✨feat(awsmachinepool): custom lifecyclehooks for machinepools

[sebltm]

What type of PR is this?
/kind feature

What this PR does / why we need it:

This PR adds to the v1beta2 definition for the AWSMachinePool and AWSManagedMachinePool with a new field lifecycleHooks which is a list of:

name: <the name of the lifecycle hook>
notificationTargetARN: <ARN of resource where to send the lifecycle event; optional>
roleARN: <ARN of role to be used when sending notifications; optional>
lifecycleTransition: <autoscaling:EC2_INSTANCE_LAUNCHING/EC2_INSTANCE_TERMINATING>
heartbeatTimeout: <duration of the heartbeat timeout; optional>
defaultResult: <CONTINUE/ABANDON; optional>
notificationMetadata: <some metadata to add to the notification; optional>

The matching webhooks are updated to validate the lifecycle hooks as they are added to the Custom Resource.
The matching reconcilers are updated to enable reconciling those lifecycle hooks: if the lifecycle hook is present in the Custom Resource but not in the cloud, it is created. And if there is a lifecycle hook present in the cloud but not declared in the Custom Resource then it is removed.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #4020

AWS supports Lifecycle Hooks before/after performing certain actions on an ASG. For example, before scaling in (removing) a node, the ASG can publish an event in an SQS queue which can them be consumed by the node-termination-handler to ensure its proper removal from Kubernetes (it will cordon, drain the node and wait for a period of time for applications to be removed before allowing the Autoscaling Group to terminate the instance).

This allows Kubernetes or other components to be aware of the node's lifecycle and take appropriate actions

Special notes for your reviewer:

Checklist:

• squashed commits
• includes documentation
• includes emojis
• adds unit tests
• adds or updates e2e tests

Release note:

Adding support for custom Lifecycle Hooks in AWSMachinePools for external hooks (e.g support for the aws-node-termination-handler with SQS)

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign justinsb for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[k8s-ci-robot]

Welcome @sebltm!

It looks like this is your first PR to kubernetes-sigs/cluster-api-provider-aws 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes-sigs/cluster-api-provider-aws has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[k8s-ci-robot]

Hi @sebltm. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[AndiDog]

I have two requests before getting to the review:

• Neither title nor PR description describe the change. Lifecycle hooks and reacting to node shutdown is great – but what is this PR doing and achieving? Also, the release note entry in the PR template must be filled.
• You're moving lots of code. Please revert those changes as much as possible so the PR becomes reviewable. Refactoring and file renames can be done separately.

[AndiDog]

/assign

[sebltm]

@AndiDog sorry I hadn't cleaned up the PR, I didn't know if it would get some traction :)
I've updated the PR, updated the description. Let me know if it looks good, I'll write some docs and add release notes

[sebltm]

@AndiDog let me know if this looks good or if there's anything else I should take a look at :)

[AndiDog]

The PR is definitely reviewable now. I'm not much experienced with lifecycle hooks and aws-node-termination-handler (is that your actual use case?). Maybe MachinePool machines (#4527) give us a good way to detect node shutdown and have CAPI/CAPA take care of it? Or in other words: I'm not fully confident reviewing here with my knowledge, but maybe others have a better clue – please feel free to ping or discuss in Slack (#cluster-api-aws) so we can find someone to check this feature request.

[AndiDog]

/ok-to-test

[k8s-ci-robot]

@sebltm: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-cluster-api-provider-aws-test	fb7d6af	link	true	/test pull-cluster-api-provider-aws-test

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.