REQUEST: Serial console via Archipel Client web gui

[tomzpl]

Dear Developers, I would like to propose a new feature that would allow serial consoles be accessed through VNC Console Tab.

I have some VMs that are not accessible through normal Display (VGA/XEN). It's possible to use virt-manager to switch between console and Graphical output via View -> Text Consoles. (http://www.tomz.pl/Aukcje/other/archipel6.png).

Regards,

[CyrilPeponnet]

I don't know how virt-manager is dealing with this. I don't find relevant information on libvirt side, if you can explain what is done behind the scene I could check if we could add it to the todo list :)

[tomzpl]

Its handled by libvirt: virsh console

You have some info here: https://fedoraproject.org/wiki/QA:Testcase_Virt_Serial_Console

and here:

http://libvirt.org/html/libvirt-libvirt.html virDomainOpenConsole - This opens the backend associated with a console, serial or parallel port device on a guest, if the backend is supported. If the @dev_name is omitted, then the first console or serial device is opened. The console is associated with the passed in @st stream, which should have been opened in non-blocking mode for bi-directional I/O.

Also patches used to open console remotely: http://www.redhat.com/archives/libvir-list/2010-August/msg00382.html

[Nowaker]

Really nice. I like it.

[tomzpl]

This is also used by LXC machines....

[CyrilPeponnet]

Yeah that's a great idea but virsh console needs to see a pseudo-terminal... I'm not sure it could be done in web interface. I'm digging on it, feel free to share if you know existing tools for remote console without ssh tunnel.

[Nowaker]

virt-manager can do it, and it's in Python.

EDIT: but yeah, there's ssh tunnel... So forget what I'm saying.

[tomzpl]

"To enable virsh console (or equivalent) to be used remotely it is neccessary to provide remote access to the /dev/pts/XXX psuedo-TTY associated with the console/serial/parallel device in the guest. The virStream API provide a bi-directional I/O stream capability that can be used for this purpose. This patch thus introduces a virDomainOpenConsole API that uses the stream APIs."

http://www.redhat.com/archives/libvir-list/2010-August/msg00382.html

And (this describes the problem was before with pseudo TTY access from remote)

https://bugzilla.redhat.com/show_bug.cgi?id=490191

or go via web-ssh:

https://bugzilla.redhat.com/show_bug.cgi?id=790789 + http://en.wikipedia.org/wiki/Web-based_SSH

Or run some system() or exec() but its not stateful.

[tomzpl]

Maybe this would be useful:

my $con = Sys::Virt->new('uri' => "qemu+tls://$url/system"); my $dom = $con->get_domain_by_name("name"); my $st=$con->new_stream(Sys::Virt::Stream::NONBLOCK); $dom->open_console($st, undef, 0);

http://stackoverflow.com/questions/18892447/perl-and-cpan-sysvirt-connect-to-vm-console

[CyrilPeponnet]

The issue is not this part, it’s more how I will show the console output to the web browser… Everything pass through XMPP Stanza (except noVNC)

And as the serial console could be really verbose, I assume it’s not a good idea to send / receive all message through xmpp.

We could get inspired from other projects like GateOne, at least for web console part, or we could use noVNC but we have to found a way to create a « console vnc server » on the hypervisor side.

Thanks for digging on it :) it helps !

[Nowaker]

noVNC acts as a websocket proxy. Maybe the same approach for a serial console websocket proxy?

[CyrilPeponnet]

That's what I said and maybe someone did it already.

I found the Server-side terminal emulation the best candidate for that.

[tomzpl]

Can we have an update on the progress? have you found any solutions that fits in?

[CyrilPeponnet]

No progress for now, no much time :) feel free to contribute if you want !