feat: eks convert command to convert EKS CustomResources between versions

[jonathan-innis]

kubectl used to have a supported a convert command that allowed you to perform conversion between two different API versions and know how to migrate between them. There are currently APIs that exist within EKS today that go through API graduation and have changes between the different graduation levels, similar to the graduation process that the core APIs went through.

A good example of this process is Karpenter which is going through its v1beta1 graduation process right now and is looking to add tool conversion support for migrating users between the alpha and beta versions of the API. Having this support in kubectl eks as kubectl eks convert would be an extremely nice feature to have.

The initial plan would be to support the Karpenter upgrade process and to expand out from that for other APIs in EKS that are not yet stable.

Examples of Usage

# Convert 'provisioner.yaml' to latest version and print to stdout.
kubectl eks convert -f provisioner.yaml

# Convert all files under current directory to latest version and create them all.
kubectl eks convert -f . | kubectl create -f -

[surajnarwade]

@jonathan-innis that sounds super cool.