ECS Cluster Terraform Module

Terraform module which creates Amazon ECS cluster with EC2 launch type

This module creates following resources:

1. ECS cluster
2. Capacity providers
3. Autoscaling groups for EC2
4. Launch configuration for EC2

Usage

module "app_cluster" {
  source       = "git::https://github.com/gaussb-labs/terraform-aws-ecs-cluster-module.git?ref=v1.1.2"
  environment  = "production"
  cluster_name = "app_cluster"
  launch_configs = [
    {
      name                      = "java_application"
      image_id                  = "ami-040d909ea4e56f8f3"
      instance_type             = "t3a.medium"
      user_data_base64          = ""
      iam_instance_profile_name = "ecs_agent_access_instance_profile"
      root_block_device = {
        volume_type = "gp3"
        volume_size = 30
      }
      security_group_ids = ["sg-01", "sg-02"]
    },
    {
      name                      = "rails_application"
      image_id                  = "ami-040d909ea4e56f8f3"
      instance_type             = "t3a.medium"
      user_data_base64          = ""
      iam_instance_profile_name = "ecs_agent_access_instance_profile"
      security_group_ids = ["sg-03", "sg-04"]
    }
  ]
  asg = [
    {
      name                      = "java_application"
      vpc_zone_identifier       = ["subnet_id_1", "subnet_id_2"]
      health_check_type         = "EC2"
      health_check_grace_period = 10
      max_size                  = 3
      min_size                  = 1
      protect_from_scale_in     = true
      additional_tags           = []
    },
    {
      name                      = "rails_application"
      vpc_zone_identifier       = ["subnet_id_1", "subnet_id_2"]
      health_check_type         = "EC2"
      health_check_grace_period = 10
      max_size                  = 2
      min_size                  = 0
      protect_from_scale_in     = false
      additional_tags           = []
    }
  ]
  capacity_providers = [
    {
      name                           = "java_application"
      target_capacity                = 100
      managed_scaling_status         = "ENABLED"
      managed_termination_protection = "ENABLED"
    },
    {
      name                           = "rails_application"
      target_capacity                = 100
      managed_scaling_status         = "ENABLED"
      managed_termination_protection = "DISABLED"
    }
  ]
}

NOTE:
This module doesn't provide the ability to create ECS services and tasks. This can be created separately and should be closer to the application deployments rather than the infrastructure deployments.

Configuration

1. asg

asg is a list of auto-scaling group configuration. This module supports multiple asg configurations per cluster. This is useful in scenarios where we need different auto-scaling for different kind of workloads. launch_config is required for auto-scaling group.

2. launch_configs

launch_configs is a list of launch configurations, used by the auto-scaling groups to spin up new EC2 instances. One launch configuration per auto-scaling group is supported, although we can specify multiple launch configurations if there are multiple auto-scaling groups defined. The launch configuration is linked to the auto-scaling group via the name attribute, so name has to same for both asg and launch configuration.

iam_instance_profile_name is expected by this module. The instance_profile should be created considering the accesses needed by the ECS agent to interact with the ECS cluster and service.

3. capacity_providers

Configuration block for defining capacity providers in the ECS cluster. This is needed if you plan to use capacity provider strategy for ECS service. asg and launch_config are required for the capacity provider.

Requirements

Name	Version
terraform	>= 1.2.0
aws	~> 4.16
cloudinit	>=2.2.0

Providers

Name	Version
aws	~> 4.16

Modules

No modules.

Resources

Name	Type
aws_autoscaling_group.ecs_cluster_asg	resource
aws_ecs_capacity_provider.capacity_providers	resource
aws_ecs_cluster.ecs_cluster	resource
aws_ecs_cluster_capacity_providers.ecs_cluster_capacity_provider	resource
aws_launch_configuration.ecs_launch_config	resource

Inputs

Name	Description	Type	Default	Required
environment	The cluster deployment environment. environment is added as prefix to the resources generated by this module.	string	n/a	yes
cluster_name	Name of ECS cluster. environment is not added to the cluster name.	string	n/a	yes
capacity_providers	List of capacity provider configuration.	list(object)	n/a	yes
capacity_providers.name	Capacity provider name. This is used by the module to link auto-scaling group, launch configuration and capacity provider.	string	n/a	yes
capacity_providers.target_capacity	Target utilisation for the capacity provider. A value between 1 and 100.	number	n/a	yes
capacity_providers.managed_scaling_status	Whether auto-scaling is managed by ECS. Valid values are ENABLED and DISABLED.	string	n/a	yes
capacity_providers.managed_termination_protection	Manage container-aware termination of instances in the auto scaling group when scale-in happens. Valid values are ENABLED and DISABLED.	string	n/a	yes
asg	List of auto-scaling group configuration.	list(object)	n/a	yes
asg.name	Name of auto-scaling group.	string	n/a	yes
asg.vpc_zone_identifier	List of subnet Ids to launch resources in.	list(string)	n/a	yes
asg.health_check_type	Controls how health check is done. Valid values are EC2 and ELB.	string	n/a	yes
asg.health_check_grace_period	Time in seconds after instance comes up and health check first kicks in.	number	n/a	yes
asg.max_size	The maximum capacity auto-scaling group can scale-out to.	number	n/a	yes
asg.min_size	The minimum capacity auto-scaling group can scale-in to.	number	n/a	yes
asg.protect_from_scale_in	Indicates whether newly launched instances are automatically protected from termination by auto-scaling group when scaling in.	bool	n/a	yes
asg.additional_tags	List of additional tags.	list(object)	n/a	yes
asg.additional_tags.key	Key of the tag.	string	n/a	yes
asg.additional_tags.value	Value of the tag.	string	n/a	yes
asg.additional_tags.propagate_at_launch	Indicates whether to propagate the tag to the newly launched EC2 instances.	bool	n/a	yes
launch_configs	List of launch configurations for auto-scaling groups.	list(object)	n/a	yes
launch_configs.name	Name of the launch configuration. Should be same as corresponding auto-scaling group name.	string	n/a	yes
launch_configs.image_id	AMI Id of the image to use.	string	n/a	yes
launch_configs.instance_type	The type of EC2 instance to use. Eg: t3.small	string	n/a	yes
launch_configs.user_data_base64	Base64 encoded userdata.	string	n/a	yes
launch_configs.iam_instance_profile_name	Name of the IAM instance profile to attach to the EC2 instance.	string	n/a	yes
launch_configs.security_group_ids	List of security group ids to attach to the EC2 instance.	list(string)	n/a	yes
launch_configs.root_block_device	root block device configuration

Outputs

No outputs.

License

MIT Licensed. See LICENSE for full details.