Skill map
Troubleshooting
Diagnoses packet, protocol, path, and service failures. As IT Support Specialist needs it.
Troubleshooting skill map
Careers that require it
- IT Support SpecialistImportance 5 of 5
- Network EngineerImportance 5 of 5
- Systems AdministratorImportance 5 of 5
Courses that teach it
HOWTOs
Concrete operational procedures from the courses on this page.
- How to upgrade a production Kubernetes cluster one minor version
Moving a self-managed kubeadm cluster forward one Kubernetes minor version, including the version-skew rules and pre-flight checks that decide whether the upgrade can proceed at all.
Kubernetes Operations
- How to drain and replace a worker node safely
Taking a worker node out of service for disruptive work or retirement without breaching any workload's availability guarantee, and returning it or removing it cleanly afterward.
Kubernetes Operations
- How to renew expiring kubeadm control-plane certificates
Renewing the one-year kubeadm control-plane certificates before they expire, and the offline recovery path for a cluster whose certificates have already lapsed and whose API server is down.
Kubernetes Operations
- How to rebuild a Kubernetes control plane from an etcd snapshot
The last-resort recovery when etcd data is lost or corrupt beyond quorum: replacing entire cluster state from a snapshot, with the data-loss and reconciliation consequences that come with it.
Kubernetes Operations
- How to migrate deprecated Kubernetes API usage before an upgrade
Clearing an upgrade blocker by locating every client, manifest, and controller still calling a Kubernetes API version the next minor removes, and proving the usage is gone before the upgrade.
Kubernetes Operations