What is the SIMPLEST method to deploy and update the VPCs in each account?
Create an AWS CloudFormation template defines the VPC. Log in to the AWS Management Console under each account and create a stack from the template.
Create a shell script that configures the VPC using the AWS CLI. Provide a list of accounts to the script from a text file, then create the VPC in every account in the list.
Create an AWS Lambda function that configures the VPC. Store the account information in Amazon DynamoDB, grant Lambda access to the DynamoDB table, then create the VPC in every account in the list.
Create an AWS CloudFormation template that defines the VPC. Create an AWS CloudFormation StackSet based on the template, then deploy the template to all accounts using the stack set.
Explanations:
This approach requires manual intervention to create the CloudFormation stack in each account, which is not scalable or automated for managing multiple accounts.
A shell script can automate the VPC creation but does not provide a centralized and consistent way to manage updates across multiple accounts, especially for future changes.
While Lambda can automate the creation of a VPC, this solution involves complex management of account information in DynamoDB, making it more complicated than necessary.
AWS CloudFormation StackSets allow for automated deployment and management of CloudFormation templates across multiple accounts, making it the simplest and most scalable solution.
I design that the answer is:
Create an AWS CloudFormation template that defines the VPC. Create an AWS CloudFormation StackSet based on the template, then deploy the template to all accounts using the stack set.