Fix: Error when creating subnets more than AZ (#8516)

contrib/terraform/aws/create-infrastructure.tf

@@ -20,7 +20,7 @@ module "aws-vpc" {
 
   aws_cluster_name         = var.aws_cluster_name
   aws_vpc_cidr_block       = var.aws_vpc_cidr_block
-  aws_avail_zones          = slice(data.aws_availability_zones.available.names, 0, length(var.aws_cidr_subnets_public) <= length(data.aws_availability_zones.available.names) ? length(var.aws_cidr_subnets_public) : length(data.aws_availability_zones.available.names))
+  aws_avail_zones          = data.aws_availability_zones.available.names
   aws_cidr_subnets_private = var.aws_cidr_subnets_private
   aws_cidr_subnets_public  = var.aws_cidr_subnets_public
   default_tags             = var.default_tags
@@ -31,7 +31,7 @@ module "aws-elb" {
 
   aws_cluster_name      = var.aws_cluster_name
   aws_vpc_id            = module.aws-vpc.aws_vpc_id
-  aws_avail_zones       = slice(data.aws_availability_zones.available.names, 0, length(var.aws_cidr_subnets_public) <= length(data.aws_availability_zones.available.names) ? length(var.aws_cidr_subnets_public) : length(data.aws_availability_zones.available.names))
+  aws_avail_zones       = data.aws_availability_zones.available.names
   aws_subnet_ids_public = module.aws-vpc.aws_subnet_ids_public
   aws_elb_api_port      = var.aws_elb_api_port
   k8s_secure_api_port   = var.k8s_secure_api_port
@@ -54,7 +54,6 @@ resource "aws_instance" "bastion-server" {
   instance_type               = var.aws_bastion_size
   count                       = var.aws_bastion_num
   associate_public_ip_address = true
-  availability_zone           = element(slice(data.aws_availability_zones.available.names, 0, length(var.aws_cidr_subnets_public) <= length(data.aws_availability_zones.available.names) ? length(var.aws_cidr_subnets_public) : length(data.aws_availability_zones.available.names)), count.index)
   subnet_id                   = element(module.aws-vpc.aws_subnet_ids_public, count.index)
 
   vpc_security_group_ids = module.aws-vpc.aws_security_group
@@ -79,8 +78,7 @@ resource "aws_instance" "k8s-master" {
 
   count = var.aws_kube_master_num
 
-  availability_zone = element(slice(data.aws_availability_zones.available.names, 0, length(var.aws_cidr_subnets_public) <= length(data.aws_availability_zones.available.names) ? length(var.aws_cidr_subnets_public) : length(data.aws_availability_zones.available.names)), count.index)
-  subnet_id         = element(module.aws-vpc.aws_subnet_ids_private, count.index)
+  subnet_id = element(module.aws-vpc.aws_subnet_ids_private, count.index)
 
   vpc_security_group_ids = module.aws-vpc.aws_security_group
 
@@ -110,8 +108,7 @@ resource "aws_instance" "k8s-etcd" {
 
   count = var.aws_etcd_num
 
-  availability_zone = element(slice(data.aws_availability_zones.available.names, 0, length(var.aws_cidr_subnets_public) <= length(data.aws_availability_zones.available.names) ? length(var.aws_cidr_subnets_public) : length(data.aws_availability_zones.available.names)), count.index)
-  subnet_id         = element(module.aws-vpc.aws_subnet_ids_private, count.index)
+  subnet_id = element(module.aws-vpc.aws_subnet_ids_private, count.index)
 
   vpc_security_group_ids = module.aws-vpc.aws_security_group
 
@@ -134,8 +131,7 @@ resource "aws_instance" "k8s-worker" {
 
   count = var.aws_kube_worker_num
 
-  availability_zone = element(slice(data.aws_availability_zones.available.names, 0, length(var.aws_cidr_subnets_public) <= length(data.aws_availability_zones.available.names) ? length(var.aws_cidr_subnets_public) : length(data.aws_availability_zones.available.names)), count.index)
-  subnet_id         = element(module.aws-vpc.aws_subnet_ids_private, count.index)
+  subnet_id = element(module.aws-vpc.aws_subnet_ids_private, count.index)
 
   vpc_security_group_ids = module.aws-vpc.aws_security_group
 

contrib/terraform/aws/modules/elb/main.tf

@@ -28,7 +28,7 @@ resource "aws_security_group_rule" "aws-allow-api-egress" {
 # Create a new AWS ELB for K8S API
 resource "aws_elb" "aws-elb-api" {
   name            = "kubernetes-elb-${var.aws_cluster_name}"
-  subnets         = var.aws_subnet_ids_public
+  subnets         = length(var.aws_subnet_ids_public) <= length(var.aws_avail_zones) ? var.aws_subnet_ids_public : slice(var.aws_subnet_ids_public, 0, length(var.aws_avail_zones))
   security_groups = [aws_security_group.aws-elb.id]
 
   listener {

contrib/terraform/aws/modules/vpc/main.tf

@@ -25,8 +25,8 @@ resource "aws_internet_gateway" "cluster-vpc-internetgw" {
 
 resource "aws_subnet" "cluster-vpc-subnets-public" {
   vpc_id            = aws_vpc.cluster-vpc.id
-  count             = length(var.aws_avail_zones)
-  availability_zone = element(var.aws_avail_zones, count.index)
+  count             = length(var.aws_cidr_subnets_public)
+  availability_zone = element(var.aws_avail_zones, count.index % length(var.aws_avail_zones))
   cidr_block        = element(var.aws_cidr_subnets_public, count.index)
 
   tags = merge(var.default_tags, tomap({
@@ -43,8 +43,8 @@ resource "aws_nat_gateway" "cluster-nat-gateway" {
 
 resource "aws_subnet" "cluster-vpc-subnets-private" {
   vpc_id            = aws_vpc.cluster-vpc.id
-  count             = length(var.aws_avail_zones)
-  availability_zone = element(var.aws_avail_zones, count.index)
+  count             = length(var.aws_cidr_subnets_private)
+  availability_zone = element(var.aws_avail_zones, count.index % length(var.aws_avail_zones))
   cidr_block        = element(var.aws_cidr_subnets_private, count.index)
 
   tags = merge(var.default_tags, tomap({