TLS handshake EOF in conversion webhook

[roehrich-hpe]

When a conversion webhook is enabled, we see the following errors appearing in the webhook log:

2024/08/02 20:44:32 http: TLS handshake error from 172.18.0.3:11133: EOF

That 172.18.0.3 is the IP of one of the control-plane nodes, and it's a message from the kube-apiserver to the webhook.

$ kubectl get nodes -o wide | grep 172.18.0.3
kind-control-plane   Ready    control-plane   85m   v1.29.4   172.18.0.3    <none>        Debian GNU/Linux 12 (bookworm)   6.6.32-linuxkit   containerd://1.7.15

This does not affect behavior of the webhook. There are numerous bugs in k8s land about this, and no one else is reporting an effect on behavior, either.

The concensus from various k8s and go bugs is that this is due to a timing issue in the go http library. This one contains a deep dive: kubernetes/kubernetes#109022, with a pointer to golang/go#50984 .