Deploy An Apache Server On Public/Private Subnets On AWS

Introduction 

In this article, we are going to learn how we can deploy an apache server to both public and private subnets in AWS. so first we create two EC2 instances one if public and another one is a private EC2 instance and then we can deploy the apache server to these instances. First, we understand what is -

1. Public instance - can be accessible from the internet which means this can be accessed from anywhere.
2. Private instance - can not be accessible from the internet directly which means nobody can enter this subnet directly, generally, we put database servers in private instances and they can access via NAT gateway that resides in public subnets.to use the NAT gateway we require VPC
3. VPC - Virtual Private Cloud(VPC) is a secure, isolated private cloud hosted in a public cloud

Create a new VPC in AWS

Four steps to creating a new VPC,

• Create a VPC
• Create subnet
• Create an internet gateway
• Define route table

Create VPC  - Give the VPC name and choose the IPv4 CIDR block which basically used for allocating IP addresses

Create one public and private subnet

Public Subnet - Choose the name tag and select the VPC which we create in the last step and the availability zone,

Private Subnet - Similarly create one more subnet for the private subnet.

You can see both of the subnets shown in the list as of now these are only given names public and private, lets make them public and private subnets actually in the next steps 

 

Create Internet Gateway – this will allow the communication between VPC and the internet so give the appropriate name tag here. 

By Default, this internet gateway is not attached to any VPC

Let's attach the Internet Gateway to VPC by clicking on the Actions button and click to Attach to VPC. 

Select the VPC that we create at the start and click on it to attach the internet gateway

Now if you see in the list the VPC state changed to Attached and you can see the attached VPC id also.

Create and Define Route tables 

Route table basically contains a set of rules which determines how and where the packets are directed over the internet, so we create this route table different for both public and private subnets

This route table will determine the subnet is a public or private subnet.

Associates Subnets and define routes

We will associate the public subnet with the Internet Gateway and edit the route to associate this with a created internet gateway, similarly, we will associate the private subnet with the NAT gateway as it will not allow the communication over the internet directly.

Private Subnet Association –

Create Nat gateway to define route for private subnet, as with this only there is communication possible so you can give a NAT gateway name and you have to allocate elastic IP separately so this IP will help you in the communication and also select the public subnet via which communication is possible.

This time we associate this NAT gateway with the private subnets so now our both public and private subnets are ready and we already associate the route table with them

Time to create EC2 instance in both subnets

What is Amazon EC2 Instance

EC2 stands for Elastic compute cloud (Amazon EC2) and is one of the longest-running services on AWS. EC2 is just a virtual machine provisioned with a certain amount of CPU cores, memory, storage space, and networking. With this, anyone can install any type of operating system (OS) on it whether it's Linux or Windows.

Steps to create EC2 Instance

• Choose AMI
• Choose Instance Type
• Configure Instance
• Add Storage
• Add Tags
• Configure Security Group
• Review 

Public EC2 Instance –

The first step is to choose the AMI means machine type whether you going to select Windows, Linux, or any other Machine.

The next step is to choose our instance type which you select according to your requirement, I'm selecting here the free one t2.micro having 1 GB of memory and 1 CPU core

Select some basic configuration and choose the VPC network and the subnet which we already created in previous steps

The next step is to add the storage and I'm continuing with 8GIgs

Add some tags here for reference like this machine is associated with Public subnets so with the tags you get to know this is a public subnet.

In this step, you can define the security group, either you create the new one or select the existing security group and define the what kind of internet traffic reach your instance

Review all your instance settings and launch

Create and Download .Pem file

Next, Create a Private EC2 instance -

Similarly public instance we create one more instance for the private subnet, Choose the machine type here -

Then choose the instance type which defines the memory and CPU core of your machine.

Be careful here while creating another instance you need to select the private subnet and enable the auto-assign public IP for the private instance.

The next step is to add storage for this instance

Again these tags help you to differentiate your both machine so for my reference I add a tag of the private subnet.

This time I select the existing security group which already defines the rules to allow specific traffic to reach this instance.

Review and Launch the instance

Again you can select the existing key pair to avoid the multiple copies of key files.

The last step is to deploy the apache server on both the instances – We can also deploy the apache server at the time of creating the EC2 instance using user data, simply put the commands written below into user data in the EC2 instance configuration steps

First, we deploy the apache server to a Public EC2 instance -

You can copy the SSh command and run this to command prompt.

Commands to deploy apache server –

Sudo su

yum update -y
yum install -y httpd.x86_64
systemctl start httpd.service
systemctl enable httpd.service

Run the above commands one by one to deploy the apache server.

--- Sudo su

--- yum update -y

--- yum install -y httpd.x86_64

--- systemctl start httpd.service
--- systemctl enable httpd.service

use the curl command to hit the request on the localhost or you can hit this directly on the browser with the public IP address of the instance.

Access the apache server from the browser using the public IP of the EC2 instance.

Deploy Apache server on Private EC2 Instance 

For this first run the SSH command of a private instance via connecting to the public instance

Run Commands –

Sudo su

yum update -y
yum install -y httpd.x86_64
systemctl start httpd.service
systemctl enable httpd.service

--- Sudo su
--- yum update -y

--- yum install -y httpd.x86_64

--- systemctl start httpd.service
--- systemctl enable httpd.service

We can access the hosted file using the curl command in a private instance as we can't have direct access to this.

Summary

In this article, you learn about public and private subnets, VPC, and how to create EC2 instances different for both public and private subnets then we deploy an Apache server to these instances.

I hope you like this article and I would love to answer your queries in the comment section.

Stay safe and learn more!