infrastructure-monitoring-dashboard/backend/server.js

import "dotenv/config";
import express from "express";
import cors from "cors";
import { providers } from "./providers/index.js";

const app = express();
const PORT = 3000;
const POLL_INTERVAL = 2 * 60 * 1000; // 2 minutes
const PROVIDER_TIMEOUT = 10 * 1000; // 10 seconds

app.use(cors());

let cachedStatuses = [];

function safeCheck(provider) {
  return Promise.race([
    provider.checkStatus(),
    new Promise((_, reject) =>
      setTimeout(() => reject(new Error("Timeout")), PROVIDER_TIMEOUT)
    ),
  ]).catch((err) => ({
    name: provider.name,
    status: "unknown",
    message: `Check failed: ${err.message}`,
    lastUpdated: new Date().toISOString(),
  })).then((result) => ({
    url: provider.url ?? null,
    ...result,
  }));
}

async function pollAll() {
  const results = await Promise.allSettled(providers.map(safeCheck));
  cachedStatuses = results.map((r) =>
    r.status === "fulfilled"
      ? r.value
      : {
          name: "Unknown",
          status: "unknown",
          message: "Provider check failed.",
          lastUpdated: new Date().toISOString(),
        }
  );
  console.log(
    `[${new Date().toISOString()}] Polled ${cachedStatuses.length} providers`
  );
}

app.get("/api/status", (_req, res) => {
  res.json(cachedStatuses);
});

app.get("/api/health", (_req, res) => {
  res.json({ ok: true, providers: providers.length });
});

// Poll immediately, then on interval
await pollAll();
setInterval(pollAll, POLL_INTERVAL);

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