observer effect content

services/observer-effect/devserver.mjs

@@ -0,0 +1,67 @@
+/* Local dev server: serves ./site and proxies /ws to the relay, so the pages
+   run same-origin exactly like they do behind nginx in production.
+
+   Usage:
+     OBSERVER_TOKEN=test cargo run            # in relay/, terminal 1
+     node devserver.mjs                       # terminal 2 -> http://localhost:8080
+   Env: PORT (default 8080), RELAY (default 127.0.0.1:8770). */
+
+import { createServer } from "node:http";
+import { connect } from "node:net";
+import { readFile } from "node:fs/promises";
+import { extname, join, normalize } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const PORT = Number(process.env.PORT || 8080);
+const [RELAY_HOST, RELAY_PORT] = (process.env.RELAY || "127.0.0.1:8770").split(":");
+const SITE = join(fileURLToPath(new URL(".", import.meta.url)), "site");
+
+const MIME = {
+  ".html": "text/html; charset=utf-8",
+  ".css": "text/css; charset=utf-8",
+  ".js": "text/javascript; charset=utf-8",
+  ".mp3": "audio/mpeg",
+  ".wav": "audio/wav",
+};
+
+const server = createServer(async (req, res) => {
+  let path = decodeURIComponent(req.url.split("?")[0]);
+  if (path === "/") path = "/clock.html";
+  if (path === "/control") path = "/control.html";
+
+  // keep it inside SITE
+  const file = join(SITE, normalize(path));
+  if (!file.startsWith(SITE)) {
+    res.writeHead(403).end("forbidden");
+    return;
+  }
+  try {
+    const body = await readFile(file);
+    res.writeHead(200, { "content-type": MIME[extname(file)] || "application/octet-stream" });
+    res.end(body);
+  } catch {
+    res.writeHead(404).end("not found");
+  }
+});
+
+// Proxy the WebSocket upgrade straight through to the relay.
+server.on("upgrade", (req, socket, head) => {
+  const upstream = connect(Number(RELAY_PORT), RELAY_HOST, () => {
+    const lines = [`${req.method} ${req.url} HTTP/1.1`];
+    for (let i = 0; i < req.rawHeaders.length; i += 2) {
+      lines.push(`${req.rawHeaders[i]}: ${req.rawHeaders[i + 1]}`);
+    }
+    upstream.write(lines.join("\r\n") + "\r\n\r\n");
+    if (head && head.length) upstream.write(head);
+    socket.pipe(upstream);
+    upstream.pipe(socket);
+  });
+  const bail = () => socket.destroy();
+  upstream.on("error", bail);
+  socket.on("error", () => upstream.destroy());
+});
+
+server.listen(PORT, () => {
+  console.log(`observer-effect dev server: http://localhost:${PORT}/  (control: /control)`);
+  console.log(`proxying /ws -> ${RELAY_HOST}:${RELAY_PORT}`);
+});