NJOKU SAMSON EBERE

Posted on Feb 3, 2020 • Edited on May 12, 2020

Setting Up a Simple, Secure and Robust Node JS Server

#javascript #node #express #api

In this tutorial, we will be setting up a simple server - first, without express and then with express.

I assume that you already understand the theory behind Node.js, express and nodemon so we will just go straight to practicals.

Install Node.js and NPM
Check if installation was successful
Create a Node server without Express
Test our server
Send Back a Response From our Server
Create a Node Server With Express
Secure your server. Make it Future-proof
Conclusion

Install Node.js and NPM (if you have not done so)

Go to node.js website
Click on the recommended download button

When the download is complete, install node.js using the downloaded .exe file (It follows normal installation process).

Check if installation was successful

Go to your terminal/command prompt (run as administrator if possible)
Type in each of the following and hit Enter button

    node -v

    npm -v

Your output should be similar to the image below.

The version maybe different but that is OK.

Create a Node server without Express

For the rest of this tutorial, I will be using VS code editor. You can use whatever editor you choose.

Let's start by creating a project directory. Start a terminal and type the following to create a directory and open it.

  mkdir server-tutorial
  cd server-tutorial

I named my project directory: server-tutorial (you can name yours as you please).

In the terminal, type in the following: npm init. Hit the Enter button for all prompts. When completed, you should have a package.json file seated in your project directory.

The package.json file is just a file with all the details of your project. You don't have to open it.

Create a file index.js
In the file, require the HTTP module like so:

    const http = require('http');

Call the createServer() method on it and assign it to a constant like so

    const server = http.createServer();

Call the listen() method on the server constant like so

    server.listen();

Give it a port to listen to. Now this could be any free port but we will be using port 3000 which is the conventional port. So we have

    const http = require('http');

    const server = http.createServer();

    server.listen(3000);

Basically, that is all you need do to create a server.

Test our server.

In your terminal (should be in the project directory), type node index.js and hit the Enter button.
Open a new tab in postman or any web browser and in the address bar, type http://localhost:3000/ and hit the Enter button. (I will be using postman because of it extended functionalities outside the box)

You will notice that your browser or postman keep loading indefinitely like so

Yaye... That is fine. Our Server is up and running.

But it's boring already. We need to make the server talk to us.

Let's get to it immediately.

Send Back a Response From our Server

Back in our code, add the following to const server = http.createServer();

   (request, response) => {
      response.end('Hey! This is your server response!');
   }

So we now have:

  const http = require('http');

  const server = http.createServer((request, response) => {
    response.end('Hey! This is your server response!');
  });

server.listen(3000);

In a layman's term, the request object tells the server that we want something, the response object tells us what the server has to say about our request and the end() method terminates the communication with the server response.

Hopefully, that makes sense!

Now, test the server again following the steps we outlined above and your server should be talking to you. This is my output:

Feel free to change the string as you wish.

Use Control/Command + C to terminate the server and run node index to start the server again.

Looking Sharp! Right? All good...

Create a Node Server With Express

In this section, we want to make our lives easier using Express and Nodemon (node-mon or no-demon, pronounce as you wish).

In the terminal, install the following

  npm install express --save
  npm install nodemon --save-dev

Create a new file name it app.js or whatever suits you
In the file,

i. Require express like so

const express = require('express');

ii. Assign the express method to a constant like so

const app = express();

iii. Export the app constant to make it available for use in other files within the directory like so

module.exports = app;

So we have:

const express = require('express');

const app = express();



module.exports = app;

In the index.js file, require the app we exported a while ago like so

const app = require('./app');

Set the port using the app like so

app.set('port', 3000);

Replace the code in the http.createServer() method with just app like so

const server = http.createServer(app);

This directs all API management to the app.js file helping with separation of concerns.

So our index.js file now looks like this

const http = require('http');
const app = require('./app');

app.set('port', 3000);
const server = http.createServer(app);

server.listen(3000);

Back in our app.js file, since we have directed all API management to here, let's create an API to speak to us like before.

So before the module.exports = app, add the following

app.use((request, response) => {
   response.json({ message: 'Hey! This is your server response!' }); 
});

We now have:

const express = require('express');

const app = express();

app.use((request, response) => {
   response.json({ message: 'Hey! This is your server response!' }); 
});

module.exports = app;

Ahaaa... It's time to test our app

To test our app, we now type nodemon index in our terminal and hit the Enter button. This is my terminal

Do you notice that nodemon gives us details of execution in the terminal unlike node? That's the beauty of nodemon.

You can now go to postman or any browser and in the address bar, type http://localhost:3000/ and hit Enter button. See my output:

Walah!!! It's working.

Now more reason to use nodemon. Go to the app.js file and change the message string to any string on your choice, save and watch the terminal.

Wow... It automatically restarts the server. This was impossible with node. We had to restart the server ourselves.

Secure your server. Make it Future-proof

In the index.js file, replace all the code with the following:

const http = require('http');
const app = require('./app');

const normalizePort = val => {
  const port = parseInt(val, 10);

  if (isNaN(port)) {
    return val;
  }
  if (port >= 0) {
    return port;
  }
  return false;
};
const port = normalizePort(process.env.PORT || '3000');
app.set('port', port);

const errorHandler = error => {
  if (error.syscall !== 'listen') {
    throw error;
  }
  const address = server.address();
  const bind = typeof address === 'string' ? 'pipe ' + address : 'port: ' + port;
  switch (error.code) {
    case 'EACCES':
      console.error(bind + ' requires elevated privileges.');
      process.exit(1);
      break;
    case 'EADDRINUSE':
      console.error(bind + ' is already in use.');
      process.exit(1);
      break;
    default:
      throw error;
  }
};

const server = http.createServer(app);

server.on('error', errorHandler);
server.on('listening', () => {
  const address = server.address();
  const bind = typeof address === 'string' ? 'pipe ' + address : 'port ' + port;
  console.log('Listening on ' + bind);
});

server.listen(port);

process.env.PORT makes the app dynamic so that it can run any port assigned to it in the future when hosted on a live server

The normalizePort function returns a valid port, whether it is provided as a number or a string

The errorHandler function checks for various errors and handles them appropriately — it is then registered to the server

A listening event listener is also registered, logging the port or named pipe on which the server is running to the console

YooH! Our server is more secure and robust right now. Notice that nodemon also displays the port we are listening on now.

There you have it, a simple, secure and robust nodejs server

Conclusion

We have been able to learn how to create a server using just nodejs after which, we improved our server using express and nodemon.

All codes can be found here

EBEREGIT / server-tutorial

This is a tutorial was to teach how to create a simple, secure and robust nodejs server but we have expanded our scope to cloudinary and postgres

Up next, we will be looking at Image Upload to cloudinary using nodejs and express.

If you have questions, comments or suggestions, please drop them in the comment section.

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Thank You For Your Time.

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