Kured: Safe Automatic Node Reboots for Kubernetes
Shriira Press
Keep your OS patched without keeping a pager. Kured turns the lonely, dangerous job of rebooting cluster nodes into a safe, automatic, coordinated routine.
Welcome to Kured: Safe Automatic Node Reboots for Kubernetes.
Kured — the KUbernetes REboot Daemon — is a CNCF sandbox project that solves one sharp, recurring operational problem: when the operating system on a cluster node needs a reboot to finish applying a patch, who reboots it, and how do you do that across a whole fleet without taking the cluster down with you? Kured answers by running a small DaemonSet on every node that watches for the reboot signal your package manager already leaves behind, then — only when it is safe — cordons and drains the node, takes a cluster-wide lock so no two nodes ever reboot at once, reboots, and uncordons again on the way back up. This free book teaches it from the ground up: the unpatched-node problem and what Kured is, the reboot sentinel it watches for, the lock that serializes reboots across the fleet, the cordon-drain-reboot-uncordon cycle, the guardrails that defer reboots during reboot windows or active Prometheus alerts, and how to run Kured well in production with notifications, metrics, and Helm. Six focused chapters with clear diagrams that make automated node maintenance concrete — so OS updates land themselves, one node at a time, while you sleep.
This title is part of the ShriIra library and is free to read in full, right here — our small contribution to making world-class knowledge easy to reach.
A note on reading it: open the Contents menu at the top of the reader to jump between chapters, use the Aa menu to set a comfortable text size, theme (light, sepia, or night), and single- or two-page layout. Your place is saved automatically, so you can always pick up where you left off.
We hope it serves you well.
— Shriira Press