Re: Help understand some guix concepts

[ludo@gnu.org (Ludovic Courtès)]

Hi,

Sorry for the late reply.

Amirouche Boubekki <amirouche.boubekki@gmail.com> skribis:

> *Q:* Does chroot guix/sd use chroot?

The build daemon, ‘guix-daemon’, uses chroot (among other tools) to
perform isolated builds:

  https://www.gnu.org/software/guix/manual/html_node/Invoking-guix_002ddaemon.html

> *Q:* Do guix developers use chroot somehow?

[...]

> *Q:* Do guix developers use 'guix system init' in combination with chroot?

They could, but it’s not very useful or convenient.  ‘guix system vm’ or
‘guix system container’ (the latter actually uses chroot(2)) are simpler
interfaces.

> *Q: *Does guix/sd use cgroups <https://en.wikipedia.org/wiki/Cgroups>?

No (not yet).

> *Q: *Does guix/sd containers enforce an image format?

No.

Docker & co. often associate “container” and “image format” because what
they deal with are binary images.

Conversely Guix and GuixSD have a detailed view of package composition,
service composition, etc.  Thus, they can spawn a container that
contains everything you specified (see ‘guix system container’ and ‘guix
environment -C’), and they can also create binary images that contain
everything you want (see ‘guix pack’ and ‘guix system vm-image’).

However, neither Guix nor GuixSD is in the business of running software
from containers in the format defined by Docker & co.

> *Q: *Can guix/sd use images? What are the advantages?
> *Q: *How does networking happens in guix/sd?
> *Q: *Is it possible to bind multiple interfaces via a bridge on the host
> system to the container?

Not easily so.

> *Q: *Is it possible or recommended to run shepherd inside a guix container?

‘guix system container’ runs GuixSD in a container, and GuixSD uses the
Shepherd.

> *Q:* isn't AppImage <https://en.wikipedia.org/wiki/AppImage> a
> "combination" of 'guix pack' and 'guix container'.

AppImage is a *format* for distributing software, as Wikipedia notes.

‘guix pack’ is a tool to create images (“binary images”, “bundles”,
depending on the preferred terminology).  See
<https://www.gnu.org/software/guix/blog/2017/creating-bundles-with-guix-pack/>.

> *Q: *Is it possible to have Xorg running inside a container and then use
> ssh -X to access it? Is there a way to avoid the ssh -X?

In theory we should be able to run Xorg in a ‘guix system container’,
but it would have to use a display different from that of the host.
Never tried though.

That said, you don’t need a running X server on the remote host to use
“ssh -X”.

HTH,
Ludo’.