Flatcar Container Linux: The Immutable Container Host
Shriira Press
A minimal, immutable, auto-updating OS built to run containers. The CoreOS successor and an ideal Kubernetes node OS.
Welcome to Flatcar Container Linux: The Immutable Container Host.
Flatcar Container Linux is a minimal, immutable, container-optimized Linux distribution — a purpose-built host OS for running containers, and the community successor to CoreOS Container Linux. This free book teaches it from the ground up: the container-host problem and what Flatcar is, the container host and immutable infrastructure (plus the CoreOS heritage), Flatcar's minimal immutable design (the read-only filesystem), provisioning with Ignition (declarative first-boot config and Butane), automatic atomic updates (the dual-partition scheme, rollback, channels), running containers on Flatcar (the runtime, systemd, everything-is-a-container), Flatcar and Kubernetes (the ideal node OS, immutable nodes), update management at fleet scale (reboot coordination, FLUO/Kured, Nebraska), security (minimal attack surface, immutability, hardening), and operating Flatcar in practice across environments. Ten focused chapters with clear diagrams that demystify the immutable container-host model — a minimal, self-updating, secure OS for running containers reliably at scale.
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