1// The capsule's main internal port: GET /health is 200 while ttyd (the app, port 7681)2// accepts connections, 503 otherwise. A TCP connect, so ttyd logs nothing for it.3// Nothing else lives here; the terminal is the app port.4const http = require("http");5const net = require("net");67function ttydUp() {8  return new Promise((resolve) => {9    const sock = net.connect({ host: "127.0.0.1", port: 7681, timeout: 2000 });10    sock.on("connect", () => { sock.destroy(); resolve(true); });11    sock.on("error", () => resolve(false));12    sock.on("timeout", () => { sock.destroy(); resolve(false); });13  });14}1516http.createServer(async (req, res) => {17  if (req.method === "GET" && req.url === "/health") {18    const ok = await ttydUp();19    res.writeHead(ok ? 200 : 503, { "Content-Type": "application/json" });20    res.end(JSON.stringify({ status: ok ? "ok" : "starting" }));21    return;22  }23  res.writeHead(404, { "Content-Type": "application/json" });24  res.end('{"error":"not found"}');25}).listen(Number(process.env.M64_PORT || 9500), "0.0.0.0");