AWS CloudFormation

Infrastructure as Code

• Infrastructure as Code (IaC) is a way to provision and manage your infrastructure through code instead of through manual processes
• With IaC, you can create configuration files that contain your infrastructure specifications, which makes it easier to edit and distribute configurations.
• You provision the same environment every time in other account or region
• That code would be deployed and create/update/delete our infrastructure
• Version control is an important part of IaC, and your configuration files should be under source control just like any other software source code file.

What is CloudFormation

• You can use AWS CloudFormation to create AWS resources in an orderly and predictable fashion.
• Resources are written in text files using JSON or YAML format.
• The templates require a specific syntax and structure that depends on the types of resources being created and managed.
• A CloudFormation template is deployed into the AWS environment as a stack
• For example, within a CloudFormation template, you can create a set of:
  • One security group
  • Two EC2 instance using this security group
  • One S3 bucket
  • One load balancer (ELB) in front of these EC2

CloudFormation Concept

• When you use AWS CloudFormation, you work with templates and stacks
• Topics
  • Templates
  • Stacks
  • Change sets
• Templates
  • A CloudFormation template is a JSON or YAML formatted text file
  • CloudFormation uses these templates as blueprints for building your AWS resources
• Stacks
  • When you use CloudFormation, you manage related resources as a single unit called a stack.
  • You create, update, and delete a collection of resources by creating, updating, and deleting stacks.
• Change sets
  • If you need to make changes to the running resources in a stack, you update the stack.
  • Before making changes to your resources, you can generate a change set, which is a summary of your proposed changes.
  • Change sets allow you to see how your changes might impact your running resources, especially for critical resources, before implementing them.