MEAN STACK

Demonstration of how to implement a simple book register web form using a MEAN stack.

Happy learning!

MEAN STACK

MEAN STACK is a combination of the following components:

• MongoDB document based NoSQL database program that stores and allows us to retreive data.

• Express.js back-end application framework that will make requests to the database for reads and writes (RESTful APIs).

• AngularJS structural framework for dynamic web applications.

• Node.js JavaScript runtime environment that accepts requests and displays results to the end user.

Launching your EC2 Instance

So, first we need to create an account on AWS. Then we need to sign into our AWS account and setup a new Elastic Compute Cloud (EC2) instance, "mean-stack" can be our new EC2 instance's name.

To do that we click on the search box and type "EC2". Then we click on where it says "EC2 Virtual Servers in the Cloud":

We can setup an EC2 free-tier instance such as the: "t2.micro family with Ubuntu Server 20.04 LTS HV". To do so we click on "Launch Instance" and select the previously mentioned free-tier instance. We can see steps of the process on the images listed below:

• As we are setting up our new instance, we give a name to our private key using a ".pem" file format and download it from AWS.

• We choose a new security group with default settings. Keep in mind that these settings can be changed in the future. Then we allow access from all IP addresses, this is ideal for testing purposes only.

• Once our instance is up and running, we connect to it using our terminal.

NOTE: .pem stands for "Privacy Enhanced Mail" which a file format that supports encryption, digital signatures and digital certificates as well as private and public key methods.

NOTE: Ubuntu is one of many Linux distributions

Connecting to your EC2 Instance

If you have macOS you can just press 'cmd spacebar' and type in 'terminal' to open the terminal.

If you have Windows you will need to download an SSH client such as "Putty"or "MobaXterm". You can download any of these by typing "Putty"or "MobaXterm" on Google.

The following website includes information about how to connect to your EC2 instance once you have downloaded an SSH client on Windows:

https://www.clickittech.com/aws/connect-ec2-instance-using-ssh/

NOTE: You can get your ipv4 (public-ip address) from AWS:

We can see on the images below how to SSH into our EC2 instance using macOS:

• We start our instance by selecting our instance and the clicking on "Instance State" then we click "Start instance".

• Once our instance is up and running, we select it and click on connect.

• We click on the 'SSH client' tab and then copy the SSH command that is listed under "Example:"

Once we have copied the SSH command, we change directories to our Downloads folder because that is where our private key is located. So on our terminal we run:

cd Downloads

We paste the SSH command into our terminal, then we input yes. If this is the first time that you are doing this, congratulations!! You have just launched your first server on the cloud!

NOTE: Here is an explanation of the SSH command:

ssh -i "web-server.pem" ubuntu@18.191.193.88

• ssh: Means 'secure shell' and it is a protocol used to securely connect to a remote server/system.

• -i: Selects a file from which the identity (private key) for public key authentication is read.

• web-server: The name of your .pem file.

• .pem: is a file format for encoding keys and certificates. You downloaded the .pem file from AWS when you launched your EC2 instance. The .pem file contains a public key-pair. Downloading a .pem file is a one time download, so you need to make sure that you do not to delete or lose it in the future since you will need the .pem file to connect remotely to your instance. You also need to know the directory where your .pem file is located at.

NOTE: a public key-pair involves a public key and a private key which are associated with an entity that needs to authenticate its identity electronically or to sign or encrypt data. Each public key is published and the corresponding private key is kept secret. Data that is encrypted with the public key can be decrypted only with the corresponding private key.

• ubuntu: The Linux distribution of your EC2 instance.

• 18.191.193.88: Is the public IP or IPv4 of your EC2 instance. It is the underlying technology that makes it possible for us to connect our devices on the internet.

NOTE: You can either use your EC2 instance's public ip address or DNS name.

Updating your EC2 Instance

So, once we SSH into our EC2 instance we update and upgrade the list of available packages:

sudo apt update

sudo apt upgrade

Installing Node.js

We will be using Node.js to set up the Express routes and AngularJS controllers so we run:

sudo apt install nodejs -y

Installing MongoDB

MongoDB stores our data in JSON-like documents.

In this case we will be adding book records to our MongoDB that contain the following: book name, isbn number, author, and number of pages.

To install MongoDB we use:

sudo apt install mongodb -y

Then we start the server:

sudo service mongodb start

We verify that the service is running:

sudo systemctl status mongodb

Installing Node Package Manager

sudo apt install -y npm

We also need to install the ‘body-parser’ package to help us process JSON files passed in requests to the server:

sudo npm install body-parser

We create a folder named 'Books':

mkdir Books

Then we change directories:

cd Books

In our Books directory, we initialize the npm project:

npm init

In our root directory 'Books' we create a file named 'server.js':

vi server.js

We input or paste the following code in it:

Installing Express and Setting Up Routes to the Server

Express is a minimal and flexible Node.js web application framework that provides features for web and mobile applications. We will use Express to pass book information to and from our MongoDB database.

We also will use Mongoose package which provides a straight-forward, schema-based solution to model our application data. We will use Mongoose to establish a schema for the database to store data of our book register.

So we run:

sudo npm install express mongoose

In our 'Books' folder, we create a folder named apps and we change directories to the apps folder:

mkdir apps && cd apps

Then we create a file named routes.js:

vi routes.js

We input or paste the following code into routes.js:

In the 'apps' folder, we create a folder named models:

mkdir models && cd models

In the models folder we create a file named book.js:

mkdir book.js

We input or paste the following code into book.js:

Accessing Routes with AngularJS

AngularJS provides a web framework for creating dynamic views in our web applications. In this tutorial, we will use AngularJS to connect our web page with Express and perform actions on our book register.

So we change the directory back to 'Books':

cd ../..

And create a folder named 'public':

mkdir public

Then we add a file to it named 'script.js'

vi script.js

We input or paste the following code into our script.js file:

In our public folder, we also create a file named 'index.html'

vi index.html

We input or paste the following code into it:

NOTE: The identation of the code does not have to be indented as it appears on the picture. The identation can be way simpler and more practical. However, my vi text-editor formatted it that way when I pasted it. (I also tried it with vim but it formatted it the same way)

Then we change the directory back to 'Books':

cd ..

Starting the Node Server

So, after changing directories to 'Books' we start our server by running:

node server.js

The server is now up and running, we can connect it via port 3300.

Let's access it from our browser. However, before doing that, we will need to open a TCP on port 3300 in our AWS Web Console for our EC2 instance and allow access from anywhere. (not ideal for security reasons, but it is good for testing purposes)

Ultimately, we access our book register web application from the internet with our browser using our EC2 instance's Public IP address or Public DNS name. 'http://localhost:3300'.

NOTE: Replace 'localhost' with your EC2 instance public-ipv4-address.