Libguestfs - Oct 2016 - Re: virt-builder and Ubuntu 16.04 Xenial no access issue

Hello,

I created an Ubuntu 16.04 Xenial guest using virt-builder(1) with

   # virt-builder ubuntu-16.04
         -o /var/lib/libvirt/images/ubuntu-16.04.qcow2
         --size 10G --format qcow2
         --firstboot-command 'dpkg-reconfigure openssh-server'
         --arch x86_64

And imported it to libvirt with

   # virt-install --import --name ubuntu-xenial --ram 2048
         --disk path=/var/lib/libvirt/images/ubuntu-16.04.qcow2,format=qcow2
         --os-variant fedora23
         --graphics none

These successfully create the Ubuntu guest and import it as well. But

  - when I tried to access it using 'virsh console', it connects and
shows a
    blank screen. No interaction whatsoever.

  - When I tried to access it via ssh, it did not accept the root password that
    virt-builder had displayed before exiting.

  - I tried to reset root user password with virt-customize(1), but even that
    did not help.

In short, we have an Ubuntu guest that is not accessible anyhow.

I've reserved a beaker machine and have installed Ubuntu guest as above.

    $ ssh root@ibm-x3550m4-7.gsslab.rdu2.redhat.com + r3dhatd0tc0m

Please feel free to have a look at it. Thank you.
--
  - P J P
47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F

On Wed, Oct 19, 2016 at 12:45:19AM +0530, P J P wrote:
>   Hello,
> 
> I created an Ubuntu 16.04 Xenial guest using virt-builder(1) with
> 
>   # virt-builder ubuntu-16.04
>         -o /var/lib/libvirt/images/ubuntu-16.04.qcow2
>         --size 10G --format qcow2
>         --firstboot-command 'dpkg-reconfigure openssh-server'
>         --arch x86_64
> 
> And imported it to libvirt with
> 
>   # virt-install --import --name ubuntu-xenial --ram 2048
>         --disk path=/var/lib/libvirt/images/ubuntu-16.04.qcow2,format=qcow2
>         --os-variant fedora23
>         --graphics none
> 
> These successfully create the Ubuntu guest and import it as well. But
> 
>  - when I tried to access it using 'virsh console', it connects and
shows a
>    blank screen. No interaction whatsoever.
Yes, this is a bug.
>  - When I tried to access it via ssh, it did not accept the root password
that
>    virt-builder had displayed before exiting.
This might or might not be a bug, see below.
>  - I tried to reset root user password with virt-customize(1), but even
that
>    did not help.
This might or might not be a bug, see below.

[...]

I was able to reproduce this myself:

  $ virt-builder ubuntu-16.04 --firstboot-command "dpkg-reconfigure
openssh-server" --root-password password:123456

  $ qemu-system-x86_64 -nodefconfig -display none -machine accel=kvm:tcg -m 2048
-boot c -drive file=ubuntu-16.04.img,format=raw,if=ide -netdev
user,id=usernet,hostfwd=tcp:127.0.0.1:9000-:22 -device rtl8139,netdev=usernet
-serial stdio

Observe that it boots without any console output.

In another window, try:

  $ ssh -v root@localhost -p 9000

SSH will hang during connection.

If you repeat the same tests as above, but using fedora-24, it works fine.

By looking at the Ubuntu disk image directly, I was able to see that:

- it boots

- it runs the firstboot command, successfully

- the ssh server does not see any connections

- it is unclear if the root password is being set correctly or not,
  because we never actually test that

So this Ubuntu template is all-round buggy, and possibly or possibly
not there is another bug with setting passwords (only affecting
Ubuntu).

Noted, and I'll try to have a look at this soon.

Also we don't regression test any of this (for any guest), which is
another bug.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v

+-- On Tue, 18 Oct 2016, Richard W.M. Jones wrote --+
| I was able to reproduce this myself:
| 
|   $ virt-builder ubuntu-16.04 --firstboot-command "dpkg-reconfigure
openssh-server" --root-password password:123456
| 
|   $ qemu-system-x86_64 -nodefconfig -display none -machine accel=kvm:tcg -m 
|   2048 -boot c -drive file=ubuntu-16.04.img,format=raw,if=ide -netdev 
|   user,id=usernet,hostfwd=tcp:127.0.0.1:9000-:22 -device 
|   rtl8139,netdev=usernet -serial stdio
| 
| Observe that it boots without any console output.
| 
| In another window, try:
| 
|   $ ssh -v root@localhost -p 9000
| 
| SSH will hang during connection.
| 
| If you repeat the same tests as above, but using fedora-24, it works fine.
| 
| By looking at the Ubuntu disk image directly, I was able to see that:
| 
| - it boots
| 
| - it runs the firstboot command, successfully
| 
| - the ssh server does not see any connections
| 
| - it is unclear if the root password is being set correctly or not,
|   because we never actually test that
| 
| So this Ubuntu template is all-round buggy, and possibly or possibly
| not there is another bug with setting passwords (only affecting
| Ubuntu).

  I see. Thank you so much for these details.

To follow-up on it, today I created a 'debian-8' guest on the same
Beaker
machine. It too had the same issue of not booting with a 'console'
parameter.
But saving grace was, it at least shows the grub screen. So I was able to add 
the 'console=ttyS0,9600n8' kernel parameter and after that it worked
well with
the console.

Thank you so much!
--
 - P J P
47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F

See the workarounds for Debian 8 & Ubuntu 16.04 here:

https://www.redhat.com/archives/libguestfs/2016-October/msg00099.html

I tested password changing and that's working fine.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top