spot-drainer (deprecated)

As per Sep 27, 2019 Amazon supports automated draining for spot instances running ECS services (announcement).

Codebase will be left for educational purpose.

Amazon EC2 Spot Instances offer spare compute capacity available in the AWS cloud at steep discounts compared to On-Demand instances. Spot Instances can be interrupted by EC2 with two minutes of notification when EC2 needs the capacity back. The two-minute warning for Spot instances is available via Amazon CloudWatch Events

This Lambda function reacts to such CloudWatch event annd set a spot ec2 instance to DRAINING state if the instance is used in an ECS cluster.

CloudWatch event

{
  "version": "0",
  "id": "12345678-1234-1234-1234-123456789012",
  "detail-type": "EC2 Spot Instance Interruption Warning",
  "source": "aws.ec2",
  "account": "123456789012",
  "time": "2018-07-18T09:40:00Z",
  "region": "eu-west-1",
  "resources": [
    "arn:aws:ec2:eu-west-1:123456789012:instance/i-1234567890abcdef0"
  ],
  "detail": {
    "instance-id": "i-055eef5d6b5fcdfc8",
    "instance-action": "action"
  }
}

Deployment requirements

• docker
• make
• aws cli

Deployment

Use the included Makefile to deploy the resources.

The OWNER env var is for tagging. So you can set this to what you want. The ENVIRONMENT env var is also for naming + tagging, but will also be included in CloudWatch logs. This so you can make out differences between dev, test and prod etc. if you're running them on the same AWS Account.

AWS_PROFILE=my-profile AWS_REGION=region OWNER=TeamName S3_BUCKET=my-artifact-bucket ECS_CLUSTER=target-ecs-cluster make deploy

Example

AWS_PROFILE=default AWS_REGION=eu-west-1 OWNER=cloudops S3_BUCKET=my-artifact-bucket ECS_CLUSTER=cluster-one-prod make deploy