modify existing AWS VPC using terraform

Question

I want to modify existing VPC by removing the black holed routetabes and update it with new route tables - the routetables i want to modify are created manually (not by the terraform). is that possible in terraform? any sample templates i can refer? Many Thanks, Deepak

Answer 1

If you have existing infrastructure in AWS and you want to manage it with Terraform, you need to use the Terraform import command.

First, write the Terraform code that matches the route tables you already have. For example:

resource "aws_route_table" "example" {
  vpc_id = "${aws_vpc.main.id}"
}

Next, look up the route table ID of the existing route table, and use the import command to have Terraform link the Terraform code above to that existing table:

terraform import aws_route_table.example rtb-12345678

You can also try out a tool like Terraforming which can generate the code and import the state automatically.