AWS ECS Service

This module creates an ECS Service in an existing ECS Cluster.

Load Balancing

This module supports the use of ALBs and NLBs by accepting the ARN of a Load Balancer Listener and creating the target group for the service. In order to use Load Balancing, set the load_balancer_target_groups variable with the list of Target Group ARNs that the ECS Service should register with.

Service Discovery

Service Discovery is supported by creating a Service Discovery Service via this module and allowing the configuration of the DNS settings for the service. In order to use Service Discovery, the enable_service_discovery input variable must be set to true and the ID of an existing Service Discovery Namespace must be passed in. There are several service discovery input variables that be adjusted to change the behavior Service Discovery.

Auto Scaling

This module supports Auto Scaling via a Target Tracking Policy that can be either set against CPU or Memory utilization. In order to use Auto Scaling, the enable_auto_scaling input variable must be set to true. There are multiple auto scaling input variables that be set to adjust the task scaling.

Note: In order to tag ECS Service resources, you must have opted in to the new ARN and Resource ID settings for ECS - if not the ECS Service will fail to create. If you have not opted in, you can set the ecs_service_tagging_enabled input variable to false - which will not tag the ECS Service.

Usage

data aws_vpc _ {
  id = "vpc-abc123"
}

data aws_subnet_ids private {
  vpc_id = data.aws_vpc._.id

  filter {
    name   = "tag:Tier"
    values = ["Private"]
  }
}

resource aws_cloudwatch_log_group log_group {
  name = "my-example-log-group"

  tags = local.tags
}

resource aws_ecs_cluster cluster {
    name = "my-example-cluster"
    
    capacity_providers = ["FARGATE"]
}

module container {
  source = "terraform-aws-container-defintion"
  
  image = "nginx"
}

module service {
  source = "terraform-aws-ecs-service"

  vpc_id = data.aws_vpc._.id

  name         = "my-example-service"
  cluster_name = data.aws_ecs_cluster._.cluster_name

  task_definition = jsonencode([module.container.definition])
  task_cpu        = 1024
  task_memory     = 2048

  networking_subnets          = data.aws_subnet_ids.private.ids

  enable_service_discovery              = true
  service_discovery_namespace_id        = aws_service_discovery_private_dns_namespace.namespace.id
  service_discovery_ingress_cidr_blocks = [data.aws_vpc._.cidr_block]

  ingress_protocol         = "TCP"
  ingress_target_container = "nginx"
  ingress_target_port      = 80

  cloudwatch_log_group_arn = aws_cloudwatch_log_group.log_group.arn

  ecs_service_tagging_enabled = false
}