Node.js
Updated on October 27, 2026
Node.js
Any repository containing a package.json with a start script (and that doesn't match a more specific framework like Next.js) is treated as a generic Node.js service.
The rule that avoids 90% of problems
// ✅ Correct — reachable from Traefik
app.listen(process.env.PORT || 3000, "0.0.0.0");
// ❌ Incorrect — the service reports "Running" but stays unreachable
app.listen(3000, "localhost");
localhost inside a pod refers only to the pod itself: Traefik, which sits outside, cannot reach it.
Express
import express from "express";
const app = express();
app.use(express.json());
app.get("/health", (_req, res) => res.json({ ok: true }));
const port = process.env.PORT || 3000;
app.listen(port, "0.0.0.0", () => console.log(`listening on ${port}`));
Fastify
import Fastify from "fastify";
const app = Fastify();
app.get("/health", async () => ({ ok: true }));
await app.listen({ port: process.env.PORT || 3000, host: "0.0.0.0" });
Process management
The auto builder runs your start script directly. If your application needs a process supervisor (automatic restarts, cluster mode), use a custom start command with PM2 or equivalent.