We’re providing our own AMI node images for EKS using the self-managed node feature. The challenge I’m currently having is how to fetch the kubernetes version from within the EKS node as it starts up.

I’ve tried IMDS - which unfortunately doesn’t seem to have it:

root@ip-10-5-158-249:/# curl -H "X-aws-ec2-metadata-token: $TOKEN" http://169.254.169.254/latest/meta-data/
ami-id
ami-launch-index
ami-manifest-path
autoscaling/
block-device-mapping/
events/
hostname
iam/
identity-credentials/
instance-action
instance-id
instance-life-cycle
instance-type
local-hostname
local-ipv4
mac
metrics/
network/
placement/
profile
reservation-id

It also doesn’t seem to be passed in by the EKS bootstrap script - seems AWS is baking a single K8s version into each AMI. (install-worker.sh).

This is different from Azure’s behaviour of baking a bunch of Kubelets into a single VHD. I’m hoping for something like IMDS or a passed in user-data param which can be used at runtime to symlink kubelet to the correct kubelet version binary.

CodePudding user response：

Assumed you build your AMI base on the EKS optimized AMI; one of the possible way is use kubelet --version to capture the K8s version in your custom built; as you knew EKS AMI is coupled with the control plane version. If you are not using EKS AMI, you will need to make aws eks describe-cluster call to get cluster information in order to join the cluster; which the version is provided at cluster.version.