Support LifecycleHookSpecificationList for the L2 AutoScalingGroup construct

[RikJansen81]

AutoScalingGroup#addLifecycleHook inserts a LifeCycleHook-resrouce in the CFN-template that depends on the referenced ASG. This will result in the hook being created after the initial ASG (and its instances) have been created. Therefore, the hooks are not triggered for these initial instances.

CFN allows the use of LifecycleHookSpecificationList in the ASG specification. These hooks will also fire for the instances in the initial group.

Use Case

I would like my hooks to be triggered for all instances in my ASG, not only after a scaling event.

Proposed Solution

Extend interface AutoScalingGroupProps with property lifecycleHookSpecificationList and render according specifications.

There are two "reasonable" workarounds:

1. Use the Cfn-classes
2. Deploy first with desiredCapacity = 0, and then again with the desired desiredCapacity.

• 👋 I may be able to implement this feature request
• ⚠️ This feature might incur a breaking change

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This is a 🚀 Feature Request

[ddneilson]

+1 -- From personal experience, just now, it's a nasty surprise to set up a lifecyclehook using the existing L2 mechanisms to only discover that the instance-launch event isn't being received for all instances in the ASG. You, obviously, don't get it for instances that came up before CloudFormation completed setting up the LifecycleHook resource.

Back-dooring the L1 works, but it feels bad.

[joaocpinto]

I was also hit by this, which creates an edge case for the first launched instance and makes it harder to handle circular dependencies unless we use deterministic ASG or Lifecycle hook names - eg. if the user data need the hook name that is not yet created, then we cannot use the lifecycleHookName property.

[dmortim]

Any movement on this one? Would be great if lifecycle hooks could be created on the ASG object prior to ASG instances being launched.

[jesterhazy]

any update on this? not having this makes the L2 constructs pretty useless unless you are OK with zero initial capacity