Data.tf

Data file will store all the general dynamic blocks of your Terraform project. They are usually fetched using the cloud providers API.

They can be used with a prefix of data. i.e. data.aws_vpc

data.tf file

1. These configurations are done in the data.tf file.

Public subnet

1. Create data block type of aws_subnet_ids named public
   1. vpc_id should be var.vpc_id
   2. To get the correct public subnets we need to use filters and since our subnets have tag type: public/private we can utilise that.
      

      filter {
          name = "tag:type"
          values = ["public"]
        }
      

Private subnet

1. Create data block type of aws_subnet_ids named private
   1. vpc_id should be var.vpc_id
   2. To get the correct public subnets we need to use filters and since our subnets have tag type: public/private we can utilise that.

      filter {
          name = "tag:type"
          values = ["private"]
        }
      

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Answer

terraform/data.tf

data "aws_subnet_ids" "public" {
  vpc_id = var.vpc_id
  filter {
    name = "tag:type"
    values = ["public"]
  }
}

data "aws_subnet_ids" "private" {
  vpc_id = var.vpc_id
  filter {
    name = "tag:type"
    values = ["private"]
  }
}

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