feat(aws-ecs): use tags to find subnets

create-an-aws-ecs-byoc-app/components/ecs-service/alb.tf

@@ -3,7 +3,7 @@ module "ingress" {
 
   name                       = var.service_name
   vpc_id                     = var.vpc_id
-  subnets                    = local.public_subnet_id_list
+  subnets                    = data.aws_subnets.public.ids
   enable_deletion_protection = false
 
   security_group_ingress_rules = {

create-an-aws-ecs-byoc-app/components/ecs-service/data.tf

@@ -0,0 +1,13 @@
+data "aws_subnets" "private" {
+  filter {
+    name   = "visibility"
+    values = ["private"]
+  }
+}
+
+data "aws_subnets" "public" {
+  filter {
+    name   = "visibility"
+    values = ["public"]
+  }
+}

create-an-aws-ecs-byoc-app/components/ecs-service/outputs.tf

@@ -1,7 +1,7 @@
 output "private_subnet_ids" {
-  value = local.private_subnet_id_list
+  value = data.aws_subnets.private.ids
 }
 
 output "public_subnet_ids" {
-  value = local.public_subnet_id_list
+  value = data.aws_subnets.public.ids
 }

create-an-aws-ecs-byoc-app/components/ecs-service/service.tf

@@ -47,7 +47,7 @@ module "service" {
     }
   }
 
-  subnet_ids = local.private_subnet_id_list
+  subnet_ids = data.aws_subnets.private.ids
   security_group_rules = {
     ingress_http = {
       type                     = "ingress"

create-an-aws-ecs-byoc-app/components/ecs-service/variables.tf

@@ -1,8 +1,3 @@
-locals {
-  private_subnet_id_list = split(" ", trim(var.private_subnet_ids, "[]"))
-  public_subnet_id_list  = split(" ", trim(var.public_subnet_ids, "[]"))
-}
-
 # Service config
 
 variable "service_name" {
@@ -39,14 +34,6 @@ variable "vpc_id" {
   type = string
 }
 
-variable "private_subnet_ids" {
-  type = string
-}
-
-variable "public_subnet_ids" {
-  type = string
-}
-
 variable "domain_name" {
   type = string
 }