Note: To file an issue for any Flatcar repository, please use the central Flatcar issue tracker.
Welcome to the Flatcar community! Whether you're a user, contributor, or just curious — we're glad you're here! 👋
Flatcar Container Linux is a fully open source, minimal-footprint, secure by default and always up-to-date Linux distribution for running containers at scale.
Flatcar ships only the essentials needed to run containers — no package manager, no configuration drift. Its immutable, read-only filesystem minimizes attack surfaces, and atomic, automated updates keep your system secure and up-to-date without manual intervention.
Don't forget to check out flatcar.org for documentation, guides, and other useful resources!
- Flatcar Container Linux
Flatcar Container Linux has a dedicated documentation site. Start here:
- Getting Started — covers Ignition, local testing with QEMU, automatic updates, and cloud providers
| Resource | Link |
|---|---|
| Current Releases | flatcar.org/releases |
| Interoperability Matrix | interop-matrix.md |
| CIS Benchmarks | CIS reports |
We're a friendly bunch and always excited to chat! Here's where you can find us:
| Channel | Link |
|---|---|
| Discord (preferred) | discord.gg/PMYjFUsJyq — text, voice & video with contributors and maintainers |
| Matrix | #flatcar:matrix.org |
| Slack | #flatcar (Kubernetes Slack) |
| GitHub Discussions | flatcar/Flatcar/discussions |
| Mailing List (Users) | flatcar-linux-user |
💡 Want to report a bug or request a feature? File an issue. Have a question or not sure where to start? Jump into one of our chats and ask — we're happy to help!
| Platform | Link |
|---|---|
| Mastodon | @flatcar@hachyderm.io |
| Bluesky | @flatcar.org |
| X | @flatcar |
Come say hi! Check our Google Calendar (iCal) for all meeting times.
| When | 2nd Wednesday of every month at 2:30pm UTC (double check calendar) |
| Where | meet.flatcar.org/OfficeHours (all you need is a browser, no installations/accounts required) |
| Agenda | Office Hours Discussions |
Engage with the Flatcar community, learn about project directions, discuss contributions, and catch occasional demos of image-based Linux technologies. Each call includes a brief Release Planning update.
| When | 4th Wednesday of every month at 2:30pm UTC (check calendar) |
| Where | meet.flatcar.org/OfficeHours (all you need is a browser, no installations/accounts required) |
| Agenda | Developer Sync Discussions |
Backlog grooming, task planning, roadmap discussions, and day-to-day issues. If you want to get hands-on with development, this is the call for you!
🎥 All meetings are live-streamed on YouTube — recordings are linked in each meeting's agenda.
Found a bug or have a feature request? File an issue — please select the appropriate issue type to help us triage.
💡 Tip: Want a new package in the base image? Use the "New Package Request" issue type and check out the package addition guidelines.
Thinking of making a contribution? Engage with the project early — comment on an existing issue or create a new one. Making your intent visible is often the key to getting your work accepted!
For full details, check out our Contributing Guide which covers:
| Topic | What you'll find |
|---|---|
| Ways to Contribute | Code, docs, community, outreach, and more |
| Finding Issues | Labels like good first issue and help wanted |
| Development Setup | SDK walkthrough and developer guides |
| PR Lifecycle | From filing to merge |
| Commit Guidelines | Format, style, and best practices |
🌟 New to Flatcar? Consider building a Flatcar App — a great hands-on way to learn!
The Flatcar maintainer path is laid out in our governance document.
| Board | Description |
|---|---|
| Issue Tracker | Short-term concerns — bugs and minor enhancements |
| Tactical Board | What maintainers and contributors are currently working on |
| Release Board | Completed items assigned to upcoming releases |
| Releases Tracker | Track the status of each release across all channels |
| Roadmap Board | Epics, major features, and long-term items |
Flatcar Container Linux follows an Alpha → Beta → Stable release process:
- New features and major version upgrades enter Alpha, transition to Beta, then land in Stable.
- Bug fixes are released directly to the affected channel (Alpha fixes go to Alpha, Beta to Beta, Stable to Stable).
Within each channel, updates are planned on a 14-day cadence. Major releases follow a broader rhythm:
| Promotion | Target cadence |
|---|---|
| New major Alpha | Monthly |
| Alpha → Beta | Every 2 months |
| Beta → Stable | Every 3–4 months |
| New LTS | Yearly |
Up-to-date planning status is reflected in our release planning board. For the full release process documentation, see the Release Guide.
Some users prefer to avoid frequent version upgrades. The Flatcar LTS channel provides a longer support window:
| Detail | Value |
|---|---|
| Based on | A "golden Stable" release |
| Maintenance period | 18 months |
| New LTS frequency | Every 12 months |
| Upgrade window | 6 months overlap |
Flatcar is a community-driven project. Every participant — bug reporter, feature requester, code contributor — is considered a contributor. Maintainers have commit access and help govern the project, driving it forward and maintaining its scope and vision.
For full details see our governance document.
| Resource | Link |
|---|---|
| Governance | governance.md |
| Maintainers | MAINTAINERS.md |
| Security Policy | SECURITY.md |
We follow the CNCF Code of Conduct.
Please contact the private Maintainer mailing list or the Linux Foundation mediator, Mishi Choudhary (mishi@linux.com), to report an issue.
| Document | Description |
|---|---|
| CONTRIBUTING.md | How to contribute — finding issues, development setup, PR lifecycle, commit guidelines |
| RELEASES.md | Release channels, downloads, and the release process |
| governance.md | Project governance model, maintainer roles, and decision-making |
| MAINTAINERS.md | Current list of project maintainers |
| EMERITUS_MAINTAINERS.md | Former maintainers who have stepped down |
| ONBOARDING.md | Checklist for onboarding new maintainers |
| SECURITY.md | Security policy and vulnerability reporting |
| CODE_OF_CONDUCT.md | CNCF Code of Conduct |
| adding-new-packages.md | Guidelines for requesting and adding new packages to Flatcar |
| interop-matrix.md | Platform and provider interoperability matrix |
| CODEOWNERS | Code ownership and review assignments |
| LICENSE | Project license (Apache 2.0) |