Using Fedora to quickly implement REST API with JavaScript

Fedora Workstation uses GNOME Shell by default and this one was mainly written in JavaScript.

JavaScript is famous as a language of front-end development but this time we‘ll show it‘s usage for back-end.

We‘ll implement a new API using the following technologies: JavaScript, Express and Fedora Workstation. A web browser is being used to call the service (eg. Firefox from the default Fedora WS distro).

Installing of necessary packages

Check: What we already have?

$ npm -v
$ node -v

Maybe we already have both of them installed and can skip the next 2 install steps.

Setup dnf repo

$ sudo dnf install -y gcc-c++ make
$ curl -sL https://rpm.nodesource.com/setup_12.x | sudo -E bash -

Install Node.js

$ sudo dnf install nodejs

A new simple service (low-code style)

Let‘s navigate to our working directory (‚work‘) and create a new directory for our new sample back-end app.

$ cd work
$ mkdir newApp
$ cd newApp
$ npx express-generator

## This one generates an application skeleton for us

$ npm i

## installs dependencies

Please mind the security warnings – never use this one for production.

Crack open the routes/users.js

Modify line #6 to:

res.send(data);

Insert this code block below var router …

let data = {
 '1':'Ann',
 '2': 'Bruno',
 '3': 'Celine'
 }

Save the modified file.

We modified a route and added a new variable data. This one could be declared as a const as we didn‘t modify it anywhere.

The result:

Running the service on your local Fedora workstation machine

$ npm start

Note: The application entry point is bin/www. You may want to change the port number there.

Calling our new service

Let‘s launch our Firefox browser and type-in:

http://localhost:3000/users

Output

It‘s also possible to leverage the Developer tools (F12 – Network tab – select the related GET request and look at the side bar response tab) to check the data.

Conclusion

Now we have got a service and and an unnecessary index accessible through localhost:3000/.

How to get quickly rid of this one?

1) remove ‚views‘ directory

2) remove ‚public‘ directory

3) remove routes/index.js

4) inside app.js file:

modify the line 37 to: res.status(err.status || 500).end();

remove the next line res.render(‘error’)

Restart the service

$ npm start