Example - VPC Stack

This example shows a standard VPC setup with an IGW, two NAT gateways, two public and two private subnets and appropriate routes and NACLs.

Demonstrates the following

• CloudFormation Mappings are rendered as a locals block
• Inputs and outputs, along with Terraform.tfvars file holding current input values as read from CloudFormation
• Wide selection of intrinsics
  • !Ref is converted to input variable or resource reference expressions.
  • !FindInMap is converted to a reference to the appropriate value in locals block.
  • !Sub is converted to an interpolated string with implied reference expressions.
  • !Cidr and !Join are converted to corresponding Terraform built-in functions.
  • !GetAZs is converted to a reference to the aws_availability_zone data source.
  • !Ref AWS::Region is converted to a reference to the aws_region data source.
  • !Select applies an [index] to whatever list value is being referenced.
• What I am calling "merged resources", whereby there is a single Terraform resource that represents more than one CloudFormation resource are handled, e.g. aws_internet_gateway is a combination of AWS::EC2::InternetGateway and AWS::EC2::VPCGatewayAttachement

CloudFormation

CloudFormation to build the stack is here.

The stack was deployed with a stack name of test-vpc

Import run

This is the command to export test-vpc to Terraform in action...

Generated outputs

• main.tf
• terraform.tfvars