AWS Autoscaling

• In EC2 instances we run our applications, as of now the approache which we are following is
  • take an OS based AMI and manually install the application
• As number of users start using this applications the resources will be exhausted, so we do horizontal scaling (i.e. increasing ec2 instances to share the workload)
• The problem with the above apporach is whenever ec2 instance is scaled, we need to install software in it.
• We need to figure out a way to create an AMI with application pre-installed
  
• Even if we have AMI with our application pre-installed, what can be done to give a new release.
• AWS has a way when a new version of AMI is released then
• To acheive this we need to create
  • AMI’s
  • Autoscaling Groups
  • Launch Templates
  • LoadBalancers
  • Target groups
  • Automate the AMI creation from ci/cd pipeline

Creating AMI

• Create an ubuntu 22.04 AMI based EC2 instance t2.micro and login in to the ec2 instance
• Install apache, php and stress

sudo apt update # not necessary on redhat
sudo apt install apache2 -y # sudo dnf install htttpd -y
sudo apt install stress -y
sudo apt install php libapache2-mod-php php-mysql -y # sudo dnf install php -y
sudo -i
echo "<?php phpinfo(); ?>" > /var/www/html/info.php

• navigate to http://<public-ip>/info.php
  
  
  
• Exercise:
  • Create the php info page on centos or redhat based linux instances Refer Here
  • Restart the ec2 instance and check if the apache is running or not
  • Understand what enabling the service in linux means
  • Enable the service in redhat instance
  • Restart the server and check apache should be running