Start node.js express server as a service

Question

I'm currently preparing a react web app for production have set up a centos machine to host the app using node.js and express. I'd like to automate the starting of the express server.

My file structure is as follows:

/opt/
  |__ /express/
       |__ /node_modules/~
       |__ express.js
       |__ /public/
            |__ bundle.js
            |__ styles.css
            |__ index.html

Once the react web app is developed locally, it's packaged into a distribution and then moved into the public folder as seen above. express.js then starts the server and serves the page:

var path = require('path');
var express = require('express');
var app = express();
var port = 8000;

app.use(express.static('./public'));
app.get('*', (req, res) => {
    res.sendfile(path.resolve(__dirname, 'public/index.html'));
});
app.listen(port, () => {
    console.log('server running on port ' + port);
});

This works fine but requires me to manually start the server every time. I would like now to run express.js as an operating system level service so that its persistent and automatically starts up on boot/restart.

Ideally I would like this to be managed purely by the OS and not us any other npm packages.

How can this be done?

Answer 1

You probably want to use https://en.wikipedia.org/wiki/Systemd

TLDR:

Create the file /lib/systemd/system/<NiceReactApp>.service

Now put the service information in the file, replace what is in between <> with your values.

[Unit]
Description=<a nice react web app>

[Service]
Type=simple
User=<TheAccountForThisReactApp>
ExecStart=/usr/bin/node /home/<TheAccountForThisReactApp>/opt/express/express.js
Restart=on-failure

[Install]
WantedBy=multi-user.target

sudo systemctl daemon-reload

sudo systemctl start <NiceReactApp>

If you're using nvm to manage your node packages you will want to change the first argument for ExecStart to where you node package is.

Answer 2

You can use pm2 module to get the application to launch on system boot/restart, also it restarts the app automatically if it crashes or is killed to keep the server always available. TLDR:

Install pm2:

npm install pm2 -g

Start the app forever:

pm2 start app.js

Get the application to launch on system boot/restart:

pm2 startup systemd

Answer 3

I use forever

npm install -g forever

sudo forever-service install --script ./bin/www myapp

sudo service myapp