<p>I upgraded my EKS cluster to v1.11.5 from v.1.10.3, but it's giving me <code>x509: cannot validate certificate for &lt;WORKER_IP&gt; because it doesn't contain any IP SANs</code> error when i try to get logs or <code>helm ls</code> on it. Other commands like <code>kubectl get nodes</code> are working fine.</p>

<p>For the upgrade, I clicked "Upgrade cluster" button on the web console, and modified cloudformation template for workers to use latest AWS provided ami (ami-0a9006fb385703b54). read this <a href="https://docs.aws.amazon.com/eks/latest/userguide/update-cluster.html" rel="nofollow noreferrer">guide from AWS</a>, <a href="https://docs.aws.amazon.com/ko_kr/eks/latest/userguide/update-stack.html" rel="nofollow noreferrer">including this</a>.</p>

<p>My cluster was completely unuseable so I rollbacked my worker nodes with old ami (ami-0c7a4976cb6fafd3a) for now, and the error is gone. </p>

<p>I'm really not sure that what i missed. Anyone experiencing similar issue with me? I need help.</p>

<p>Thanks.</p>

Yechan Kim
<p>x509 is token authentication and authorisation way in kubernetes may be some that type of problem is there auth related. </p>
