CoreOS Container Linux Alternatives
CoreOS Container Linux Alternatives
CoreOS Container Linux Alternatives
Yes, it’s true.
Six years since the first CoreOS release, our favorite container-optimized operating system has reached end-of-life.
So what are your options?
Clearly, if you are using CoreOS today, or are looking for a container-optimized Linux, you need to make a plan. But what are your options? Let's look at the alternatives and the facts you need to make that plan, depending on your use case and needs. Check out the leading CoreOS Container Linux alternatives below, or jump straight to our summary and conclusion.
So what options are available to you?
Fedora CoreOS
Fedora CoreOS is Red Hat’s official successor to CoreOS Container Linux. However, it is not a simple continuation of the original CoreOS: it is rather a merging of the former Red Hat Atomic Host with CoreOS Container Linux, with some key differences you should understand.
Flatcar Container Linux
Flatcar Container Linux is a “friendly fork” of CoreOS Container Linux, so is essentially identical. Maintained by Kinvolk, a company that worked closely with CoreOS in the early days, Flatcar is so close to CoreOS that in-place updates are practically seamless.
Red Hat Enterprise Linux CoreOS
Red Hat Enterprise Linux CoreOS (RHCOS) is Red Hat’s flagship container-optimized operating system. It is based on Fedora CoreOS, with each release subject to additional hardening/testing, and integration with OpenShift.
AWS Bottlerocket
Bottlerocket is a new offering in the container-optimized Linux space, from Amazon Web Services (AWS). It follows a lot of the CoreOS philosophy — minimal OS for container workloads with automatic atomic updates — but is primarily targeted at AWS's EC2 environment and EKS Kubernetes offering.
Summary
See how the leading CoreOS Container Linux alternatives stack up against each other, or scroll down to the conclusion if you just want to get to the bottom line.
Fedora CoreOS
Pros:
Cons:
Flatcar Container Linux
Pros:
Cons:
RHEL CoreOS
Pros:
Cons:
AWS Bottlerocket
Pros:
Cons:
Conclusion
And the winner is…
All of them!
There is no single "bottom line" because the path you choose depends on your needs and use case.
Instead, here are some recommendations based on some common scenarios.
Recommendations
If you are using Red Hat OpenShift
…then you should use RHEL CoreOS: it is bundled with your existing subscription, and fully integrated and supported.
If you want a seamless in-place upgrade for an existing CoreOS Container Linux deployment
…then Flatcar Container Linux is the only solution meeting your needs today.
If you want to try a cutting-edge operating system with the latest features, and are willing to live with occasional regressions or breaking changes and best-efforts community support (rather than a commercial support contract)
…then consider either Fedora CoreOS or Flatcar Container Linux. Both are good solutions.
If you want a container-optimized operating system with enterprise support AND you’re not using Red Hat OpenShift
…then you should use Flatcar Container Linux with a support subscription from Kinvolk. It is the only solution offering that capability today.
If you will only deploy on AWS, want an OS that is backed up by Amazon, and are willing to try something that’s not yet a stable, generally available release
… then Bottlerocket may be worth a look for you. However, Fedora CoreOS or Flatcar Container Linux will both give you essentially the same functionality, but with a more mature project and from platform-neutral project teams.