CloudFormation

• StackSets

  • Create, update, or delete stacks across multiple accounts and regions with a single operation

  • Same CloudFormation templates to be used, on different multiple/Different AWS accounts use StackSets

• CloudFormation templates

  • Metadata

  • Parameters

    1. It’s like variables declaration, contains values to pass to your template at runtime

  • Rules

  • Mappings

    1. set values based on a region

    2. use the Fn::FindInMap intrinsic function to retrieve values in a map

  • Conditions

  • Transform

  • Resources

    1. This is the ONLY mandatory field

    2. AWS resources that you want to include in the stack, Ex: EC2 instance or S3 bucket.

  • Outputs

    1. output values that you can import into other stacks

    2. View on the AWS CloudFormation console.

• Helper scripts

  • cfn-init: install packages, create files, and start services.

  • cfn-signal: synchronize other resources in the stack when the prerequisite resource or application is ready.

  • cfn-get-metadata: retrieve metadata for a resource or path to a specific key.

  • cfn-hup: Use to check for updates to metadata and execute custom hooks when changes are detected.

• Cross Stack Reference

  • Helps you to simplify cloud formation templates

  • !ImportValue

  • write small scripts for creating SG , subnets, and call them in another script