web-to-fish/main.js

import express from 'express';
import path from 'path';
import { fileURLToPath } from 'url';
import expressWs from 'express-ws';
import { spawn } from 'node-pty';
// import json from './secrets/config.json' with { type: 'json' };

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const PORT = process.env.PORT || 5164;
const app = express();

expressWs(app); // enable websockets for the app

// parse form data
app.use(express.urlencoded({ extended: true }));
app.use(express.json({ extended: true }));
app.use('/node_modules', express.static('node_modules'));

// map of active sessions
const sessions = new Map();

// shell interface
app.get('/', (req, res) => {
	res.sendFile('shell.html', { root: path.join(__dirname, 'HTML') });
});

// websocket endpoint that spawns/attaches to a fish shell
app.ws('/shell-ws', (ws, req) => {
	const { id } = req.query;
	if (!id) {
		ws.close();
		return;
	}

	let session = sessions.get(id);
	if (!session) {
		const shell = spawn('su', ['-', 'ion606', '-s', '/usr/bin/fish'], {
			cols: 80,
			rows: 24,
			cwd: process.env.HOME,
			env: process.env
		});

		session = { shell, clients: new Set() };
		sessions.set(id, session);

		shell.onData((data) => {
			for (const client of session.clients) {
				client.send(JSON.stringify({ data }));
			}
		});

		shell.onExit((e) => {
			for (const client of session.clients) {
				client.send(JSON.stringify({ event: 'exit', code: e }));
			}
			sessions.delete(id);
		});
	}

	session.clients.add(ws);
	ws.on('message', (msg) => session.shell.write(msg));

	ws.on('close', () => {
		session.clients.delete(ws);
	});
});

// endpoint used by the client to explicitly close a session
app.post('/kill-session', (req, res) => {
	const { id } = req.query;
	const session = sessions.get(id);
	if (session) {
		session.shell.kill();
		sessions.delete(id);
	}
	res.end();
});

app.get('*', (req, res) => res.end());

app.listen(PORT, '0.0.0.0', () =>
	console.log(`server listening on http://localhost:${PORT}`)
);