fix #7

README.md

@@ -40,15 +40,6 @@ Any subnet.subnet_group must refer to an existing key in the subnet_groups map.
 Use networkaddress_bits to define the amount of addresses provisioned for the
 subnet. This number must be higher than 3.
 
-## Troubleshooting
-
-### Error when creating cheap nat instances.
-
-There is a dependency problem when createing cheap nat instances. 
-
-**Solution** First enable NAT in network.json, `terraform apply`, then set
-`use_nat_instances = true` and rerun `terraform apply`.
-
 ## Future work / ideas
 
 Possibility of automatically adding subnet groups when new availability zones

nat.tf

@@ -1,5 +1,5 @@
 resource "aws_eip" "this" {
-  for_each = { for key in local.availability_zones_with_nat : key => key }
+  for_each = { for key in local.availability_zones_with_nat : key => key if !var.use_nat_instances }
 
   #vpc = true # dont support EC2-ClassicLink but otherwise TF keeps reacreating this resource
   domain = "vpc"
@@ -32,17 +32,20 @@ resource "aws_nat_gateway" "this" {
 module "nat_instances" {
   source = "./nat_instances"
 
-  for_each = { for k, v in aws_eip.this : k => v if var.use_nat_instances }
+  for_each = { for key in local.availability_zones_with_nat : key => key if var.use_nat_instances}
 
   name        = "${var.name}-${each.key}"
   kms_key_arn = var.kms_key_arn
   # fetch first public subnet to locate nat gateway in in the same az zone, if not available then crash
   public_subnet_id           = element([for key, value in aws_subnet.this : value if value.availability_zone == each.key && !var.configuration.subnet_groups[var.configuration.subnets[key].subnet_group].nat_gateway && var.configuration.subnet_groups[var.configuration.subnets[key].subnet_group].internet_gateway], 0).id
-  elastic_ip_id              = each.value.id
   sqs_dlq_arn                = var.sqs_dlq_arn
   route_nat_gateway_tag_name = local.route_nat_gateway_tag_name
 
   nat_route_table_arns = [for k, v in aws_route_table.this : v.arn if v.tags[local.route_nat_gateway_tag_name] == "true"]
+
+  depends_on = [
+    aws_internet_gateway.this
+  ]
 }
 
 resource "aws_route" "nat_gateway" {

nat_instances/main.tf

@@ -5,7 +5,6 @@ module "ec2_asg" {
   initial_amount_of_pods = 1
 
   name                   = var.name
-  #initial_amount_of_pods = 1
 
   ec2_ami_name_filter_list = ["amzn2-ami-ecs-hvm-2.0.*-arm64-ebs"]
   ec2_ami_owner_list       = ["591542846629"] # Amazon
@@ -21,7 +20,6 @@ module "ec2_asg" {
   subnet_ids                = [var.public_subnet_id]
   use_public_ip             = false # we are the NAT gateway
   use_floating_ip           = true
-  own_eip_for_floaing_ip    = var.elastic_ip_id
   user_data_completion_hook = true
   sqs_dlq_arn               = var.sqs_dlq_arn
   kms_key_arn               = var.kms_key_arn

nat_instances/variables.tf

@@ -13,11 +13,6 @@ variable "public_subnet_id" {
   type        = string
 }
 
-variable "elastic_ip_id" {
-  description = "Elastic IP"
-  type        = string
-}
-
 variable "sqs_dlq_arn" {
   description = "SQS DLQ Arn to transfer unprocessed / failed infra messages into."
   type        = string