Disabling ASG process AZRebalance by default

[max-rocket-internet]

PR o'clock

Description

Disabling ASG process AZRebalance by default.

I can't think of a single reason why this wouldn't be a good idea to have disabled by default? If the ASG makes any changes to your instances, they need to be drained first and not terminated at will by the ASG.

Checklist

• terraform fmt and terraform validate both work from the root and examples/eks_test_fixture directories (look in CI for an example)
• Tests for the changes have been added and passing (for bug fixes/features)
• Test results are pasted in this PR (in lieu of CI)
• I've added my change to CHANGELOG.md
• Any breaking changes are highlighted above

[max-rocket-internet]

Some extra info:
kubernetes/autoscaler#1802
kubernetes/kops#3319

[rchernobelskiy]

One reason I can think of to leave it enabled would be to prevent pods being unschedulable due to their ebs volumes being in a zone without a node.
Or is there a better way to prevent that?
Seems like the recommended solution of asg per zone would be pretty convoluted terraform.

[max-rocket-internet]

to prevent pods being unschedulable due to their ebs volumes being in a zone without a node.

This doesn't change the problem though: the ASG doesn't drain nodes gracefully, it just terminates them.

EBS volume AZ is a problem, regardless of this setting. I think yes you need an worker group per AZ then. And also ensure your cluster-autoscaler is configured correctly 🙂

[github-actions]

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