How to properly close Node.js Express server?

Question

I need to close server after getting callback from /auth/github/callback url. With usual HTTP API closing server is currently supporting with server.close([callback]) API function, but with node-express server i’m getting TypeError: Object function app(req, res){ app.handle(req, res); } has no method 'close' error. And I don't know how to find information to solve this problem.
How should I close express server?

NodeJS configuration notes:

$ node --version
v0.8.17
$ npm --version
1.2.0
$ npm view express version
3.0.6

Actual application code:

var app = express();

// configure Express
app.configure(function() {
    // … configuration
});

app.get(
    '/auth/github/callback',
    passport.authenticate('github', { failureRedirect: '/login' }),
    function(req, res) {
        res.redirect('/');

        setTimeout(function () {
            app.close();
            // TypeError: Object function app(req, res){ app.handle(req, res); } has no method 'close'
        }, 3000)
    }
);

app.listen('http://localhost:5000/');

Also, I have found ‘nodejs express close…’ but I don't sure if I can use it with code I have: var app = express();.

I'm starting a express into a unit test. In this scope, close() does not stop the server — JRichardsz, Jun 06 '21 at 00:31
@JRichardsz See https://stackoverflow.com/a/21739334/1057730 — Vladimir Starkov, Jun 08 '21 at 08:47
I think the problem is in due to mocha. I will prepare a minimal runnable sample. My workaround is process.exit(0) — JRichardsz, Jun 08 '21 at 14:12
@JRichardsz it is not mocha. process.exit(0) to workaround, is what axe is to headache. — Vladimir Starkov, Jun 15 '21 at 09:19
What i wanted to say is that in my case I'm using a express insise of mocha test. In this particular scenario, close() don't works. Just process.exit(0) works :( — JRichardsz, Jun 15 '21 at 13:37

score 146 · Accepted Answer · edited Nov 22 '22 at 02:12

146

app.listen() returns http.Server. You should invoke close() on that instance and not on app instance.

Ex.

app.get(
    '/auth/github/callback',
    passport.authenticate('github', { failureRedirect: '/login' }),
    function(req, res) {
        res.redirect('/');

        setTimeout(function () {
            server.close();
            // ^^^^^^^^^^^
        }, 3000)
    }
);

var server = app.listen('http://localhost:5000/');
// ^^^^^^^^^^

You can inspect sources: /node_modules/express/lib/application.js

edited Nov 22 '22 at 02:12

ggorlen

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answered Jan 25 '13 at 05:59

Vladimir Kuznetsov

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7

Strange, it is not closing if I access some route. – Uday Hiwarale Jul 18 '16 at 22:37
1

@Uday, I also experienced this. I found out that my browser had an HTTP1.1 persistant connection open, so when I pressed F5 it appeared as though the server didn't close. If you try a different browser you will see the server socket is not running. – Rick Velde Dec 15 '16 at 22:41
1

That was my mistake, I was calling close on `app` instead of `server`. Saved my day. Many thanks – Edison Spencer Dec 06 '19 at 12:05
why the Timeout? – João Pimentel Ferreira Jul 15 '21 at 12:39
@JoãoPimentelFerreira it seems that Vladimir simply followed the example OP gave where they close after 3 seconds – Oleg Valter is with Ukraine Jul 15 '21 at 12:40

score 61 · Answer 2 · edited Oct 09 '21 at 18:53

61

In express v3 they removed this function.

You can still achieve the same by assigning the result of app.listen() function and apply close on it:

var server = app.listen(3000);
server.close((err) => {
  console.log('server closed')
  process.exit(err ? 1 : 0)
})

https://github.com/visionmedia/express/issues/1366

edited Oct 09 '21 at 18:53

João Pimentel Ferreira

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answered Feb 12 '14 at 20:52

Michael

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Use something like https://github.com/gajus/http-terminator to ensure termination of the server in case there are persistent connections or requests not producing a response. – Gajus Jan 20 '20 at 03:16
short and simple – krupesh Anadkat May 28 '20 at 12:56

score 14 · Answer 3 · edited Oct 09 '21 at 18:54

14

If any error occurs in your express app then you must have to close the server and you can do that like below-

var app = express();
var server = app.listen(process.env.PORT || 5000)

If any error occurs then our application will get a signal named SIGTERM. You can read more SIGTERM here - https://www.gnu.org/software/libc/manual/html_node/Termination-Signals.html

process.on('SIGTERM', () => {
  console.info('SIGTERM signal received.');
  console.log('Closing http server.');
  server.close((err) => {
    console.log('Http server closed.');
    process.exit(err ? 1 : 0);
  });
});

edited Oct 09 '21 at 18:54

João Pimentel Ferreira

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answered Jul 01 '19 at 12:05

Neha Sharma

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1

sorry, its not relevant. Question is about manual server shutdown and not about error handling – Vladimir Starkov Jul 01 '19 at 15:56
are you sure `server.close` has a callback? I don't see it in the documentation – João Pimentel Ferreira Jul 15 '21 at 12:40
@JoãoPimentelFerreira - yup, it's [certainly there](https://nodejs.org/dist/latest-v16.x/docs/api/http.html#http_server_close_callback) – Oleg Valter is with Ukraine Jul 15 '21 at 12:43
@OlegValter thanks but I read that expressJs server does not inherit anymore from nodejs http-server – João Pimentel Ferreira Jul 15 '21 at 12:48
1

