close-with-grace

What is close-with-grace?

The 'close-with-grace' npm package helps manage graceful shutdowns in Node.js applications. It allows you to handle termination signals and perform cleanup tasks before the application exits, ensuring that resources are properly released and ongoing operations are completed.

What are close-with-grace's main functionalities?

Graceful Shutdown on SIGINT

This feature allows the application to handle the SIGINT signal (usually triggered by Ctrl+C) and perform cleanup tasks before shutting down. The provided code sample demonstrates how to set up a graceful shutdown with a delay and cleanup logic.

const closeWithGrace = require('close-with-grace');

const closeListeners = closeWithGrace({ delay: 500 }, async ({ err }) => {
  if (err) {
    console.error('Error during shutdown', err);
  }
  console.log('Cleaning up before shutdown...');
  await new Promise(resolve => setTimeout(resolve, 100));
  console.log('Cleanup complete.');
});

process.on('SIGINT', () => {
  console.log('Received SIGINT');
  closeListeners.uninstall();
});

Handling Multiple Signals

This feature allows the application to handle multiple termination signals (e.g., SIGTERM and SIGINT) and perform cleanup tasks before shutting down. The provided code sample demonstrates how to set up graceful shutdown handling for both SIGTERM and SIGINT signals.

const closeWithGrace = require('close-with-grace');

const closeListeners = closeWithGrace({ delay: 500 }, async ({ err }) => {
  if (err) {
    console.error('Error during shutdown', err);
  }
  console.log('Cleaning up before shutdown...');
  await new Promise(resolve => setTimeout(resolve, 100));
  console.log('Cleanup complete.');
});

process.on('SIGTERM', () => {
  console.log('Received SIGTERM');
  closeListeners.uninstall();
});

process.on('SIGINT', () => {
  console.log('Received SIGINT');
  closeListeners.uninstall();
});

Custom Cleanup Logic

This feature allows the application to define custom cleanup logic that will be executed before the application shuts down. The provided code sample demonstrates how to set up a graceful shutdown with custom cleanup logic and a delay.

const closeWithGrace = require('close-with-grace');

const closeListeners = closeWithGrace({ delay: 1000 }, async ({ err }) => {
  if (err) {
    console.error('Error during shutdown', err);
  }
  console.log('Performing custom cleanup...');
  // Custom cleanup logic here
  await new Promise(resolve => setTimeout(resolve, 500));
  console.log('Custom cleanup complete.');
});

Other packages similar to close-with-grace

graceful-shutdown

The 'graceful-shutdown' package provides similar functionality for handling graceful shutdowns in Node.js applications. It allows you to register shutdown handlers and ensures that cleanup tasks are completed before the application exits. Compared to 'close-with-grace', 'graceful-shutdown' offers a more straightforward API but may lack some advanced features.

node-graceful-shutdown

The 'node-graceful-shutdown' package helps manage graceful shutdowns by providing a mechanism to handle termination signals and perform cleanup tasks. It is similar to 'close-with-grace' in terms of functionality but offers a different API design. 'node-graceful-shutdown' focuses on simplicity and ease of use.

http-terminator

The 'http-terminator' package is designed to facilitate graceful shutdowns of HTTP servers in Node.js. It ensures that all ongoing requests are completed before the server shuts down. While 'http-terminator' is more specialized for HTTP servers, 'close-with-grace' offers a more general-purpose solution for handling various types of cleanup tasks.

README

close-with-grace

Exit your process, gracefully (if possible) - for Node.js

Install

npm i close-with-grace

Usage

const closeWithGrace = require('close-with-grace')

// delay is the number of milliseconds for the graceful close to
// finish.
closeWithGrace({ delay: 500 }, async function ({ signal, err, manual }) {
  if (err) {
    console.error(err)
  }
  await closeYourServer()
})

// default delay is 10000
// to disable delay feature at all, pass falsy value to delay option.
closeWithGrace({ delay: false }, () => await somethingUseful())

Injecting custom logger

const closeWithGrace = require('close-with-grace')

// delay is the number of milliseconds for the graceful close to
// finish.
closeWithGrace(
  {
    delay: 500,
    logger: { error: (m) => console.error(`[close-with-grace] ${m}`) }
  },
  async function ({ signal, err, manual }) {
  if (err) {
    console.error(err)
  }
  await closeYourServer()
})

// default logger is console
// to disable logging at all, pass falsy value to logger option.
closeWithGrace({ logger: false }, () => await somethingUseful())

Example with Fastify

import fastify from 'fastify'
import closeWithGrace from 'close-with-grace'

const app = fastify()

closeWithGrace(async function ({ signal, err, manual }) {
  if (err) {
    app.log.error({ err }, 'server closing with error')
  } else {
    app.log.info(`${signal} received, server closing`)
  }
  await app.close()
})

await app.listen()

API

closeWithGrace([opts], fn({ err, signal, manual }))

closeWithGrace adds a global listeners to the events:

• process.once('SIGHUP')
• process.once('SIGINT')
• process.once('SIGQUIT')
• process.once('SIGILL')
• process.once('SIGTRAP')
• process.once('SIGABRT')
• process.once('SIGBUS')
• process.once('SIGFPE')
• process.once('SIGSEGV')
• process.once('SIGUSR2')
• process.once('SIGTERM')
• process.once('uncaughtException')
• process.once('unhandledRejection')
• process.once('beforeExit')

In case one of them is emitted, it will call the given function. If it is emitted again, it will terminate the process abruptly.

opts

• delay: the numbers of milliseconds before abruptly close the process. Default: 10000.

  • Pass false, null or undefined to disable this feature.

• logger: instance of logger which will be used internally. Default: console.

  • Pass false, null or undefined to disable this feature.

fn({ err, signal, manual } [, cb])

Execute the given function to perform a graceful close. The function can either return a Promise or call the callback. If this function does not error, the process will be closed with exit code 0. If the function rejects with an Error, or call the callback with an Error as first argument, the process will be closed with exit code 1.

return values

Calling closeWithGrace() will return an object as formed:

• close(): close the process, the manual argument will be set to true.
• uninstall(): remove all global listeners.

License

MIT