add support for custom subnets in EKS (secondary cidr ranges)

[janwillies]

What problem are you facing?

The current EKS implementation does not allow to create pods in an additional subnet as per https://docs.aws.amazon.com/eks/latest/userguide/cni-custom-network.html

How could Crossplane help solve your problem?

I would like crossplane to create EKS clusters with custom network/secondary cidr ranges. Ideally I'd like to configure them like this:

apiVersion: compute.aws.crossplane.io/v1alpha3
kind: EKSClusterClass
metadata:
  name: custom-network
  labels:
    aws: "true"
    custom-network: "true"
specTemplate:
  # [...]
  subnetIds:
    - subnet-08a6e42f696140da4
    - subnet-074d2b84fc0fba006
  customSubnetIds:
    - subnet-026c046bb4fbd1468
    - subnet-065d50facdfe89127

[janwillies]

AWS announced future plans how to improve this feature: aws/containers-roadmap#398 (comment), especially:

• [EKS] [request]: Move VPC CNI configuration settings to ConfigMap aws/containers-roadmap#865 (configMap instead of aws-node daeamonset environment variables)
• [EKS] [request]: Simplify CNI custom networking aws/containers-roadmap#867 (removing max pods and custom ENIConfig CRs)

This should make the implementation a lot easier

[muvaf]

@janwillies does that mean if we pushed just a ConfigMap, that'd be all users need to do to get CNI?

[janwillies]

That is my understanding. However they also mention a tagging based option which will automatically discover secondary CIDR subnets for pods.

I guess we have to wait for the implementation, but it sounds really promising

[janwillies]

I believe this issue is old by now (there is a new eks api version available) and should be closed.