Headless VirtualBox Part Two: Scripting the Setup

In January I posted about using the VirtualBox command line tool "VBoxManage" to make a new virtual machine on a headless system (https://opensecgeek.blogspot.com/2017/01/creating-remote-virtualbox-vm-with-ssh.html). Doing that for each one you want to make, though, gets tiring. It's a lot easier to script the process.

A few years ago I sat through a forensics class with a brilliant lad named Kevin. You can check him out at https://techanarchy.net. While our SANS instructor was telling a story about an experience he had with shadow copies, Kevin wrote a python script that searched a disk image for shadow copies and mounted each one into its own directory. By the end of the next break he'd added error checking and various other tidbits. That is not the depth of script I'm prepared to write.

Instead, I am content with a basic shell script that has some constants declared and then uses those to create a new VM.

Something Simple - Using What I Already Know

What I came up with was this:

In Plain Text

The text version (in case someone wants to cut/paste/edit) is:

#!/bin/sh

VBOX_CMD=/usr/bin/vboxmanage

VM_NAME=FBSDTemplate
VM_TYPE=FreeBSD_64 

MEM_SIZE=128 

HD_SIZE=10000
HD_FILE="VirtualBox VMs/$VM_NAME/$VM_NAME.vdi" 

RDP_PORT=3389

INST_FILE=FreeBSD-11.0-RELEASE-amd64-disc1.iso

echo Creating VM
$VBOX_CMD createvm --name $VM_NAME --ostype $VM_TYPE --register

echo Creating HD
$VBOX_CMD createhd --filename "$HD_FILE" --size $HD_SIZE

echo Adding IDE Controller
$VBOX_CMD storagectl $VM_NAME --name "IDE Controller" --add ide --controller PIIX4

echo Attaching HD
$VBOX_CMD storageattach $VM_NAME --storagectl "IDE Controller" --port 0 --device 0 --type hdd --medium "$HD_FILE"

echo Attaching DVD
$VBOX_CMD storageattach $VM_NAME --storagectl "IDE Controller" --port 0 --device 1 --type dvddrive --medium $INST_FILE

echo Setting RDP Port
$VBOX_CMD modifyvm $VM_NAME --vrdeport $RDP_PORT

echo Enabling RDP
$VBOX_CMD modifyvm $VM_NAME --vrde on

echo Setting Memory Size
$VBOX_CMD modifyvm $VM_NAME --memory $MEM_SIZE 

echo Powering on VM
$VBOX_CMD startvm $VM_NAME --type headless

Basically, I just took the steps from my previous post about headless VirtualBox and replaced the VM info with constants. Note that this script creates a VM with a 10GB hard drive and 128MB of RAM. That is fine for FreeBSD but if you create an Ubuntu Server VM you want at least 512MB of RAM or the installer may fail. Guess how I know...

Now if I want to roll out an Ubuntu VM I can just make sure I have the install ISO, edit a few constants at the top, run the script and the new VM is ready for installation and listening for a VRDE connection on port 3389.

You can get the above script with:

git clone https://github.com/kevinwilcox/vbox

Sample Output

When it runs, it looks a lot like this (notice I've changed the VM name from FBSDTemplate to OpenSecGeekScript):

Quick and easy!

In Closing

A more sophisticated script has its appeal - it would be nice to run a command and have it prompt for the VM name, a selection from a list of supported OS types, the amount of RAM, the hard disk size and even the ISO to use for installation. Perfect is the enemy of the good and, in this case, this is good enough for me. Well, it's good enough for a first run!