nova-platform/terraform/microservice/main.tf

# Nova sample consumer root — instantiates the L2 microservice pattern.
#
# This is a sample consumer terraform root. It instantiates the L2
# `microservice` module (modules/l2/microservice/terraform), which
# internally composes six L1 primitives (vpc + ecs-cluster + ecs-service +
# iam-role + ecr + alb per D-038) via its own module blocks. The L2 is
# opaque at the stack level (D-012): the consumer root sees ONE module,
# not the individual L1 children.
#
# The platform VPC is referenced via terraform_remote_state (data source)
# so the microservice does not create its own VPC — it reuses the shared
# platform VPC from terraform/platform/main.tf.
#
# State: spike/microservice/<env>/terraform.tfstate (separate from platform/).

terraform {
  required_version = ">= 1.9, < 1.10"
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
  # Partial backend config — the bucket name is supplied at `terraform init`
  # time via `-backend-config=bucket=...` (the bucket is created by
  # terraform/bootstrap/create_state_backend.py as nova-tfstate-<account>-<region>).
  backend "s3" {
    key    = "spike/microservice/dev/terraform.tfstate"
    region = "us-east-1"
  }
}

provider "aws" {
  region = "us-east-1"
}

variable "service_name" {
  description = "Name of the ECS microservice."
  type        = string
  default     = "nova-sample-app"
}

variable "container_image" {
  description = "Container image to deploy (ECR URL)."
  type        = string
}

variable "desired_count" {
  description = "Number of ECS Fargate tasks to run."
  type        = number
  default     = 1
}

variable "container_port" {
  description = "Container port the service listens on."
  type        = number
  default     = 80
}

variable "platform_state_bucket" {
  description = "S3 bucket holding the platform VPC state (nova-tfstate-<account>-<region>)."
  type        = string
}

variable "platform_state_key" {
  description = "S3 key for the platform VPC state (default platform/terraform.tfstate)."
  type        = string
  default     = "platform/terraform.tfstate"
}

variable "platform_state_region" {
  description = "Region of the platform state bucket."
  type        = string
  default     = "us-east-1"
}

# Reference the shared platform VPC via terraform_remote_state. The L2
# microservice module consumes these outputs to wire the ALB + ECS service
# into the platform subnets / security group (no per-contract VPC).
data "terraform_remote_state" "platform" {
  backend = "s3"
  config = {
    bucket = var.platform_state_bucket
    key    = var.platform_state_key
    region = var.platform_state_region
  }
}

# The L2 microservice pattern — opaque at this level (D-012). Internally
# composes vpc + ecs-cluster + ecs-service + iam-role + ecr + alb (D-038).
module "microservice" {
  source = "../modules/l2/microservice/terraform"

  service_name    = var.service_name
  desired_count   = var.desired_count
  container_image = var.container_image
  container_port  = var.container_port

  # The L2 module reads the platform VPC outputs from this data source
  # (subnets, security group) via its own internal wiring — the L2
  # interface is intentionally simplified (D-012/D-013).
  platform_subnet_ids          = split(",", data.terraform_remote_state.platform.outputs.subnet_ids)
  platform_security_group_id   = data.terraform_remote_state.platform.outputs.ecs_security_group_id
}

output "service_arn" {
  description = "The ARN of the deployed ECS service."
  value       = module.microservice.service_arn
}

output "lb_dns_name" {
  description = "The DNS name of the fronting Application Load Balancer."
  value       = module.microservice.lb_dns_name
}