ stdin: { data: encodeString(data) } }));
    68    }
    69  }
    70  
    71  function encodeString(string) {
    72    let encoded = new TextEncoderLite('utf-8').encode(string);
    73    return base64js.fromByteArray(encoded);
    74  }
    75  
    76  function decodeString(b64String) {
    77    let uint8array = base64js.toByteArray(b64String);
    78    return new TextDecoderLite('utf-8').decode(uint8array);
    79  }