Creating a Base Box

As with every provider, the VirtualBox provider has a custom box format that affects how base boxes are made.

Prior to reading this, you should read the general guide to creating base boxes. Actually, it would probably be most useful to keep this open in a separate tab as you may be referencing it frequently while creating a base box. That page contains important information about common software to install on the box.

Additionally, it is helpful to understand the basics of the box file format.

Advanced topic! This is a reasonably advanced topic that a beginning user of Vagrant doesn't need to understand. If you're just getting started with Vagrant, skip this and use an available box. If you're an experienced user of Vagrant and want to create your own custom boxes, this is for you.

Virtual Machine

The virtual machine created in VirtualBox can use any configuration you'd like, but Vagrant has some hard requirements:

  • The first network interface (adapter 1) must be a NAT adapter. Vagrant uses this to connect the first time.

  • The MAC address of the first network interface (the NAT adapter) should be noted, since you'll need to put it in a Vagrantfile later as the value for config.vm.base_mac. To get this value, use the VirtualBox GUI.

Other than the above, you're free to customize the base virtual machine as you see fit.

Additional Software

In addition to the software that should be installed based on the general guide to creating base boxes, VirtualBox base boxes require some additional software.

VirtualBox Guest Additions

VirtualBox Guest Additions must be installed so that things such as shared folders can function. Installing guest additions also usually improves performance since the guest OS can make some optimizations by knowing it is running within VirtualBox.

Before installing the guest additions, you'll need the linux kernel headers and the basic developer tools. On Ubuntu, you can easily install these like so:

$ sudo apt-get install linux-headers-generic build-essential dkms

To install via the GUI:

Next, make sure that the guest additions image is available by using the GUI and clicking on "Devices" followed by "Install Guest Additions". Then mount the CD-ROM to some location. On Ubuntu, this usually looks like this:

$ sudo mount /dev/cdrom /media/cdrom

Finally, run the shell script that matches your system to install the guest additions. For example, for Linux on x86, it is the following:

$ sudo sh /media/cdrom/VBoxLinuxAdditions.run

If the command succeeds, then the guest additions are now installed!

To install via the command line:

You can find the appropriate guest additions version to match your VirtualBox version by selecting the appropriate version here. The examples below use 4.3.8, which was the latest VirtualBox version at the time of writing.

wget http://download.virtualbox.org/virtualbox/4.3.8/VBoxGuestAdditions_4.3.8.iso
sudo mkdir /media/VBoxGuestAdditions
sudo mount -o loop,ro VBoxGuestAdditions_4.3.8.iso /media/VBoxGuestAdditions
sudo sh /media/VBoxGuestAdditions/VBoxLinuxAdditions.run
rm VBoxGuestAdditions_4.3.8.iso
sudo umount /media/VBoxGuestAdditions
sudo rmdir /media/VBoxGuestAdditions

If you didn’t install a Desktop environment when you installed the operating system, as recommended to reduce size, the install of the VirtualBox additions should warn you about the lack of OpenGL or Window System Drivers, but you can safely ignore this.

If the commands succeed, then the guest additions are now installed!

Packaging the Box

Vagrant includes a simple way to package VirtualBox base boxes. Once you've installed all the software you want to install, you can run this command:

$ vagrant package --base my-virtual-machine

Where "my-virtual-machine" is replaced by the name of the virtual machine in VirtualBox to package as a base box.

It will take a few minutes, but after it is complete, a file "package.box" should be in your working directory which is the new base box. At this point, you've successfully created a base box!

Raw Contents

This section documents the actual raw contents of the box file. This isn't as useful when creating a base box but can be useful in debugging issues if necessary.

A VirtualBox base box is an archive of the resulting files of exporting a VirtualBox virtual machine. Here is an example of what is contained in such a box:

$ tree
.
|-- Vagrantfile
|-- box-disk1.vmdk
|-- box.ovf
|-- metadata.json

0 directories, 4 files

In addition to the files from exporting a VirtualBox VM, there is the "metadata.json" file used by Vagrant itself.

Also, there is a "Vagrantfile." This contains some configuration to properly set the MAC address of the NAT network device, since VirtualBox requires this to be correct in order to function properly. If you're not using vagrant package --base above, you'll have to set the config.vm.base_mac setting in this Vagrantfile to the MAC address of the NAT device without colons.

When bringing up a VirtualBox backed machine, Vagrant imports the first "ovf" file found in the box contents.