Node HTTP Server Destroy Sockets

server.ts

/*!
 * Destroy all open connections so a server can close.
 * Inspired by https://github.com/marten-de-vries/killable
 */

import http from 'http';
import { Socket } from 'net';

// Set of open sockets
const sockets: Set<Socket> = new Set();

const signals: Array<NodeJS.Signals> = ['SIGINT', 'SIGTERM', 'SIGUSR2'];

const server = http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  // Don't end the response to keep the connection open
  // res.end('OK');
});

server.on('connection', (socket) => {
  // Add the new socket to the set
  sockets.add(socket);

  // Once the socket closes it can be removed from the set
  socket.once('close', () => {
    sockets.delete(socket);
  });
});

server.on('listening', () => {
  console.log('Listening');
});

// Emitted once all sockets have been closed
server.on('close', () => {
  process.exit(0);
});

server.listen(8080);

signals.forEach((signal) => {
  process.on(signal, () => {
    console.log('Closing');

    // Stop accepting incoming connections
    server.close();
    
    // Destroy each socket
    sockets.forEach((socket) => {
      socket.destroy();
    });
  });
});