Version option for update cluster command

[arun-gupta]

eksctl update cluster does not allow to specify a version to upgrade to:

eksctl update cluster --help
Update cluster

Usage: eksctl update cluster [flags]

General flags:
  -n, --name string          EKS cluster name
  -r, --region string        AWS region
  -f, --config-file string   load configuration from a file
      --approve              Apply the changes
  -w, --wait                 wait for all update operations to complete before exiting (default true)

How does eksctl know which version to upgrade to?

[errordeveloper]

@arun-gupta this was covered by initial discussion, but we didn't have an issue for it - thanks for opening it. The challenge her is that you can only go up by one version at a time, we will need to decide if we should automatically chain X number of upgrades, which will make the logic a little more complex.

[arun-gupta]

Agreed, that per skew policy, control plane can be upgraded only one minor version. But chaining X upgrades would be a simplified experience. Particularly, if #906 makes the update a holistic experience.

[scottyhq]

It would be great to also clarify how patch versions are dealt with (for example how to upgrade from 1.13.7 to 1.13.8). https://docs.aws.amazon.com/eks/latest/userguide/platform-versions.html

eksctl get cluster simply shows 1.13.

But Sometimes situations come up where it is desirable to apply patched versions to the cluster and nodegroups: aws/amazon-vpc-cni-k8s#282 (comment)

[aclevername]

Closed by #2318