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Flatcar Linux takes the 520, drives up to Redmond: Microsoft acquires Kinvolk

It's safe with us, says Microsoft - but wasn't that what Red Hat said about CoreOS Container Linux?

Microsoft has acquired Kinvolk, a German open source company whose best known project is Flatcar Container Linux, a distribution designed for container workloads.

Kinvolk was founded in 2015 in Berlin and its first project was building a container runtime, called rkt, for Container Linux (formerly CoreOS), a lightweight Linux distribution. CoreOS Inc, the company behind Container Linux, was acquired by Red Hat in early 2018. Anxious for the future of Container Linux, Kinvolk founder and CEO Chris Kühl said "Flatcar Linux is a friendly fork of CoreOS's Container Linux and as such, compatible with it."

The rationale for Flatcar Linux was uncertainty about the future of Container Linux after Red Hat's acquisition. At the time, Red Hat product manager Rob Szumski said "Red Hat plans to continue Container Linux’s development" and promised that it would remain free.

Kühl was sceptical and said: "The strongest open source projects have multiple commercial vendors that collaborate together in a mutually beneficial relationship. This increases the bus factor for a project. Container Linux has a bus factor of 1. The introduction of Flatcar Linux brings that to 2."

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Last year Red Hat formally killed off CoreOS Container Linux, pointing users towards Fedora CoreOS but noting that it had no guarantees around stability, did not include rkt, and could not replace Container Linux "for all use cases."

'We and Microsoft are committed to doubling down on the Flatcar community'

Is Flatcar Linux now heading down the same road as Container Linux? Kühl said today that "this will not be a replay of the movie you’ve seen before. In fact, we and Microsoft are committed to doubling down on the Flatcar community: we want to expand the universe of partners, contributors, and users, to ensure a vibrant, successful and sustainable long-term future for Flatcar as a truly open, community-driven project."

Kühl said that his team will be working on "the full potential of eBPF in Kubernetes", where eBPF is extended Berkeley Packet Filter, a low level technology for running event-driven code in the Linux kernel, and bringing the Kinvolk open source capabilities to Azure Kubernetes Service and Azure Arc. He added that the open source projects will be remain active and for use "across all platforms."

Microsoft's Brendan Burns, corporate VP of Azure Compute and a co-founder of Kubernetes, said "we want to assure the Flatcar community that Microsoft and the Kinvolk team will continue to collaborate with the larger Flatcar community on the evolution of Flatcar Container Linux."

Kinvolk projects include not only Flatcar Linux but also Inspektor Gadget, a set of tools for inspecting and debugging Kubernetes, and Lokomotive, a Kubernetes distribution. Burns did not go into detail about how Microsoft plans to use these, saying only "stay tuned for more technical details soon."

Have we seen this movie before? It looks that way, but it is worth noting that Red Hat and Microsoft have different business models. Red Hat (which is owned by IBM) is in the business of licensing and supporting its Enterprise Linux products, which increasingly means OpenShift rather than merely RHEL (Red Hat Enterprise Linux).

Microsoft, on the other hand, operates public cloud infrastructure and profits (like AWS) when free software is run on Azure. Flatcar Linux joins a number of Kubernetes-related open source projects sponsored by the company, including Dapr (Distributed Application Runtime), KEDA (Kubernetes-based Event Driven Autoscaler) and Open Service Mesh. Whereas it was no real surprise when Container Linux transmuted into part of paid-for RedHat OpenShift, there is no such obvious path at Microsoft.

That said, the logic behind Kühl's 2018 post could apply equally to this new takeover. Perhaps we can expect a "friendly fork" of Flatcar Container Linux soon. ®

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