Repository navigation
Karpenter creates nodes with incorrect node names when using resource based naming #2892
Description
Version
Karpenter Version: v0.19.1
Kubernetes Version: v1.25.4
Expected Behavior
Karpenter should create node names containing only the instance ID (i-08dd5f2b3538142e9).
This is correct behaviour as documented in the AWS cloud provider documentation: https://cloud-provider-aws.sigs.k8s.io/prerequisites/
Actual Behavior
Karpenter creates node names containing only the instance ID + region domain (i-08dd5f2b3538142e9.eu-north-1.compute.internal)
Steps to Reproduce the Problem
Create a cluster using karpenter + resource based naming
Resource Specs and Logs
Not very relevant
Community Note
- Please vote on this issue by adding a ð reaction to the original issue to help the community and maintainers prioritize this request
- Please do not leave "+1" or "me too" comments, they generate extra noise for issue followers and do not help prioritize the request
- If you are interested in working on this issue or have submitted a pull request, please leave a comment
Activity
bwagner5 commentedon Nov 19, 2022
hmm I guess we patched this incorrectly.... although I'm a little confused on how this works.
Kubelet still uses the hostname as the node name, right? And when you turn on resource based naming on a subnet, the hostname of the instance would be with the domain
i-08dd5f2b3538142e9.eu-north-1.compute.internal. Is it expected that we use hostname-override in the kubelet to set the hostname as just the instance-id?olemarkus commentedon Nov 19, 2022
I think the confusion comes from legacy cloud provider vs external. Legacy uses the metadata service to get the hostname, which contains domain name, while external uses
os.Hostname(), which does not.We (cloud-provider-aws) decided to drop the domain part specifically to avoid
--hostname-override. The domain part also provides no value as part of the domain name.So make sure you are using the external cloud provider when using RBN.