gke/ERR/2021_004
GKE nodes aren’t reporting connection issues to apiserver.
Product: Google Kubernetes Engine
Rule class: ERR - Something that is very likely to be wrong
Description
GKE nodes need to connect to the control plane to register and to report status regularly. If connection errors are found in the logs, possibly there is a connectivity issue, like a firewall rule blocking access.
Remediation
You can use the following filter to find matching log lines:
resource.type="k8s_node"
log_id("kubelet")
jsonPayload.MESSAGE:"Failed to connect to apiserver"