Remote Virt-Manager

The goal is to run virt-manager from my Mac to manage VMs on a couple of remote KVM/QEMU host servers without needing to install an X11 environment on them. I’ve documented two options: the first uses a local virtual machine (VirtualBox/Parallels/…) with Ubuntu and a minimal GUI environment (just Xorg/X11 and virt-manager), the second uses HomeBrew.

Virtual Machine Option

I have Parallels as virtualization software, but this should work exactly the same with VirtualBox or any other virtualizer on your Mac.

VM Installation with Ubuntu

• I create a VM with Ubuntu Server 20.04 LTS: ubuntu-20.04.3-live-server-amd64.iso
• I install the Parallel Tools (optional)
• Shared networking — it will automatically assign an IP from the private range.

Network configuration from Parallels

• Parallels creates an entry in /etc/hosts with the virtual machine’s name and its IP. I verify it works and also disable the Ubuntu motd (Message of the Day).

luis@macos:~$ ssh -p 22 ubuntu-linux
: 
luis@ubuntu:~$ touch $HOME/.hushlogin

• I set up the minimal Xorg/X11 environment (more info):

luis@ubuntu:~$ sudo apt install xauth
:
luis@ubuntu:~$ sudo apt install virt-manager ssh-askpass-gnome --no-install-recommends

luis@ubuntu:~$ sudo apt install -y spice-client-gtk

• I set up SSH to connect from my ubuntu VM to a server called tierra running KVM/QEMU. Here’s a guide on SSH in Linux and another on SSH and X11 as root.

 virt-manager                   libvirtd
 host:ubuntu                    host:tierra
+-------------+               +--------------+
| luis@ubuntu | ---- ssh ---> | luis@tierra  |
+-------------+               +--------------+

• I configure the SSH client on ubuntu. In my case, the tierra server requires public key authentication.

luis@ubuntu $ ssh-keygen -t rsa -b 2048

• On the @tierra server, I add the user to the libvirt group.

root@tierra # cat /etc/group
:
libvirt:x:116:luis

• I verify…

luis@macos:$ ssh -Y -a luis@ubuntu-linux
:
luis@ubuntu:~$ ssh tierra
Enter passphrase for key '/home/luis/.ssh/id_rsa':

luis@tierra:~$
luis@tierra:~$ id
uid=1000(luis) gid=1000(luis) grupos=1000(luis),4(adm),24(cdrom),27(sudo),116(libvirtd)

Connecting from virt-manager in the virtual machine

luis@macos:$ ssh -Y -a -p 22 luis@ubuntu-linux
:
luis@ubuntu:~$ virt-manager

• File > Add Connection
  • Hypervisor: QEMU/KVM
  • (x) Connect to remote host via SSH
  • Username: luis
  • Hostname: tierra.yourdomain.com
  • Autoconnect: (X)
  • Generated URI: qemu+ssh://luis@tierra…

Remote SSH connection configuration

Virt-manager GUI

• Command-line connection

You also have the option to connect directly from the command line, or if your remote server listens on a different SSH port, replace XXXXX with the port number.

luis@ubuntu$ virt-manager -c 'qemu+ssh://luis@tierra.yourdomain.com/system?keyfile=id_rsa'

luis@ubuntu$ virt-manager -c 'qemu+ssh://luis@tierra.yourdomain.com:XXXXX/system?keyfile=id_rsa'

HomeBrew Option

• Virt-manager is not available in HomeBrew. There’s a custom formula that allows installing it, but it’s outdated and broken. Thanks to this Issues/184 and multiple forks, I found Damenly’s, which looks promising. Note that it’s super simple — it only installs virt-manager, not libvirt, and doesn’t support certain dependencies (such as the SSH password; read the README).
• I had some issues installing it and ended up uninstalling it. I’m leaving this here for tracking purposes.

brew tap Damenly/homebrew-virt-manager
brew install virt-manager --HEAD
brew install virt-viewer

• Once installed, we run:

export XDG_DATA_DIRS="/opt/homebrew/share/".
virt-manager -c test:///default