[aws-eks] Cluster Version Pinning

[pahud]

The Cluster resource in the eks construct library allows us to create Amaozn EKS cluster without specifying the version, however, when we create self-managed ASG nodegroup we need specify the version before we can construct correct ssm parameter store path for the AMI, which at this moment will honor the hardcoded LATEST_KUBERNETES_VERSION variable. However, if we version bump LATEST_KUBERNETES_VERSION, users with existing cluster and nodegroup will risk upgrading their self-managed nodegroup k8s version. For example 1.14 to 1.15 or even 1.14 to 1.16, while their cluster may remain 1.14.

However, for the Nodegroup resource, we don't have to specify the version as cloudformation will determine the version from the cluster, which ensures the version consistency.

I guess we might need to make the version property mandatory for Cluster and let users determine the version for their cluster as well as self-managed nodegroups if any.

Benefits

1. cluster version, managed nodegroup version and self-managed nodegroup version would be all consistent
2. version pinning would be possible
3. no forced version upgrade for self-managed NG
4. would be able to construct correct ssm parameter store path based on the user-provided version

Use Case

Proposed Solution

Other

• 👋 I may be able to implement this feature request
• ⚠️ This feature might incur a breaking change

---

This is a 🚀 Feature Request

[eladb]

Yes, this is exactly what I was thinking. We should get make version a required argument.

If we want a nice experience we can offer an extensible enum-like type, which is a common pattern we use:

export class KubernetesVersion {
  public static of(version: string) { return new KubernetesVersion(version); }

  public static V1_14 = KubernetesVersion.of("1.14");
  public static V1_15 = KubernetesVersion.of("1.15");

  private constructor(public readonly version: string) { }
}

Then, usage is:

new Cluster(this, 'MyCluster', {
  version: KubernetesVersion.V1_14,
  // or, if I want to use a version that is not defined in the "enum":
  version: KubernetesVersion.of("1.99")
}

[pahud]

@eladb Let me make it :-)

[abelmokadem]

Nice to see this one 👍

[pahud]

PR WIP. Will create a PR draft today.