[systemd-devel] systemd-nspawn overlay and rootfs

[Lennart Poettering]

On Tue, 16.08.16 15:43, Juanjo Presa (juanjop at gmail.com) wrote:

> Hi, I'm trying to compose a container with several layers and join together
> with overlay option but seems that is not supported.
> 
> I want to get something like:
> systemd-nspawn --overlay=/foo/ubuntu-base:/foo/app-runtime:/foo/app:/ -D
> /foo/bar --boot
> 
> Maybe I'm misunderstanding the overlay option.
> 
> So, what do you suggest to accomplish a similar model. Maybe just mount the
> desired overlay sideways in /foo/bar and dismiss systemd-nspawn overlay
> option? Something similar with btrfs subvolumes?
> 
> Thanks in advance.

Yeah, we currently do not support overlayfs as root dir, see

https://github.com/systemd/systemd/issues/3847

We should probably make that work. But do note that overlayfs
introduces as many new problems as it solves IRL... Because of that
there's no first level support for it in place right now (i.e. no
support for using it as backing for --ephemeral or so).

Lennart

-- 
Lennart Poettering, Red Hat