Spontaneous "Failed calling webhook error", occurs on cluster post-deployment, spontaneously

[kittywitch]

Internal error occurred: failed calling webhook “sigv4-aws-sigv4-proxy-admission-controller.k8s.aws”: failed to call webhook: Post “[https://sigv4-aws-sigv4-proxy-admission-controller-webhook-service.kube-system.svc:443/mutate?timeout=10s](https://sigv4-aws-sigv4-proxy-admission-controller-webhook-service.kube-system.svc/mutate?timeout=10s)”: no endpoints available for service “sigv4-aws-sigv4-proxy-admission-controller-webhook-service”

How to temporarily resolve if your cluster experiences this issue: aws/eks-charts#795 (comment)

Similar to aws/eks-charts#795 (comment)

The cluster spontaneously bricks itself (no pods come back into the cluster, due to being unable to) sometimes when this admission controller is used because when the webhook is unavailable it has no fallback.

It is something to do with the certificate generation and management system within the chart.

[insideClaw]

This bug was my greeting to trying out the chart. It bricked the cluster as described, with an attempt to even launch a simple unrelated pod throwing the error instead. Worked around by uninstalling the Helm chart and installing again.