Single task ECS service provisioning with Terraform

This is yet another module to run containerized applications on AWS ECS using Terraform for infrastructure provisioning. This module is built for deploying ECS services running tasks with a single container definition within a VPC. Optionally service discovery namespace and autoscaling groups can also be specified as input.

This module simplifies several steps in the creation of an ECS service with a single container task definition and it is therefore not suitable if one needs fine-grained tuning of the container definition and security properties.

Usage

The module can be used for creating a simple service as follows:

provider "aws" { }

resource "aws_ecs_cluster" "ecs_cluster" {
  name = var.cluster_name
}

module "sample_app" {

  source = "github.com/madagra/terraform-aws-single-task-service"

  task_name       = "sample_app"
  vpc_id          = module.vpc.vpc_id
  vpc_subnets     = module.vpc.private_subnets
  task_exec_role  = aws_iam_role.ecs_execution.arn

  has_discovery = true
  dns_namespace = aws_service_discovery_private_dns_namespace.sample_namespace.id

  open_ports      = [80, 8080]
  ecs_cluster     = "ecs_cluster"
  container_image = "python:3.8-slim"

  environment = [
    {
      "name" : "EXAMPLE_ENV"
      "value" : "sample"
    }
  ]
}

More complete examples can be found in the examples/ folder which contains:

• examples/basic: A basic example of an ECS service with minimal features provisioned with the module.
• example/python: A sample Python application which can be used for testing the module with multiple communicating services.

Requirements

Name	Version
terraform	>= 0.13.5
aws	>= 3.0.0

Providers

Name	Version
aws	>= 3.0.0

Inputs

Name	Description	Type	Default	Required
alb_port	If load balanced service this is the application port for the target group	number	0	no
alb_target_group	If the service is associated with an application load balancer this is the ALB target group	string	null	no
capacity_provider	The capacity provider name for the autoscaling group	string	null	no
container_image	The Docker image to run with the task	string	n/a	yes
deployment_maximum_percent	The maximum number of tasks which can run during redeployment of the service	number	100	no
deployment_minimum_healthy_percent	The minimum percentage of running tasks to consider the service healthy	number	50	no
desired_count	The desired number of the ECS task to run	number	1	no
dns_namespace	The Route53 DNS namespace where the ECS task is registered	string	null	no
ecs_cluster	The ECS cluster ID where the service should run	string	n/a	yes
environment	The container environmental variables	list(map(string))	[]	no
has_alb	Whether the service should be registered to an application load balancer	bool	false	no
has_asg	Whether the service is associated with an autoscaling group of EC2 instances	bool	false	no
has_discovery	Flag to switch on service discovery. If true, a valid DNS namespace must be provided	bool	false	no
has_logs	Whether to forward logging to CloudWatch	bool	false	no
logs_region	The region where the CloudWatch logs group is created	string	null	no
open_ports	The ports which should be opened in the container and the security group to allow communication among services	list(string)	[]	no
security_groups	Additional security groups to assign to the ECS service	list(string)	[]	no
task_cpu	The CPU percentage allocated for the ECS task in vCPU units	number	512	no
task_exec_role	The IAM role which is assumed by the ECS tasks	string	n/a	yes
task_launch_type	The launch type for the ECS task. Choose between EC2 and FARGATE	string	"EC2"	no
task_memory	The memory allocated for the ECS task in Mb	number	512	no
task_name	The task name which gives the name to the ECS task, container and service discovery name	string	n/a	yes
task_network_mode	The network mode for the ECS task	string	"awsvpc"	no
vpc_cidr	The trusted VPC CIDR to assign to the task security group ingress block	list(string)	[ "0.0.0.0/0" ]	no
vpc_id	The ID of the VPC where the ECS cluster is running	string	n/a	yes
vpc_subnets	The VPC subnets where the application should run	list(string)	n/a	yes

Outputs

Name	Description
service_arn	The ARN of the ECS service created
task_family	The family of your task definition, used as the definition name
task_revision	The revision of the task in a particular family