feat: Add server availability check API and integrate it into the Dashboard and ServerManager components for enhanced server monitoring and user experience

backend/server.js

@@ -5,6 +5,7 @@ const cors = require('cors');
 const path = require('path');
 const compression = require('compression');
 const Ajv = require('ajv');
+const net = require('net');
 
 const app = express();
 const port = 3001;
@@ -1395,6 +1396,55 @@ app.get('/api/auto-urls', async (req, res) => {
     }
 });
 
+// --- Servers availability check ---
+// Simple TCP connect check to 80 then 443 with short timeouts
+function tcpCheck(host, port, timeoutMs) {
+  return new Promise((resolve) => {
+    const socket = new net.Socket();
+    let settled = false;
+    const onOk = () => { if (!settled) { settled = true; try{ socket.destroy(); }catch{} resolve(true); } };
+    const onFail = () => { if (!settled) { settled = true; try{ socket.destroy(); }catch{} resolve(false); } };
+    socket.setTimeout(timeoutMs);
+    socket.once('error', onFail);
+    socket.once('timeout', onFail);
+    socket.connect(port, host, onOk);
+  });
+}
+
+async function checkOneServer(srv, timeoutMs = 1500) {
+  const hostCandidates = [];
+  if (srv.ip) hostCandidates.push(srv.ip);
+  if (srv.dns) hostCandidates.push(srv.dns);
+  for (const host of hostCandidates) {
+    // try 80 then 443
+    const ok80 = await tcpCheck(host, 80, timeoutMs);
+    if (ok80) return true;
+    const ok443 = await tcpCheck(host, 443, timeoutMs);
+    if (ok443) return true;
+  }
+  return false;
+}
+
+app.get('/api/servers/availability', async (req, res) => {
+  try {
+    const data = await s3.getObject({ Bucket: BUCKET_NAME, Key: 'servers.json' }).promise();
+    let servers = [];
+    try {
+      servers = JSON.parse(data.Body.toString('utf-8'));
+      if (!Array.isArray(servers)) servers = [];
+    } catch {
+      servers = [];
+    }
+    const checks = await Promise.allSettled(servers.map(s => checkOneServer(s)));
+    const statuses = servers.map((s, i) => ({ ip: s.ip, dns: s.dns, online: checks[i].status === 'fulfilled' ? Boolean(checks[i].value) : false }));
+    const online = statuses.filter(x => x.online).length;
+    res.json({ online, total: servers.length, statuses });
+  } catch (e) {
+    console.error('availability error', e);
+    res.status(500).json({ online: 0, total: 0, statuses: [] });
+  }
+});
+
 // Update auto URLs in S3
 app.post('/api/auto-urls', async (req, res) => {
     const { urls } = req.body;