Today I tried to add new worker nodes on one of my EKS cluster, running 1.18 k8s version. I wanted to see if I get any improvement with r6i.large instances, but they were not able to join the cluster…
VPC CNI version matters
I didn’t think about that, but the CNI version can actually prevent to add more recent instances on the cluster. The reason, apparently, is that the instance type compatible are actually hard-coded in a file, see this. Basically, if your instance type is not here, they will never be able to join the cluster correctly !
I have the 1.9.0 version of the CNI. I should update to 1.10.X, but I’ll wait after holidays !