Fedora CoreOS – minimal container-focused Linux distribution

Fedora CoreOS is a minimal Fedora-based Linux distribution designed to run containerised workloads.

It is intended for clustered infrastructure but can also operate as a standalone system. The project brings together technology and ideas from CoreOS Container Linux and Fedora Atomic Host, with an emphasis on automated provisioning and low-touch operating-system maintenance.

Rather than treating the host as a conventional general-purpose server, Fedora CoreOS encourages applications and supporting services to run in containers. This helps keep the base operating system focused on providing a dependable platform for container workloads.

This is free and open source software.

Key Features

• Provisioning is handled by Ignition, allowing storage, files, users and systemd units to be defined declaratively before the system starts normal operation.
• Uses rpm-ostree for transactional operating-system updates, with deployments that support rollback if an update causes problems.
• Zincati can coordinate updates across groups of machines, helping administrators control how changes are rolled out through a cluster.
• Includes Podman and Docker-compatible tooling for running containers, with systemd integration available for managing containerised services.
• Keeps /etc and /var writable, while preserving /var across operating-system upgrades and rollbacks.
• Supports package layering through rpm-ostree when necessary, although project guidance recommends containers for additional applications and Toolbx for troubleshooting.
• Does not bundle a container orchestrator, leaving administrators free to deploy Kubernetes or other orchestration software as required.
• Can be deployed on bare metal, virtual machines and cloud infrastructure using images and installation methods appropriate to each environment.
• Makes use of Fedora security technologies including SELinux to provide a hardened foundation for container hosts.