@JoãoPimentelFerreira last time I checked, `app.listen` call still does: "The app.listen() method returns an http.Server object and (for HTTP) is a convenience method for the following" – Oleg Valter is with Ukraine Jul 15 '21 at 12:58

score 5 · Answer 4 · answered Jan 20 '20 at 03:15

I have answered a variation of "how to terminate a HTTP server" many times on different node.js support channels. Unfortunately, I couldn't recommend any of the existing libraries because they are lacking in one or another way. I have since put together a package that (I believe) is handling all the cases expected of graceful express.js HTTP(S) server termination.

https://github.com/gajus/http-terminator

The main benefit of http-terminator is that:

it does not monkey-patch Node.js API
it immediately destroys all sockets without an attached HTTP request
it allows graceful timeout to sockets with ongoing HTTP requests
it properly handles HTTPS connections
it informs connections using keep-alive that server is shutting down by setting a connection: close header
it does not terminate the Node.js process

13

It remains a valid question. – Gajus Jan 23 '20 at 07:13

score 2 · Answer 5 · answered Jun 03 '22 at 13:04

calling server.close does the job

server.close((err) => {
  console.log('server closed')
  process.exit(err ? 1 : 0)
})

also it is good to listen for system(user) signals and shutdown gracefully on them too, for that you should listen on both SIGTERM and SIGINT

const port = process.env.PORT || 5000;
const server = app.listen(port);
console.log(`listening on port:${port}`);
for (let signal of ["SIGTERM", "SIGINT"])
    process.on(signal, () => {
        console.info(`${signal} signal received.`);
        console.log("Closing http server.");
        server.close((err) => {
            console.log("Http server closed.");
            process.exit(err ? 1 : 0);
        });
    });

João Pimentel Ferreira · Answer 6 · 2023-05-16T09:16:35.093

2

Old question but now Node v18.2.0 introduced server.closeAllConnections(). It should be noted that server.close never runs its callback when the browser sends the request Connection: keep-alive, because server.close only stops the server from accepting new connections, it does not close old connections.

Before Node v18.2.0 I tackled this problem by waiting 5 seconds for the server to shutdown, after which it would force exit.

This code encompasses both situations

process.on('SIGINT', gracefulShutdown)
process.on('SIGTERM', gracefulShutdown)

function gracefulShutdown (signal) {
  if (signal) console.log(`\nReceived signal ${signal}`)
  console.log('Gracefully closing http server')

  try {
    server.close(function (err) {
      if (err) {
        console.error('There was an error', err.message)
        process.exit(1)
      } else {
        console.log('http server closed successfully. Exiting!')
        process.exit(0)
      }
    })

    // closeAllConnections() is only available from Node v18.02
    if (server.closeAllConnections) server.closeAllConnections()
    else setTimeout(() => process.exit(0), 5000)

  } catch (err) {
    console.error('There was an error', err.message)
    setTimeout(() => process.exit(1), 500)
  }
}

edited May 16 '23 at 09:16

answered Sep 05 '22 at 19:20

João Pimentel Ferreira

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i think closeAllConnections() has to be called AFTER calling close(). – Welcor May 14 '23 at 17:00
@Welcor why do you say that? Shouldn't we close connections before closing the server? – João Pimentel Ferreira May 15 '23 at 10:08
close() stops accepting new connections but will keep all existing connections. As long as connections exists it will not close. I think, when you call closeAllConnections() before close() there is a possibility that a connection is created between closeAll..() and close(). Then close() will not close until this connection closes itself. – Welcor May 15 '23 at 19:18
@Welcor I don't think so, if you call `close` without previously calling `closeAllConnections`, if you have a pending connection (for example waiting for a response), `server` will never trigger its callback. That's why before node 18 you have to force exit after a timeout. – João Pimentel Ferreira May 15 '23 at 20:01
the pending connection will be closed by closeAllConnections() after the close(). this then triggers the close() callback. timeline: close() -> closeAllConnections() -> close() callback called. – Welcor May 15 '23 at 20:36

tanguy_k · Answer 7 · 2023-01-01T18:13:43.333

0

Most answers call process.exit(), I don't think this is a good idea. You probably need to perform some teardown, also it's simply not needed.

const server = app.listen(port);

server.on('close', () => {
  // Perform some teardown, for example with Knex.js: knex.destroy()
});

// FYI Docker "stop" sends SIGTERM
// If SIGTERM is not catched, Docker is forced to kill the container after ~10s
// and this provokes an exit code 137 instead of 0 (success)
process.on('SIGTERM', () => server.close());

Check Express.js 4.x documentation: https://expressjs.com/en/advanced/healthcheck-graceful-shutdown.html#graceful-shutdown

edited Jan 01 '23 at 18:13

answered Jan 01 '23 at 18:06

tanguy_k

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I think you missed the 1st sentence in the question: "I need to close server after getting callback from /auth/github/callback url." – Vladimir Starkov Feb 14 '23 at 12:19

How to properly close Node.js Express server?

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