[shatteredgate]

You can just compare the APIs, namespaces are like the individual components of a jail. You can use them to build something like a jail, or something different that has a different security model. This was discussed a lot in an old HN thread: https://news.ycombinator.com/item?id=13982620

[trasz]

This doesn't really answer the question. Yes, the Linux API seems more flexible, but when you think about it, it really isn't, because all the models that actually make any sense can be implemented using simpler interface, which is what jails provide.

One real difference is that you need to be root to create a jail. It'll get fixed eventually - FreeBSD already has unprivileged chroot, jail isn't that much different.

[shatteredgate]

>Yes, the Linux API seems more flexible, but when you think about it, it really isn't, because all the models that actually make any sense can be implemented using simpler interface, which is what jails provide.

Not really, the example of Docker would probably be the most straightforward there. I don't think it's possible to fully port Docker to jails or at least I've never seen a successful port, some of the network topology features seem to just not be possible or straightforward. But I could be wrong, I have not looked into the technical details of this in years, somebody told me it might have been working a while ago but I never heard anything else about it since.

Needing to be root is a major deficiency though and I can't take jails seriously with that, one of the main focuses on Linux containers in the past several years has been to make unprivileged namespaces a good option.

[trasz]

Docker is literally just a jail. You can do whatever network topology you want using vnet.

And yes, having to use root is a major issue. Looks fixable though.

[shatteredgate]

Sorry, then I must be remembering some other issue. The effort to port docker to BSD seems to have disappeared.

>And yes, having to use root is a major issue. Looks fixable though.

AFAIK it took a long time to get this to work on Linux, there are a lot of security issues that it can cause.

[trasz]

Docker is practically dead, no wonder if disappeared :-)

Many things are hellishly complicated in Linux, due to politics and technical difficulties. Case in point: when I’ve started to work on NFSv4 ACLs, support in Linux was “worked on”, there was a prototype. It was 12 years ago. In FreeBSD, full supper for NFSv4 ACLs, from file systems to userspace tools, shipped decade ago. In Linux it’s still not there.

[shatteredgate]

Docker wasn't dead 5 or 6 years ago when I heard about this. In my experience some things are easier to implement in Linux and some are easier to implement in BSD. I don't particularly care for BSD's internal politics either, such as the licensing issues mentioned elsewhere here.

[nix23]

> It was 12 years ago. In FreeBSD, full supper for NFSv4 ACLs

You are right, but ironically we have to thank Microsoft for that ;)

[ori_b]

> Needing to be root is a major deficiency though

Note: Linux also needs root for its namespaces. Or at least CAP_SYS_SYSADMIN, which grants enough that it's pretty much as good as root. See setns(2) and clone(2) for details. This is one of the complaints the plan 9 people have always had with Linux namespaces.

[shatteredgate]

Not anymore, unprivileged user namespaces make it so you don't have to do that. That's how podman's "rootless containers" are able to work.

[ori_b]

Yes, I am aware that it's got more moving parts. What are you using this flexibility for?

[shatteredgate]

I'm using them for several things but the most straightforward one is probably that namespacing can be gradually added to services, you most likely see benefits from this already if you use systemd. That's one way that namespaces can be used in a different way from the docker model.

[ori_b]

What are you adding gradually, specifically? Like, a concrete example that names a namespace you may want to use. I'm trying to figure out what problems a half sandbox solves, and a vague "I just want to enable some capabilities" doesn't help here.

[shatteredgate]

A lot of the various security options in systemd: https://www.freedesktop.org/software/systemd/man/systemd.exe...

The sandboxing and mount-related ones are implemented with namespaces, and the idea with them is to not make any of them mandatory so they can be slowly added to system services. That way you can get some of the benefits without needing to build a full rootfs/container for the service. I am not sure how any of those would be done with jails because jails require you to create a chroot and network interface, whereas in Linux the mount and network namespaces are just optional namespaces and you can still use the other namespaces without using them.

[philkrylov]

> jails require you to create a chroot and network interface,

They don't: you may chroot to /, share the host's network interface, or disable networking.

[trasz]

It's literally a single command:

  trasz@v3:~ % doas jail / foo 127.0.0.1 /bin/sh
  # ps aux
  USER   PID %CPU %MEM   VSZ  RSS TT  STAT STARTED    TIME COMMAND
  root 37975  0,0  0,0 13500 3056  3  SJ   09:11   0:00,01 /bin/sh
  root 37976  0,0  0,0 13624 2776  3  R+J  09:11   0:00,00 ps aux

[kazen44]

also, with epairs you can do some really flexible networking stuff on freebsd between jails/jails and the host system and even jails and ipsec tunnels.

[shatteredgate]

Side note: I suppose you could chroot to /.