typhoon/docs/architecture/operating-systems.md

Operating Systems

Typhoon supports Fedora CoreOS and Flatcar Linux. These operating systems were chosen because they offer:

• Minimalism and focus on clustered operation
• Automated and atomic operating system upgrades
• Declarative and immutable configuration
• Optimization for containerized applications

Together, they diversify Typhoon to support a range of container technologies.

• Fedora CoreOS: rpm-ostree, podman, moby
• Flatcar Linux: Gentoo core, rkt-fly, docker

Host Properties

Property	Flatcar Linux	Fedora CoreOS
Kernel	~5.4.x	~5.8.x
systemd	245	245
Ignition system	Ignition v2.x spec	Ignition v3.x spec
Container Engine	docker 19.3.12	docker 19.03.11
storage driver	overlay2 (extfs)	overlay2 (xfs)
logging driver	json-file	journald
cgroup driver	cgroupfs (except Flatcar edge)	systemd
Networking	systemd-networkd	NetworkManager
Username	core	core

Kubernetes Properties

Property	Flatcar Linux	Fedora CoreOS
single-master	all platforms	all platforms
multi-master	all platforms	all platforms
control plane	static pods	static pods
kubelet image	kubelet image with upstream binary	kubelet image with upstream binary
control plane images	upstream images	upstream images
on-host etcd	rkt-fly	podman
on-host kubelet	rkt-fly	podman
CNI plugins	calico, cilium, flannel	calico, cilium, flannel
coordinated drain & OS update	FLUO addon	fleetlock

Directory Locations

Typhoon conventional directories.

Kubelet setting	Host location
cni-conf-dir	/etc/kubernetes/cni/net.d
pod-manifest-path	/etc/kubernetes/manifests
volume-plugin-dir	/var/lib/kubelet/volumeplugins