fixed issues w/ accessing website on other computers

dashboard/server.mjs

@@ -1,10 +1,12 @@
 import { createReadStream, realpathSync, statSync } from "node:fs";
 import { createServer } from "node:http";
+import { networkInterfaces } from "node:os";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
 
 const ROOT = realpathSync(path.dirname(fileURLToPath(import.meta.url)));
-const HOST = process.env.HOST || "127.0.0.1";
+const LAN_MODE = process.argv.includes("--lan");
+const HOST = LAN_MODE ? "0.0.0.0" : process.env.HOST || "127.0.0.1";
 const PORT = Number.parseInt(process.env.PORT || "4173", 10);
 const TYPES = new Map([
   [".css", "text/css; charset=utf-8"],
@@ -50,6 +52,28 @@ function safeFile(requestUrl) {
   }
 }
 
+function displayUrls(host, port) {
+  if (host !== "0.0.0.0") {
+    const displayHost = host === "::" ? "::1" : host;
+    const urlHost = displayHost.includes(":") ? `[${displayHost}]` : displayHost;
+    return [{ label: "Open", url: `http://${urlHost}:${port}` }];
+  }
+
+  const entries = [{ label: "This computer", url: `http://127.0.0.1:${port}` }];
+  const seen = new Set();
+  for (const [interfaceName, addresses] of Object.entries(networkInterfaces())) {
+    for (const address of addresses || []) {
+      if (address.family !== "IPv4" || address.internal || seen.has(address.address)) continue;
+      seen.add(address.address);
+      entries.push({
+        label: `Other devices (${interfaceName})`,
+        url: `http://${address.address}:${port}`,
+      });
+    }
+  }
+  return entries;
+}
+
 const server = createServer((request, response) => {
   if (!request.url || !["GET", "HEAD"].includes(request.method || "")) {
     response.writeHead(405, { Allow: "GET, HEAD" });
@@ -66,7 +90,7 @@ const server = createServer((request, response) => {
   const extension = path.extname(file).toLowerCase();
   response.writeHead(200, {
     "Content-Type": TYPES.get(extension) || "application/octet-stream",
-    "Cache-Control": extension === ".json" ? "no-store" : "public, max-age=300",
+    "Cache-Control": "no-store",
     "X-Content-Type-Options": "nosniff",
     "Referrer-Policy": "no-referrer",
   });
@@ -77,6 +101,22 @@ const server = createServer((request, response) => {
   createReadStream(file).on("error", () => response.destroy()).pipe(response);
 });
 
+server.on("error", (error) => {
+  if (error.code === "EADDRINUSE") {
+    process.stderr.write(
+      `Dashboard port ${PORT} is already in use. Stop the existing server or set a different PORT.\n`,
+    );
+  } else {
+    process.stderr.write(`Dashboard server could not start (${error.code || "unknown error"}).\n`);
+  }
+  process.exitCode = 1;
+});
+
 server.listen(PORT, HOST, () => {
-  process.stdout.write(`Utah Vehicle Health dashboard: http://${HOST}:${PORT}\n`);
+  const address = server.address();
+  const actualPort = typeof address === "object" && address ? address.port : PORT;
+  const urls = displayUrls(HOST, actualPort)
+    .map(({ label, url }) => `  ${label}: ${url}`)
+    .join("\n");
+  process.stdout.write(`Utah Vehicle Health dashboard:\n${urls}\n`);
 });