Install and configure virtualbox on host (as root):
```
apt-get install -y virtualbox
useradd -m vbox -G vboxusers
passwd vbox # put the provided password in env file
echo 'VBOXWEB_USER=vbox' >> /etc/default/virtualbox
echo 'VBOXWEB_HOST=0.0.0.0' >> /etc/default/virtualbox
systemctl enable vboxweb-service
systemctl start vboxweb-service
```
Then reboot

Allow autostart VMs (as root):
```
echo 'VBOXAUTOSTART_DB=/etc/vbox' >> /etc/default/virtualbox
echo 'VBOXAUTOSTART_CONFIG=/etc/vbox/vbox.cfg' >> /etc/default/virtualbox
echo 'default_policy = allow' > /etc/vbox/vbox.cfg
chgrp vboxusers /etc/vbox
chmod 1775 /etc/vbox
# in vbox shell (su vbox, not sudo): VBoxManage setproperty autostartdbpath /etc/vbox
# for each VM, when not running, in vbox shell (su vbox, not sudo): VBoxManage modifyvm VM_NAME --autostart-enabled on

```