Repair Service Startup & Shutdown Failures

I have analyzed the lifecycle contract between Kubernetes and your Node.js process. The current implementation lacks a SIGTERM handler that pauses traffic admission and waits for the HTTP server to close existing connections within the 30-second window.

Graceful Shutdown Implementation

const express = require('express');
const http = require('http');

const app = express();
const server = http.createServer(app);

// Track active connections for draining
let isShuttingDown = false;

app.use((req, res, next) => {
  if (isShuttingDown) {
    res.set('Connection', 'close');
    res.status(503).send('Server is shutting down');
    return;
  }
  next();
});

function gracefulShutdown(signal) {
  console.log(`${signal} received. Starting graceful shutdown...`);
  isShuttingDown = true;

  // Stop accepting new connections via K8s readiness probe if applicable
  // Or simply stop the server from accepting new socket connections
  server.close(() => {
    console.log('Http server closed.');
    // Close DB connections, flush logs, etc. here
    process.exit(0);
  });

  // Force shutdown after a safety margin (e.g., 25s for a 30s K8s limit)
  setTimeout(() => {
    console.error('Could not close connections in time, forceful shutdown');
    process.exit(1);
  }, 25000);
}

process.on('SIGTERM', () => gracefulShutdown('SIGTERM'));
process.on('SIGINT', () => gracefulShutdown('SIGINT'));

server.listen(3000);

Next steps

1. Update your Kubernetes deployment manifest to ensure the readinessProbe points to a /health endpoint that returns 503 when isShuttingDown is true.
2. Verify that your containerized environment does not use an npm start wrapper that swallows signals; use node index.js directly in the Docker CMD.
3. Run the included implementation and trigger a manual kill -15 to verify the "Http server closed" log appears.