Be DRY; use terraform-aws-util//modules/get-subnets

Author: JonRoma

.github/workflows/terraform.yml

@@ -20,8 +20,6 @@ jobs:
 
       - name: terraform setup
         uses: hashicorp/setup-terraform@v1
-        with:
-          terraform_version: 0.12.29
       #   cli_config_credentials_token: ${{ secrets.TF_API_TOKEN }}
 
 #     TODO: This step duplicates work done by the Makefile.

Dockerfile

@@ -1,4 +1,4 @@
-FROM hashicorp/terraform:0.12
+FROM hashicorp/terraform
 
 RUN apk add make
 

README.md

@@ -74,7 +74,7 @@ module "service_name" {
 
   network_configuration = {
     assign_public_ip = true
-    tier             = "public"
+    subnet_type      = "public"
     vpc              = "my-vpc"
   }
 }
@@ -92,8 +92,8 @@ module "service_name" {
   }
 
   network_configuration = {
-    tier = "nat"
-    vpc  = "my-vpc"
+    subnet_id = "campus"
+    vpc       = "my-vpc"
   }
 }
 ```
@@ -473,12 +473,12 @@ EC2 Container Service Developer Guide.](https://docs.aws.amazon.com/AmazonECS/la
 
 A `network_configuration` block supports the following:
 
-* `tier` - (Optional) A subnet tier tag (e.g., public, private, nat) to determine subnets to be associated with the task orservice.
+* `subnet_type` - (Required) Subnet type (e.g., 'campus', 'private', 'public') for resource placement.
 
 * `vpc` - (Optional) The name of the virtual private cloud to be associated with the task or
-service. **NOTE:** Required when using `tier`.
+service. **NOTE:** Required when using `subnet_type`.
 
-* `subnets` - (Required) The subnet IDs to associated with the task or service. **NOTE:** Optional when using `tier`.
+* `subnets` - (Required) The subnet IDs to associated with the task or service. **NOTE:** Optional when using `subnet_type`.
 
 * `security_groups` - (Optional) The security groups associated with
 the task or service. If you do not specify a security group, the
@@ -503,9 +503,9 @@ For more information, see [Task Networking](https://docs.aws.amazon.com/AmazonEC
 > Note: `network_configuration` is only supported when `network_mode`
 > is `aws_vpc`.
 >
-> Note: The `tier` and `subnet` attributes can be used together. In this case the subnets
+> Note: The `subnet_type` and `subnet` attributes can be used together. In this case the subnets
 > to be associated with the service consist of the union of the subnets defined explicitly
-> in `subnet` and derived from `tier` and `vpc`.
+> in `subnet` and derived from `subnet_type` and `vpc`.
 
 `service_discovery`
 -----------------

data.tf

@@ -1,6 +1,6 @@
 locals {
   all_subnets = distinct(
-    concat(flatten(data.aws_subnet_ids.selected.*.ids), local.subnets),
+    concat(flatten(module.get-subnets.subnets.ids), local.subnets),
   )
   lb_vpc_id     = element(concat(data.aws_lb.selected.*.vpc_id, [""]), 0)
   subnet_vpc_id = element(concat(data.aws_subnet.selected.*.vpc_id, [""]), 0)
@@ -12,6 +12,13 @@ data "aws_ecs_cluster" "selected" {
   cluster_name = var.cluster
 }
 
+
+module "get-subnets" {
+  source = "github.com/techservicesillinois/terraform-aws-util//modules/get-subnets?ref=v3.0.4"
+
+  subnet_type = local.subnet_type
+  vpc         = local.vpc
+}
 ## LB data sources
 
 data "aws_lb" "selected" {
@@ -41,20 +48,3 @@ data "aws_subnet" "selected" {
   count = length(var.network_configuration) > 0 ? 1 : 0
   id    = local.all_subnets[0]
 }
-
-data "aws_vpc" "selected" {
-  count = local.tier != "" ? 1 : 0
-
-  tags = {
-    Name = local.vpc
-  }
-}
-
-data "aws_subnet_ids" "selected" {
-  count  = local.tier != "" ? 1 : 0
-  vpc_id = data.aws_vpc.selected[0].id
-
-  tags = {
-    Tier = local.tier
-  }
-}

locals.tf

@@ -62,9 +62,9 @@ locals {
       lookup(var.network_configuration, "security_group_names", ""),
     ),
   )
-  subnets = compact(split(" ", lookup(var.network_configuration, "subnets", "")))
-  tier    = lookup(var.network_configuration, "tier", "")
-  vpc     = lookup(var.network_configuration, "vpc", "")
+  subnets     = compact(split(" ", lookup(var.network_configuration, "subnets", "")))
+  subnet_type = lookup(var.network_configuration, "subnet_type", "")
+  vpc         = lookup(var.network_configuration, "vpc", "")
 }
 
 locals {

versions.tf

@@ -1,3 +1,3 @@
 terraform {
-  required_version = ">= 0.12"
+  required_version = ">= 1.1"
 }