Hacker News Reader

Comment by e12e | Hacker News Reader

How is the Linux sub system/binary support for freeBSD these days? In theory this could be made to run Linux containers on the bsd kernel?

View on HN

You can find instructions how to create Ubuntu Jails inside FreeBSD.

There was an experimental Docker port for FreeBSD some years ago and it was actually working. I think it is mentioned here https://wiki.freebsd.org/Docker. However, it wasn't extremely useful as it didn't reach maturity, and because FreeBSD already had Jails. Which we were already using in production for the past ~15 years.

Linux containers make use of a kernel API which freebsd doesn't implement. However, you could run linux apps under a regular linux userspace inside of a freebsd jail.

Right, you couldn't run docker/dockerd, but you could run some docker images, probably? They're just filesystems with regular Linux binaries in them.

Ed: for example, AFAIK there's no native build of Microsoft sql server for freeBSD, but there's a release for Linux, and a docker (oci) image:

https://hub.docker.com/_/microsoft-mssql-server

So, assuming runj could fetch from docker hub, and interpret the images, you might in theory just:

runj run mcr.microsoft.com/mssql/server

(I'm not sure about the status of init vs oci - I know docker defaults to/uses tini these days?).

FreeBSD implements a nice Linux compatibility shim. It might be worth asking if the cost to implement the kernel API needed for this, is too high, or can be GSoC or something.

Reply on news.ycombinator.com