Linux for containers

Flatcar Container Linux is an immutable Linux distribution for containers. It is a friendly fork of CoreOS Container Linux and as such, compatible with it.

Getting started

Flatcar Container Linux is a self-updating operating system designed for containers, making it ideal for running Kubernetes and other container platforms. Learn how to get started.

Get started!

Commercial support

Support for Flatcar Container Linux is offered by Kinvolk. Contact Kinvolk directly to find out more about commercial support and custom engineering services.

Contact Kinvolk

Getting help

You can interact with the Flatcar Container Linux community via IRC (Freenode #flatcar), the User mailing list or the Developer mailing list.

Join the conversation


What are the goals of the Flatcar Container Linux project?

The Flatcar Container Linux project delivers an independently built, distributed, and supported Linux distribution designed for container workloads.

We believe the approach that CoreOS pioneered with CoreOS Container Linux is correct and aim to preserve that.

We also believe the best open source projects are backed and supported by multiple commercial vendors that collaborate together in a mutually beneficial relationship. The benefits of this collaboration extend to users who receive a more stable and better maintained end product.

How does Flatcar Container Linux differ from CoreOS Container Linux?

It doesn't in any significant way. Flatcar Container Linux is a drop-in replacement for the EOL'd CoreOS Container Linux. Any minor changes you may need to consider are documented in the migration documentation.

Now that Red Hat has announced that CoreOS Container Linux is reaching end-of-life on May 26th, what are the plans for Flatcar Container Linux?

CoreOS Container Linux maintenance will be discontinued from May 26th, 2020, and publicly available binaries and images will be un-published September 1st, 2020 (see CoreOS announcement). Flatcar Container Linux understands itself as the successor in spirit and will continue following the philosophy pioneered by CoreOS, delivering a fully open source, minimal-footprint, secure by default and always up-to-date Linux distribution for running containers at scale.

We will continue to actively develop and support Flatcar Container Linux; updating key components such as the Linux kernel, systemd and Docker. We will also maintain support for Flatcar Container Linux as a drop-in replacement for CoreOS Container Linux for an extended migration period.

For users that require it, Kinvolk also offers commercial support subscriptions. Please reach out to for more information.

What is the Flatcar Container Linux LTS channel?

Flatcar Container Linux LTS releases will be maintained for an extended lifetime of 18 months. Throughout the maintenance period LTS releases will receive bug fixes and security updates. New LTS versions are released in a 12 month cadence, providing an overlap of 6 months to upgrade to a new LTS. The LTS channel is available to Kinvolk support subscription customers. You can read more about it in the Kinvolk customer support portal.

What do you mean when you say Flatcar Container Linux is “independently built”?

We mean that Flatcar Container Linux will continue to be updated and maintained after CoreOS Container Linux EOL, and is not dependent on any CoreOS Container Linux binary artifact.

What is the significance of the Flatcar Container Linux name?

A flatcar is the flat, open railcar used to transport containers.

Can I use Flatcar Container Linux today?

Yes! You can consult the documentation on how to use Flatcar Container Linux or go straight to the release page for links to each channel.

How can I get commercial support for Flatcar Container Linux?

Kinvolk offers commercial support and custom engineering services around Flatcar Container Linux (see this blog post for more details).

Contact Kinvolk for more information at

How is Flatcar Container Linux funded?

The main funding and engineering effort has been provided by Kinvolk.

Kinvolk is a Linux consulting company and intends to maintain and support the project going forward. Kinvolk sustains its effort by offering commercial support agreements for Flatcar Container Linux.

The Flatcar Container Linux open source project furthermore has a number of corporate sponsors. If your organization would like to become a sponsor, contact us at

Who is Kinvolk?

Kinvolk is a Berlin-based consulting company focused on building and supporting foundational open-source Linux technologies for cloud infrastructure.

Kinvolk is mostly known for its work on and around rkt, Kubernetes, systemd, BPF and the Linux kernel.