Focused, hands-on DevOps and server-side problems with hints, feedback, and automated solution checks.
A worker node dropped to NotReady and part of the workload went with it. The container runtime is fine and the control plane is healthy; the trail leads from kubectl symptoms down into systemd and the kubelet configuration. Diagnose the node and bring it back.
kubectl is dead: the kube-apiserver certificate expired and the control plane is down, while the workload quietly keeps serving. Diagnose the expiry offline, renew the certificates, bring the control plane back, and prove the cluster recovered.
Every kubectl command against a kubeadm cluster fails, and the workload is still serving. With no API to query, the usual tools tell you nothing. Work from the node itself to find what broke and bring the control plane back.
An app in the web namespace is served over HTTPS by an ingress-nginx Ingress. Create a Gateway and HTTPRoute on a staging hostname, verify traffic, move the production hostname to the Gateway, and remove the Ingress without downtime.
