I want to migrate an EKS cluster from a standard configuration to EKS Auto Mode using Terraform. Has anyone completed this upgrade what is process to take place before migration? If so, please share the steps and procedures for achieving this migration using Terraform.
First off, does AWS state that it is possible to migrate a running cluster? If it is not, then you would have to build a new one and migrate your workloads to it.
If they say it can be done, then build a test cluster using your current terraform and experiment. Not having done this myself, that is how I would go about it. Clearly you’re looking for plan to tell you the cluster state is changed, rather than recreated.
The provider documentation should also tell you whether modifying the attributes related to this would require recreation. If they do, then it’s plan B - new cluster and migrate workloads.
Other considerations are that auto-mode runs managed Karpenter, so you would probably need to disable whatever you use for cluster scaling before attempting an in-place change, assuming it is possible.