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, containerd
• Flatcar Linux: Gentoo core, docker, containerd

Host Properties

Property	Flatcar Linux	Fedora CoreOS
Kernel	~5.10.x	~5.16.x
systemd	249	249
Username	core	core
Ignition system	Ignition v2.x spec	Ignition v3.x spec
storage driver	overlay2 (extfs)	overlay2 (xfs)
logging driver	json-file	journald
cgroup driver	systemd	systemd
cgroup version	v2	v2
Networking	systemd-networkd	NetworkManager
Resolver	systemd-resolved	systemd-resolved

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
Container Runtime	containerd 1.5.9	containerd 1.6.0
kubelet image	kubelet image with upstream binary	kubelet image with upstream binary
control plane images	upstream images	upstream images
on-host etcd	docker	podman
on-host kubelet	docker	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/cni/net.d
pod-manifest-path	/etc/kubernetes/manifests
volume-plugin-dir	/var/lib/kubelet/volumeplugins