Setup VirtManager (KVM) in Debian based OSes.

virtmanager.sh

#!/bin/bash
set -e

# Install required packages
sudo apt update
sudo apt install -y qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils virt-manager

# Add current user to libvirt and kvm groups
sudo adduser "$USER" libvirt
sudo adduser "$USER" kvm

# Setup internet
if ! sudo virsh net-list --all | grep -q default; then
    sudo virsh net-define /usr/share/libvirt/networks/default.xml
fi

sudo virsh net-autostart default
sudo virsh net-start default || true

echo "Installation complete. Please log out and log back in for group changes to take effect."
echo "After that, you can run virt-manager with:"
echo "  virt-manager"