CODEWITHSUNDEEP
javascriptnode.jsexpress
Opalium
Opalium

Reputation: 141

Restart an Express.js server with the same port

I have a Node.js app that uses Express.js to listen for connections. The code is something like so:

const express = require("express");
var server = express();
server.get("/test", (req, res) => testResponse(req, res));
server.listen(9001);
console.info("Server is listening to port 9001.");

I'd like to implement a way to restart the server without having to restart the whole app. However, I can't seem to properly shut down the server and free the port. Here's what I tried:

server.close();
console.info("Server closed. Restarting.");

var server = express();
server.get("/test", (req, res) => testResponse(req, res));
server.listen(9001);
console.info("Server is listening to port 9001.");

As soon as I run this, I get

Error: listen EADDRINUSE :::9001

What would be the correct way to do this?

Cheers.

Upvotes: 4

Views: 9184

Answers (2)

kgangadhar
kgangadhar

Reputation: 5088

As of Express 3, the app.close() method seems to have disappeared, which means Express users have no means of gracefully stopping an application. Express is really a listener to http request events which means you can do this:

const express = require("express");
var server = express();
server.get("/test", (req, res) => testResponse(req, res));
var app = server.listen(9001, function () {
    console.log('Listening :)');
    app.close(function () {
        console.info("Server closed. Restarting.");
        var server = express();
        server.get("/test", (req, res) => testResponse(req, res));
        server.listen(9001);
        console.info("Server is listening to port 9001.");
    });
});;
console.info("Server is listening to port 9001.");

For more on this you can refer hardening nodejs for production

Upvotes: 0

zero298
zero298

Reputation: 26878

server.close() is asynchronous and takes a callback. Try waiting until the server is actually closed before starting a new one:

server.close(()=>{

    console.info("Server closed. Restarting.");

    var server = express();
    server.get("/test", (req, res) => testResponse(req, res));
    server.listen(9001);
    console.info("Server is listening to port 9001.");

});

Upvotes: 2

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