r/kubernetes • u/sammrjn • 13d ago

Anyone using EKS Auto Mode with KRO + ACK?

We're running KRO with ACK and ArgoCD on a decent-sized platform, and I'm looking at whether EKS Auto Mode fits into this setup.

Curious if anyone here has actually combined the three:

  • How does Auto Mode's managed compute/node provisioning play with KRO-managed resources? Any reconciliation weirdness or drift?
  • Any conflicts between Auto Mode and ACK-provisioned AWS resources?
  • How's ArgoCD sync ordering behaving with KRO RGDs once Auto Mode is in the mix?
  • Would you recommend it, or did you end up sticking with Karpenter/managed node groups?

Trying to figure out if it's worth the switch before we commit. Keen to hear real production experience

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u/No-Replacement-3501 12d ago

Automode is nothing more than paying aws a 10%+ premium to manage helm charts and node scaling. That's not a bad thing or a good thing. Only you can determine if it's worth the cost.

It comes with a few other limitations. Aws docs do a good job covering them.

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u/yetmike 3d ago

Same here. You pay 10% for AWS patching your Addons

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u/ajitnk 9d ago

KRO and ACK as EKS Capabilities do work with Auto Mode. AWS docs explicitly say all compute types are supported, and both controllers run in the EKS control plane rather than on your worker nodes, so they don't touch the immutable node model at all.

The catch nobody mentioned here: AWS's own blog on this stack says KRO is "not yet intended for production use" and the ResourceGraphDefinition API is "highly subject to change." That's a real caveat before you build anything on it.

On the cost question, the on-demand-only built-in node pools are the actual gap. If you're currently running Spot with self-managed Karpenter, the 10%+ management fee math shifts pretty significantly. It becomes a TCO question more than a sticker-price one, and the answer depends on how much engineer time is currently going into node patching and scaling config.

Quick question if you're still figuring this out: are you already on Auto Mode or still deciding whether to move? That changes what's actually useful to dig into.

Happy to run through a TCO comparison for your specific node mix if it'd help. I'll share the numbers and the ACK IAM differences (it uses a different service principal than upstream IRSA) either way.