Bootstraps an ECS Cluster
Requires the boto3 python package and python3. AWS permissions are needed in order to run the deployment
Configuration options are stored in the file config.yml
Just type make!
Creates an ECS Cluster and cluster Security Group for use in ECS Service load balancers.
Configures an autoscaling group that will attach to the ECS Cluster on startup. The instance type, ami ID and initial group size are configurable.
The ASG will automatically expand/contract to fit the needs of the cluster until it reaches its upper/lower bound. The scaling is based upon a custom Cloudwatch metric that is posted by the metric lambda
When scaling in, the instances to be terminated have their tasks stopped gracefully by the lifecycle lambda
Runs on a 1 minute cron and posts a metric AdditionalTasks to cloudwatch that is used for scaling the auto scaling group
AdditionalTasks is the number of additional tasks that can be scheduled on the cluster. It is calculated by finding the most resource intensive task and determining how many more times it can fit on the cluster.
Upon instance shutdown sets the instance to DRAINING. Checks back until either the configurable TaskStopTimeout has been reached or all tasks have stopped, and then terminates the instance.