Re: New VM image

[Ludovic Courtès]

Hello Chris,

Chris Marusich <address@hidden> skribis:

> Ludovic Courtès <address@hidden> writes:

[...]

>> I think it would fill the need of those who want to see what Guix is
>> like, and also the need of developers who want to test their software on
>> Guix without installing it (I’d argue that installing Guix on top of
>> their distro is simpler, but some people will use the VM image for that
>> purpose anyway.)
>>
>> What do people think?
>
> I like it!  Is it intended to replace gnu/system/examples/vm-image.tmpl?

Yes.  I’ve just committed it (538b99f31fb3eb41f90d6eb0e658e26e72123553)
before seeing your message, but I’m of course happy to take your
feedback into account.

> The phrase "live image" suggests a live USB stick that can be booted as
> a live system.  To avoid confusion, would it be better to just call it a
> "VM image"?  I don't feel that strongly about it.

Yes, definitely, sorry for the confusion.  I do not plan to change the
“VM” terminology in the manual and on the download page.

>> (define this-file
>>   (local-file "./vm-live.tmpl" "config.scm"))
>
> Cute!  But FYI, I tried building this and it failed at first, since I
> renamed the file and forgot about this reference.  I then re-ran the
> command from the same directory as the file, which of course worked.

Yeah, we could maybe extract the actual file name from
(current-source-location).

> When I booted into the system, I noticed some things:
>
> - There are many folders on the desktop.  For example, there is one for
>   "/sys/fs/cgroup/memory".  A minor blemish, but rather odd.

Yeah, that’s a longstanding issue with GLib/GIO: that library has code
to find out which mount points are “system” mount points (things that
should not be shown in the UI), but for some reason, it doesn’t work
correctly for us:

  https://lists.gnu.org/archive/html/help-guix/2017-11/msg00087.html

Any help to fix or work around the issue would be welcome!

> - The "guest" user cannot run "sudo".  However, after you invoke
>   "passwd" and change the password to something, you can invoke sudo.  I
>   guess this is a side effect of using an empty password.  Would it be
>   hard to arrange for the "guest" user to be allowed passwordless sudo?
>   I guess I should have listened to your comment in the config file and
>   given root/guest a password from the start!

What would it take to allow for password-less sudo?  We could do that.

> - "sudo herd status" reports that term-auto and user-homes is stopped,
>   which I think might be intended, but I'm not sure.  I also see
>   possibly unnecessary services: wpa-supplicant, upower-daemon.  The VM
>   probably doesn't need wpa-supplicant, but maybe it needs
>   upower-daemon?  Not sure.

True, the VM currently uses NM + wpa_supplicant, which we could
certainly replace with the DHCP client.

> - There is a "Web Browser" link at the bottom of the screen.  It begs to
>   be clicked.  But when you click it, the system asks you to choose a
>   default web browser, and there are no options.  Hmm.

Yeah, you first need to install one.

> - "sudo guix system reconfigure /etc/config.scm" failed because "error:
>   missing field initializers (home-directory)".

That error will vanish when we update ‘guix’ i guess.

>   I then ran "guix pull"
>   and tried again with "sudo -E guix system reconfigure
>   /etc/config.scm", since I remembered that the proper way to do this
>   using my freshly pulled Guix would be to use -E.  I got a new error:
>   "error: device '/dev/vda' not found: No such file or directory", which
>   occurred because the VM has /dev/sda but not /dev/vda.  Maybe we can
>   modify the config file to use sda instead?

It all depends on how you start QEMU: the device would be /dev/vda if
you use virtio, and /dev/hda otherwise.  In the manual, we should
probably give the incantation that leads it to use virtio:

  -device virtio-blk,drive=myhd -drive if=none,file=/tmp/t.img,id=myhd

The obvious downside is that it’s more verbose than just “-hda”.  The
upside is that it’ll perform better.

Thoughts?

Thanks,
Ludo’.