Running FreeBSD docker images on non-FreeBSD hosts

Jeff Terrell jeff at
Thu Jun 2 20:51:01 UTC 2016

On Wed, Jun 1, 2016 at 12:31 PM, Pete Wright <pete at> wrote:
>> So it looks like, if I'm committed to docker, I could run FreeBSD
>> inside a KVM inside a container on Linux. Then others who might be
>> interested in FreeBSD could play around with it on their Linux hosts
>> via docker.
> why?!?

Thanks for the challenge. (Seriously.) I don't want to add pain to
myself and others needlessly. :-)

> why put yourself and your co-workers through that much hell to test out
> freebsd.  having worked on docker (and before that other linux jail-like
> systems) i never understood the thought process that forces everyone to try
> to fit all use-cases under one umbrella like this.
> if you have some workflow that is totally docker depedent then just run
> freebsd+docker and be done with it.  you'll have some linux docker nodes,
> and some freebsd docker nodes and your on your way.
> or as mentioned earlier - there are all sorts of para-virtualization
> technologies that allow one to run freebsd ontop of a linux (or mac)
> hypervisor.  the benefit with either of these approaches is that you remove
> about 50 hoops and support headaches and probably learn a bit more about how
> to manage heterogeneous environments along the way.

I think these are great points. And if it were up to me, I can imagine
this would be a better approach in many respects.

But alas, this is for a project that I don't control. They've chosen
docker, and I'm trying to fit a FreeBSD option in among the mix as
painlessly as possible (for them). The fuller details are here, if
you're interested. [1]


(Indeed, I don't think this problem really requires virtualization at
all. It's just that nobody has solved my problem in a portable
language yet. The Java software [2], which I'm using indirectly from
the Clojure software [3], doesn't solve the problem directly but
instead uses JNA [4] to effectively shell out to a library,


That said, if one did create such a monstrosity as a docker image
containing a KVM hypervisor containing a FreeBSD VM—and figured out
how to pass commands and mount volumes from docker -> FreeBSD via
KVM—that could be a nice "evangelism" move to give the masses who use
docker a cheap and easy way to try out FreeBSD. Plus, such an image
could be used to provide FreeBSD support for other software as well.
Maybe I'll add that to my "one of these days" list...

Jeff Terrell, Ph.D. | Chief Technology Officer
(919) 357-3116 |

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