provider "aws" {
  region = local.region
}

locals {
  name   = "ecsdemo-backend"
  region = "us-east-2"

  container_image = "public.ecr.aws/aws-containers/ecsdemo-nodejs:c3e96da"
  container_port  = 3000 # Container port is specific to this app example
  container_name  = "ecsdemo-nodejs"

  tags = {
    Blueprint  = local.name
    GithubRepo = "github.com/aws-ia/ecs-blueprints"
  }
}

################################################################################
# ECS Blueprint
################################################################################

module "ecs_service" {
  source  = "terraform-aws-modules/ecs/aws//modules/service"
  version = "~> 5.0"

  name               = local.name
  desired_count      = 3
  cluster_arn        = data.aws_ecs_cluster.core_infra.arn
  enable_autoscaling = false

  # Task Definition
  requires_compatibilities = ["EC2"]
  capacity_provider_strategy = {
    default = {
      capacity_provider = "core-infra" # needs to match name of capacity provider
      weight            = 1
      base              = 1
    }
  }
  create_iam_role        = false
  task_exec_iam_role_arn = one(data.aws_iam_roles.ecs_core_infra_exec_role.arns)
  enable_execute_command = true

  container_definitions = {
    (local.container_name) = {
      image                    = local.container_image
      readonly_root_filesystem = false
      port_mappings = [
        {
          name          = "${local.container_name}-${local.container_port}"
          protocol      = "tcp",
          containerPort = local.container_port
          hostPort      = local.container_port
        }
      ]
    }
  }

  service_registries = {
    registry_arn = aws_service_discovery_service.this.arn
  }

  subnet_ids = data.aws_subnets.private.ids
  security_group_rules = {
    ingress_all_service = {
      type        = "ingress"
      from_port   = local.container_port
      to_port     = local.container_port
      protocol    = "tcp"
      description = "Service port"
      cidr_blocks = ["0.0.0.0/0"]
    }
  }

  tags = local.tags
}

resource "aws_service_discovery_service" "this" {
  name = local.name

  dns_config {
    namespace_id = data.aws_service_discovery_dns_namespace.this.id

    dns_records {
      ttl  = 10
      type = "A"
    }

    routing_policy = "MULTIVALUE"
  }

  health_check_custom_config {
    failure_threshold = 1
  }
}

################################################################################
# Supporting Resources
################################################################################

data "aws_subnets" "private" {
  filter {
    name   = "tag:Name"
    values = ["core-infra-private-*"]
  }
}

data "aws_ecs_cluster" "core_infra" {
  cluster_name = "core-infra"
}

data "aws_iam_roles" "ecs_core_infra_exec_role" {
  name_regex = "core-infra-execution*"
}

data "aws_service_discovery_dns_namespace" "this" {
  name = "default.${data.aws_ecs_cluster.core_infra.cluster_name}.local"
  type = "DNS_PRIVATE"
}