ECS and Application Load Balancer Ephemeral Ports using Terraform - terraform

Question

I tried to build an ECS cluster with ALB in front using terraform. As I used dynamic port mappping the targets will not be registerd as healthy. I played with the healthcheck and Success codes if I set it to 301 everything is fine.

Answer 1

ECS
data "template_file" "mb_task_template" {
template = file("${path.module}/templates/marketplace-backend.json.tpl")
vars = {
name = "${var.mb_image_name}"
port = "${var.mb_port}"
image = "${aws_ecr_repository.mb.repository_url}"
log_group = "${aws_cloudwatch_log_group.mb.name}"
region = "${var.region}"
}
}
resource "aws_ecs_cluster" "mb" {
name = var.mb_image_name
}
resource "aws_ecs_task_definition" "mb" {
family = var.mb_image_name
container_definitions = data.template_file.mb_task_template.rendered
volume {
name = "mb-home"
host_path = "/ecs/mb-home"
}
}
resource "aws_ecs_service" "mb" {
name = var.mb_repository_url
cluster = aws_ecs_cluster.mb.id
task_definition = aws_ecs_task_definition.mb.arn
desired_count = 2
iam_role = var.aws_iam_role_ecs
depends_on = [aws_autoscaling_group.mb]
load_balancer {
target_group_arn = var.target_group_arn
container_name = var.mb_image_name
container_port = var.mb_port
}
}
resource "aws_autoscaling_group" "mb" {
name = var.mb_image_name
availability_zones = ["${var.availability_zone}"]
min_size = var.min_instance_size
max_size = var.max_instance_size
desired_capacity = var.desired_instance_capacity
health_check_type = "EC2"
health_check_grace_period = 300
launch_configuration = aws_launch_configuration.mb.name
vpc_zone_identifier = flatten([var.vpc_zone_identifier])
lifecycle {
create_before_destroy = true
}
}
data "template_file" "user_data" {
template = file("${path.module}/templates/user_data.tpl")
vars = {
ecs_cluster_name = "${var.mb_image_name}"
}
}
resource "aws_launch_configuration" "mb" {
name_prefix = var.mb_image_name
image_id = var.ami
instance_type = var.instance_type
security_groups = ["${var.aws_security_group}"]
iam_instance_profile = var.aws_iam_instance_profile
key_name = var.key_name
associate_public_ip_address = true
user_data = data.template_file.user_data.rendered
lifecycle {
create_before_destroy = true
}
}
resource "aws_cloudwatch_log_group" "mb" {
name = var.mb_image_name
retention_in_days = 14
}
ALB
locals {
target_groups = ["1", "2"]
}
resource "aws_alb" "mb" {
name = "${var.mb_image_name}-alb"
internal = false
load_balancer_type = "application"
security_groups = ["${aws_security_group.mb_alb.id}"]
subnets = var.subnets
tags = {
Name = var.mb_image_name
}
}
resource "aws_alb_target_group" "mb" {
count = length(local.target_groups)
name = "${var.mb_image_name}-tg-${element(local.target_groups, count.index)}"
port = var.mb_port
protocol = "HTTP"
vpc_id = var.vpc_id
target_type = "instance"
health_check {
path = "/health"
protocol = "HTTP"
timeout = "10"
interval = "15"
healthy_threshold = "3"
unhealthy_threshold = "3"
matcher = "200-299"
}
lifecycle {
create_before_destroy = true
}
tags = {
Name = var.mb_image_name
}
}
resource "aws_alb_listener" "mb_https" {
load_balancer_arn = aws_alb.mb.arn
port = 443
protocol = "HTTPS"
ssl_policy = "ELBSecurityPolicy-2016-08"
certificate_arn = module.dns.certificate_arn
default_action {
type = "forward"
target_group_arn = aws_alb_target_group.mb.0.arn
}
}
resource "aws_alb_listener_rule" "mb_https" {
listener_arn = aws_alb_listener.mb_https.arn
priority = 100
action {
type = "forward"
target_group_arn = aws_alb_target_group.mb.0.arn
}
condition {
field = "path-pattern"
values = ["/health/"]
}
}

Answer 2

Okay. Looks like the code above is working. I had different issue with networking.