Bug 1222100

Looking around using "virtqemud" as keyword it seems like that's one of the modular daemons, where as I'm still using the monolithic daemon started by libvirtd.{service,socket}. Perhaps that's the reason?

Hmm the title of this issue might be wrong. Perhaps it should say virt-manager (4.1.0-17.1) instead. What I was using was virt-manager for opening the graphic console, I just thought it use virt-viewer underneath, but perhaps not so?

Switching to modular daemons[1] and using `virt-viewer -c ... $VM` directly I do not see the error message, however if I stick with virt-manager to connect to the graphical console, I would see the error "SSH tunnel error output: sh: line 1: nc: command not found".

1: https://libvirt.org/daemons.html#monolithic-vs-modular-daemons

Hi Jim, do you know whether it possible to use virt-*manager* to connect to remote libvirt server without having nc being installed?

(In reply to Shung-Hsi Yu from comment #3)
> Hi Jim, do you know whether it possible to use virt-*manager* to connect to
> remote libvirt server without having nc being installed?

Sorry for the delay. Yes, it's possible to connect virt-manager to *libvirt* without nc. The fact that you can see and manage (start, stop, etc) your VMs in virt-manager tells us it can connect to libvirt just fine using libvirt's virt-ssh-helper.

But virt-manager uses ssh tunneling + nc for VNC and spice

https://github.com/virt-manager/virt-manager/blob/main/virtManager/details/sshtunnels.py#L208

In this case, virt-manager is connecting to the VNC or spice server running in the qemu process, with something like

ssh -l root 
virt82.devlab.pgu1.suse.com sh -c 'nc -q 2>&1 | grep "requires an argument" >/dev/null; if [ $? -eq 0 ]; then CMD="nc -q 0 127.0.0.1 5900"; else CMD="nc 127.0.0.1 5900"; fi; eval "$CMD";'

Honestly, I'm not sure where to add the netcat-openbsd dependency. libvirt doesn't need it. And the qemu VNC or spice components don't need it either. virt-manager is the one explicitly using /usr/bin/nc, but it's a client app and cant guarantee the binary exists on the remote host.

We discussed this during one of our meetings and in the end decided libvirt is the best place to put the dependency. virt-manager will always need to connect to libvirt (using virt-ssh-helper) to get graphics configuration before launching virt-viewer, so placing the dependency in libvirt ensures /usr/bin/nc will there for virt-viewer's use.

(In reply to Shung-Hsi Yu from comment #0)
> See SR#1161600 for previous discussion.
> 
> 1: https://build.opensuse.org/request/show/1161600#status-history-31815024

Heh, in the end your initial fix is the one we settled on. I don't particularly like it, but does seem to be the least evil hack. Sorry for the run around in getting this fixed :-).

This is an autogenerated message for OBS integration:
This bug (1222100) was mentioned in
https://build.opensuse.org/request/show/1167494 Factory / libvirt

(In reply to James Fehlig from comment #6)
> (In reply to Shung-Hsi Yu from comment #0)
> > See SR#1161600 for previous discussion.
> > 
> > 1: https://build.opensuse.org/request/show/1161600#status-history-31815024
> 
> Heh, in the end your initial fix is the one we settled on. I don't
> particularly like it, but does seem to be the least evil hack. Sorry for the
> run around in getting this fixed :-).

No problem, I got a lucky guess heh :)

For completeness (in case anyone also come across this), there's a feature request for virt-manager at virt-manager/virt-manager#439 "RFE: use virt-ssh-helper instead of nc, if available"[1]. If that is implemented the requirement on nc should go away.

1: https://github.com/virt-manager/virt-manager/issues/439

(In reply to Shung-Hsi Yu from comment #9)
> For completeness (in case anyone also come across this), there's a feature
> request for virt-manager at virt-manager/virt-manager#439 "RFE: use
> virt-ssh-helper instead of nc, if available"[1]. If that is implemented the
> requirement on nc should go away.
> 
> 1: https://github.com/virt-manager/virt-manager/issues/439

Thanks for providing the link here. Currently virt-ssh-helper only supports relaying from ssh tunnel to the various virt daemon unix domain sockets. It will need enhanced to support relaying to network socket/ports before virt-manager can use it for tunneling VM graphical consoles.