README.md

ecs terraform module

A terraform module to provide ECS clusters in AWS.

This Module currently supports Terraform 0.10.x, but does not require it. If you use tfenv, this module contains a .terraform-version file which matches the version of Terraform we currently use to test with.

Module Input Variables

Required

• name - ECS cluster name
• key_name - An EC2 key pair name
• subnet_id - A list of subnet IDs
• vpc_id - The VPC ID to place the cluster in

Optional

NOTE About User Data: The user_data parameter overwrites the user_data template used by this module, this will break some of the module features (e.g. docker_storage_size, dockerhub_token, and dockerhub_email). However, additional_user_data_script will concatenate additional data to the end of the current user_data script. It is recomended that you use additional_user_data_script. These two parameters are mutually exclusive - you can not pass both into this module and expect it to work.

• additional_user_data_script - Additional user_data scripts content
• ebs_block_device - EBS block devices to attach to the instance. (default: /dev/xvdcz)
• region - AWS Region - defaults to us-east-1
• servers - Number of ECS Servers to start in the cluster - defaults to 1
• min_servers - Minimum number of ECS Servers to start in the cluster - defaults to 1
• max_servers - Maximum number of ECS Servers to start in the cluster - defaults to 10
• instance_type - AWS instance type - defaults to t2.micro
• load_balancers - List of elastic load balancer (classic only) names to put in front of your instances - defaults to []
• iam_path - IAM path, this is useful when creating resources with the same name across multiple regions. Defaults to /
• associate_public_ip_address - assign a publicly-routable IP address to every instance in the cluster - default: false.
• docker_storage_size - EBS Volume size in Gib that the ECS Instance uses for Docker images and metadata - defaults to 22
• dockerhub_email - Email Address used to authenticate to dockerhub. http://docs.aws.amazon.com/AmazonECS/latest/developerguide/private-auth.html
• dockerhub_token - Auth Token used for dockerhub. http://docs.aws.amazon.com/AmazonECS/latest/developerguide/private-auth.html
• extra_tags - Additional tags to be added to the ECS autoscaling group. Must be in the form of an array of hashes. See https://www.terraform.io/docs/providers/aws/r/autoscaling_group.html for examples.

extra_tags = [
    {
      key                 = "consul_server"
      value               = "true"
      propagate_at_launch = true
    },
  ]

• allowed_cidr_blocks - List of subnets to allow into the ECS Security Group. Defaults to ["0.0.0.0/0"].

• ami - A specific AMI image to use, eg ami-95f8d2f3. Defaults to the latest ECS optimized Amazon Linux AMI.

• ami_version - Specific version of the Amazon ECS AMI to use (e.g. 2016.09). Defaults to *. Ignored if ami is specified.

• heartbeat_timeout - Heartbeat Timeout setting for how long it takes for the graceful shutdown hook takes to timeout. This is useful when deploying clustered applications like consul that benifit from having a deploy between autoscaling create/destroy actions. Defaults to 180"

• asg_delete_extra_timeout - Extra time that terraform apply will wait for ASG deletion (default 600). This is added on top of heartbeat_timeout. This variable is customizable for when the instances take longer than 600sec to shut down once shutdown is initiated.

• security_group_ids - a list of security group IDs to apply to the launch configuration

• user_data - The instance user data (e.g. a cloud-init config) to use in the aws_launch_configuration

• custom_iam_policy - JSON containing the custom IAM policy for ECS nodes. Will overwrite the default one if set.

• consul_image - Image to use when deploying consul, defaults to the hashicorp consul image

• registrator_image - Image to use when deploying registrator agent, defaults to the gliderlabs registrator:latest

• consul_memory_reservation - The soft limit (in MiB) of memory to reserve for the container, defaults 20

• registrator_memory_reservation - The soft limit (in MiB) of memory to reserve for the container, defaults 20

• enable_agents - Enable Consul Agent and Registrator tasks on each ECS Instance. Defaults to false

• spot_bid_price - Use spot instances and request this bid price. Note that with this option you risk your instances shutting down if the market price rises above your bid price.

• enabled_metrics - A list of metrics to collect.

Usage

module "ecs-cluster" {
  source    = "github.com/terraform-community-modules/tf_aws_ecs"
  name      = "infra-services"
  servers   = 1
  subnet_id = ["subnet-6e101446"]
  vpc_id    = "vpc-99e73dfc"
}

Example cluster with consul and Registrator

In order to start the Consul/Registrator task in ECS, you'll need to pass in a consul config into the additional_user_data_script script parameter. For example, you might pass something like this:

Please note, this module will try to mount /etc/consul/ into /consul/config in the container and assumes that the consul config lives under /etc/consul on the docker host.

/bin/mkdir -p /etc/consul
cat <<"CONSUL" > /etc/consul/config.json
{
	"raft_protocol": 3,
	"log_level": "INFO",
	"enable_script_checks": true,
  "datacenter": "${datacenter}",
	"retry_join_ec2": {
		"tag_key": "consul_server",
		"tag_value": "true"
	}
}
CONSUL

data "template_file" "ecs_consul_agent_json" {
  template = "${file("ecs_consul_agent.json.sh")}"

  vars {
    datacenter = "infra-services"
  }
}

module "ecs-cluster" {
  source                      = "github.com/terraform-community-modules/tf_aws_ecs"
  name                        = "infra-services"
  servers                     = 1
  subnet_id                   = ["subnet-6e101446"]
  vpc_id                      = "vpc-99e73dfc"
  additional_user_data_script = "${data.template_file.ecs_consul_agent_json.rendered}"
  enable_agents               = true
}

Outputs

• cluster_id - (String) ECS Cluster id for use in ECS task and service definitions.
• cluster_name - (String) ECS Cluster name that can be used for CloudWatch app autoscaling policy resource_id.
• autoscaling_group (Map) A map with keys id, name, and arn of the aws_autoscaling_group created.
• iam_role (Map) A map with keys arn and name of the iam_role created.
• security_group (Map) A map with keys id, name, and arn of the aws_security_group created.

Authors

• Tim Hartmann
• Joe Stump
• Michal

License

MIT