ASG and lifecycle hooks ASG and lifecycle hooks Sibi Prabakaran May 15, 2019

Objective Objective Run scripts before terminating EC2 instances of an ASG group Like de registering the instances from ALB. Inform Kubernetes/Nomad that this instance is in-eligible for new tasks

Terminology Terminology ASG: Collection of EC2 instances with policies on scaling. Lifecycle hooks: Like callbacks which can be added to ASG.

ASG Events ASG Events Scale Out: Instructs ASG to launch new instances. Scale In: Instructs ASG to detach EC2 instances. Fired on Manually increasing the size of the group Based on Policy (like demand) Based on Schedule

ASG Events (2) ASG Events (2) On receiving the events, the ASG will put the instance into Pending or Terminating state. If you have defined any lifecycle hooks - that will happen in this state. Timeouts

lifecycled lifecycled Daemon built by buildkite for gracefully handling EC2 scaling events. When a termination notice is received, lifecycled runs a user provided script before proceeding to shutdown the instance. Repo: https://github.com/buildkite/lifecycled

Demo Demo PR: https://github.com/fpco/terraform-aws-foundation/pull/189 Testing instance: http://18.222.32.132:3000 Based on vpc scenario 1 (VPC with single public subnet). ASG with two EC2 instances, also registered with ELB. Instances has lifecycled installed on it.

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