So we are launching an ecommerce store built on magento. We are looking to deploy it on Amazon EC2 instance using RDS as database service and using amazon auto-scaling and elastic load balancer to scale the application when needed.
What I don’t understand is this:
I have installed and configured my production magento enviorment on an EC2 instance (database is in RDS). This much is working fine. But now when I want to dynamically scale the number of instances
- how will I deploy the code on the dynamically generated instances each time?
- Will aws copy the whole instance assign it a new ip and spawn it as a
new instance or will I have to write some code to automate this
process? - Plus will it not be an overhead to pull code from git and deploy every time a new instance is spawned?
A detailed explanation or direction towards some resources on the topic will be greatly appreciated.
2
Answers
You do this in the AutoScalingGroup Launch Configuration. There is a UserData section in the LaunchConfiguration in CloudFormation where you would write a script that is ran when ever the ASG scales up and deploys a new instance.
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-as-launchconfig.html#cfn-as-launchconfig-userdata
This is the same as the UserData section in an EC2 Instance. You can use LifeCycle hooks that will tell the ASG not to put the EC2 instance into load until everything you want to have configured it set up.
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-as-lifecyclehook.html
I linked all CloudFormation pages, but you may be using some other CI/CD tool for deploying your infrastructure, but hopefully that gets you started.
To start, do check AWS CloudFormation. You will be creating templates to design how the infrastructure of your application works ~ infrastructure as code. With these templates in place, you can rollout an update to your infrastructure by pushing changes to your templates and/or to your application code.
In my current project, we have a github repository dedicated for these infrastructure templates and a separate repository for our application code. Create a pipeline for creating AWS resources that would rollout an updated to AWS every time you push to the repository on a specific branch.
containers
work, it would be better and will greatly supplement on your learning on how launching new version of application work. To begin, see docker, but feel free to check any resources at your disposalimage
that will become a container ~ from the docker documentation.