Shutdown a Node.js Server

1. Subscribe to the connection event which provides the socket for each new connection.
2. Remember each socket
3. Once the server.close() is called, close each socket separately using .destroy()

server.on('connection', socket => {
  sockets.push(socket);

  socket.on('close', () => {
    delete sockets[socketId];
  });
});

Node.js emits events when the process receives a signal. We can write a handler for these events.

const onExitHandler = signal => {
  console.log(`Received ${signal}. Exiting...`)
  server.close(() => {
    process.exit(0);
  });
}
process.on('SIGINT', onExitHandler);
process.on('SIGQUIT', onExitHandler);
process.on('SIGTERM', onExitHandler);