Terraform error - ECS using spot instances to host containers - amazon-web-services

Question

Sorry for long post but hope that will provide good background.
Do not know if that is a bug or my code is wrong. I want to create ECS cluster with EC2 spot instances with help of launch template and ASG. My code is as follows:
For ECS service, cluster, task definition:
resource "aws_ecs_cluster" "main" {
name = "test-ecs-cluster"
}
resource "aws_ecs_service" "ec2_service" {
for_each = data.aws_subnet_ids.all_subnets.ids
name = "myservice_${replace(timestamp(), ":", "-")}"
task_definition = aws_ecs_task_definition.task_definition.arn
cluster = aws_ecs_cluster.main.id
desired_count = 1
launch_type = "EC2"
health_check_grace_period_seconds = 10
load_balancer {
container_name = "test-container"
container_port = 80
target_group_arn = aws_lb_target_group.alb_ec2_ecs_tg.id
}
network_configuration {
security_groups = [aws_security_group.ecs_ec2.id]
subnets = [each.value]
assign_public_ip = "false"
}
ordered_placement_strategy {
type = "binpack"
field = "cpu"
}
}
resource "aws_ecs_task_definition" "task_definition" {
container_definitions = data.template_file.task_definition_template.rendered
family = "test-ec2-task-family"
execution_role_arn = aws_iam_role.ecs_task_exec_role_ec2_ecs.arn
task_role_arn = aws_iam_role.ecs_task_exec_role_ec2_ecs.arn
network_mode = "awsvpc"
memory = 1024
cpu = 1024
requires_compatibilities = ["EC2"]
lifecycle {
create_before_destroy = true
}
}
data "template_file" "task_definition_template" {
template = file("${path.module}/templates/task_definition.json.tpl")
vars = {
container_port = var.container_port
region = var.region
log_group = var.cloudwatch_log_group
}
}
Launch template:
resource "aws_launch_template" "template_for_spot" {
name = "test-spor-ecs-launch-template"
disable_api_termination = false
instance_type = "t3.small"
image_id = data.aws_ami.amazon_linux_2_ecs_optimized.id
key_name = "FrankfurtRegion"
user_data = data.template_file.user_data.rendered
vpc_security_group_ids = [aws_security_group.ecs_ec2.id]
monitoring {
enabled = var.enable_spot == "true" ? false : true
}
block_device_mappings {
device_name = "/dev/sda1"
ebs {
volume_size = 30
}
}
iam_instance_profile {
arn = aws_iam_instance_profile.ecs_instance_profile.arn
}
lifecycle {
create_before_destroy = true
}
}
data "template_file" "user_data" {
template = file("${path.module}/user_data.tpl")
vars = {
cluster_name = aws_ecs_cluster.main.name
}
}
ASG with scaling policy:
resource "aws_autoscaling_group" "ecs_spot_asg" {
name = "test-asg-for-ecs"
max_size = 4
min_size = 2
desired_capacity = 2
termination_policies = [
"OldestInstance"]
vpc_zone_identifier = data.aws_subnet_ids.all_subnets.ids
health_check_type = "ELB"
health_check_grace_period = 300
mixed_instances_policy {
instances_distribution {
on_demand_percentage_above_base_capacity = 0
spot_instance_pools = 2
spot_max_price = "0.03"
}
launch_template {
launch_template_specification {
launch_template_id = aws_launch_template.template_for_spot.id
version = "$Latest"
}
override {
instance_type = "t3.large"
}
override {
instance_type = "t3.medium"
}
override {
instance_type = "t3a.large"
}
override {
instance_type = "t3a.medium"
}
}
}
lifecycle {
create_before_destroy = true
}
}
resource "aws_autoscaling_policy" "ecs_cluster_scale_policy" {
autoscaling_group_name = aws_autoscaling_group.ecs_spot_asg.name
name = "test-ecs-cluster-scaling-policy"
policy_type = "TargetTrackingScaling"
adjustment_type = "ChangeInCapacity"
target_tracking_configuration {
target_value = 70
customized_metric_specification {
metric_name = "ECS-cluster-metric"
namespace = "AWS/ECS"
statistic = "Average"
metric_dimension {
name = aws_ecs_cluster.main.name
value = aws_ecs_cluster.main.name
}
}
}
}
EDIT:
I'm getting :
Error: InvalidParameterException: Creation of service was not idempotent. "test-ec2-service-qaz"
on ecs.tf line 5, in resource "aws_ecs_service" "ec2_service":
5: resource "aws_ecs_service" "ec2_service" {
EDIT2:
Changed ecs_service name to name = "myservice_${replace(timestamp(), ":", "-")}", still getting same error.
Was reading from other issues that it is becouse of usage lifecycle with create_before_destroy statement in ecs_service, but it is not declared in my code. Maybe it is something related to something else, can't say what.

Answer 1

Thanks #Marko E and #karnauskas on github with name = "myservice_${each.value}" was able to deploy three ECS services. With correction to sub-nets handling I was able to deploy all the "stuff" as required. Subnets:
data "aws_subnet_ids" "all_subnets" {
vpc_id = data.aws_vpc.default.id
}
data "aws_subnet" "subnets" {
for_each = data.aws_subnet_ids.all_subnets.ids
id = each.value
}