Best of 2018: Do FreeBSD and OpenBSD Need Docker Containers?

As we close out 2018, we at Container Journal wanted to highlight the five most popular articles of the year. Following is the first in our weeklong series of the Best of 2018.

Are OpenBSD and FreeBSD the next big frontier for Docker? Probably not. But efforts are underway to make containers run on OpenBSD and FreeBSD—which is kind of interesting if you’re into operating system diversity.

If you know much about Docker, you know it was born as a Linux-only technology. It originally depended on the LXC (short for Linux Containers) framework to work.

That’s no longer the case, and its official support has expanded somewhat. It can now run natively on certain versions of Windows, too.

However, by and large, it is still mostly a Linux-focused technology.

Jails and Chroot

If you know much about BSD-derived operating systems, such as OpenBSD and FreeBSD, you know that the *BSD world was years of ahead of Linux when it comes to container-like technology.

Jails, which make it possible to run applications inside isolated environments, were introduced with FreeBSD 4.0 in 2000. They predate Docker by 13 years.

For its part, OpenBSD has long supported the chroot command, which originated in Unix in 1979. (OpenBSD now supports jails, too.)

Jails and chroot are not quite the same thing as containers, but they essentially let you achieve the same results. In this sense, the *BSD community was doing containers when Docker founder Solomon Hykes was just entering his teens.

Containers for OpenBSD and FreeBSD

Yet not everyone in the *BSD world is content with jails and chroot. There have been calls for native Docker support for OpenBSD and FreeBSD, with users suggesting it might build on jails functionality to achieve such support.

Docker has yet to evince any interest in supporting OpenBSD or FreeBSD. However, at least two efforts exist on GitHub—here and here—to bring containers to these operating systems.

Unfortunately for *BSD-using fans, neither of those projects has been updated in years. It’s unclear whether the code even works, and it seems doubtful that it will be maintained.

Does *BSD Need Docker?

Some wonder whether the *BSD community has a need for Docker in the first place. If you can already use jails and virtual machines, what functionality does it give you?

The quick answer is that it would provide *BSD users access to a rich ecosystem. No matter how great you think jails are, they lack the massive commercial interest and vendor support that Docker containers have garnered since its release in 2013.

For Docker, too, it might be worth catering to the FreeBSD and OpenBSD crowds. The market share of these operating systems is small, but it’s persistent. And giving users another option beyond Linux and certain versions of Windows is not a bad thing. Users like choice.

Here’s hoping that third-party efforts to bring Docker to FreeBSD and OpenBSD don’t end up dead in the water.

Christopher Tozzi

Christopher Tozzi has covered technology and business news for nearly a decade, specializing in open source, containers, big data, networking and security. He is currently Senior Editor and DevOps Analyst with and

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