http-shutdown/readme.md

Gracefully shutdown a running HTTP server.

# Http-Shutdown [![NPM version][npm-image]][npm-url] [![Build status][travis-image]][travis-url] [![Test coverage][coveralls-image]][coveralls-url]
Shutdown a Nodejs HTTP server gracefully by doing the following:

1. Close the listening socket to prevent new connections
2. Close all idle keep-alive sockets to prevent new requests during shutdown
3. Wait for all in-flight requests to finish before closing their sockets.
4. Profit!

Other solutions might just use `server.close` which only terminates the listening socket and waits for other sockets to close - which is incomplete since keep-alive sockets can still make requests. Or, they may use `ref()/unref()` to simply cause Nodejs to terminate if the sockets are idle - which doesn't help if you have other things to shutdown after the server shutsdown.

`http-shutdown` is a complete solution. It uses idle indicators combined with an active socket list to safely, and gracefully, close all sockets. It does not use `ref()/unref()` but, instead, actively closes connections as they finish meaning that socket 'close' events still work correctly since the sockets are actually closing - you're not just `unref`ing and forgetting about them.

## Installation

```bash
$ npm install http-shutdown
```

## Usage
There are currently two ways to use this library. The first is explicit wrapping of the `Server` object:

```javascript
// Create the http server
var server = require('http').createServer(function(req, res) {
  res.end('Good job!');
});

// Wrap the server object with additional functionality.
// This should be done immediately after server construction, or before you start listening.
// Additional functionailiy needs to be added for http server events to properly shutdown.
server = require('http-shutdown')(server);

// Listen on a port and start taking requests.
server.listen(3000);

// Sometime later... shutdown the server.
server.shutdown(function(err) {
	if (err) {
		return console.log('shutdown failed', err.message);
	}
	console.log('Everything is cleanly shutdown.');
});
```

The second is implicitly adding prototype functionality to the `Server` object:

```javascript
// .extend adds a .withShutdown prototype method to the Server object
require('http-shutdown').extend();

var server = require('http').createServer(function(req, res) {
  res.end('God job!');
}).withShutdown(); // <-- Easy to chain. Returns the Server object

// Sometime later, shutdown the server.
server.shutdown(function(err) {
	if (err) {
		return console.log('shutdown failed', err.message);
	}
  console.log('Everything is cleanly shutdown.');
});
```

## Test
```bash
$ npm test
```

[npm-image]: https://img.shields.io/npm/v/http-shutdown.svg?style=flat-square
[npm-url]: https://npmjs.org/package/http-shutdown
[travis-image]: https://img.shields.io/travis/thedillonb/http-shutdown.svg?style=flat-square
[travis-url]: https://travis-ci.org/thedillonb/http-shutdown
[coveralls-image]: https://img.shields.io/coveralls/thedillonb/http-shutdown.svg?style=flat-square
[coveralls-url]: https://coveralls.io/r/thedillonb/http-shutdown