import_state_tagger.tf

# Pull in existing VPC
data "aws_vpc" "selected" {
  id = var.vpc_id
}

# Subnet ids data source lookup allows multiple subnets to be provided
data "aws_subnet_ids" "private" {
  vpc_id = data.aws_vpc.selected.id

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

# Pull in all private subnet CIDR Blocks for a for_each as this data source allows only 1 subnet
data "aws_subnet" "private_subnet_cidr" {
  for_each = data.aws_subnet_ids.*.id
  id       = each.value
}

# Try to attach tags to all those subnet ID's. 
resource "aws_subnet" "private_subnet_tags" {
  for_each   = values(data.aws_subnet.private_subnet_cidr).*.cidr_block
  vpc_id     = data.aws_vpc.selected.id
  cidr_block = each.value

  tags = {
    "PRIVATETAGONE" = "HELLOWORLD"
    "PRIVATETAGTWO" = "HELLOWORLD"
  }
}

null_resource_tagger.tf

variable "tag_map" {
  default = {
    "PRIVATETAGONE" = "HELLOWORLD"
    "PRIVATETAGTWO" = "HELLOWORLD"
  }
}

locals {
  formatted_tags = join(" ", formatlist("Key='%s',Value='%s'", keys(var.tag_map), values(var.tag_map)))
}

# Pull in existing VPC
data "aws_vpc" "selected" {
  id = var.vpc_id
}

# Subnet ids data source lookup allows multiple subnets to be provided
data "aws_subnet_ids" "private" {
  vpc_id = data.aws_vpc.selected.id

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


# Use this option if you dont want to import state
resource "null_resource" "tagger" {
  for_each = data.aws_subnet_ids.private.*.id
  triggers = {
    tags = local.formatted_tags
    }
  provisioner "local-exec" {
    command = "aws ec2 create-tags --resources ${each.value} --tags ${local.formatted_tags}"
  }

  provisioner "local-exec" {
    when    = "destroy"
    command = "aws ec2 delete-tags --resources ${each.value} --tags ${local.formatted_tags}"
  }
}

Coming across 2 reference issues, but I'm digging into to see what I can find:

Error: Invalid reference

  on main.tf line 69, in resource "null_resource" "tagger":
  69:   for_each = data.aws_subnet_ids.*.id

The "data" object must be followed by two attribute names: the data source
type and the resource name.


Error: Incorrect attribute value type

  on main.tf line 70, in resource "null_resource" "tagger":
  70:   triggers = local.formatted_tags

Sry small syntax errors, updated