Creating a Base Box

There are a special category of boxes known as "base boxes." These boxes contain the bare minimum required for Vagrant to function, are generally not made by repackaging an existing Vagrant environment (hence the "base" in the "base box").

For example, the Ubuntu boxes provided by the Vagrant project (such as "bionic64") are base boxes. They were created from a minimal Ubuntu install from an ISO, rather than repackaging an existing environment.

Base boxes are extremely useful for having a clean slate starting point from which to build future development environments. The Vagrant project hopes in the future to be able to provide base boxes for many more operating systems. Until then, this page documents how you can create your own base box.

Advanced topic! Creating a base box can be a time consuming and tedious process, and is not recommended for new Vagrant users. If you are just getting started with Vagrant, we recommend trying to find existing base boxes to use first.

What's in a Base Box?

A base box typically consists of only a bare minimum set of software for Vagrant to function. As an example, a Linux box may contain only the following:

Package manager
SSH
SSH user so Vagrant can connect
Perhaps Chef, Puppet, etc. but not strictly required.

In addition to this, each provider may require additional software. For example, if you are making a base box for VirtualBox, you will want to include the VirtualBox guest additions so that shared folders work properly. But if you are making an AWS base box, this is not required.

Creating a Base Box

Creating a base box is actually provider-specific. This means that depending on if you are using VirtualBox, VMware, AWS, etc. the process for creating a base box is different. Because of this, this one document cannot be a full guide to creating a base box.

This page will document some general guidelines for creating base boxes, however, and will link to provider-specific guides for creating base boxes.

Provider-specific guides for creating base boxes are linked below:

Packer and Vagrant Cloud

We strongly recommend using Packer to create reproducible builds for your base boxes, as well as automating the builds. Read more about automating Vagrant box creation with Packer in the Packer documentation.

Disk Space

When creating a base box, make sure the user will have enough disk space to do interesting things, without being annoying. For example, in VirtualBox, you should create a dynamically resizing drive with a large maximum size. This causes the actual footprint of the drive to be small initially, but to dynamically grow towards the max size as disk space is needed, providing the most flexibility for the end user.

If you are creating an AWS base box, do not force the AMI to allocate terabytes of EBS storage, for example, since the user can do that on their own. But you should default to mounting ephemeral drives, because they're free and provide a lot of disk space.

Memory

Like disk space, finding the right balance of the default amount of memory is important. For most providers, the user can modify the memory with the Vagrantfile, so do not use too much by default. It would be a poor user experience (and mildly shocking) if a vagrant up from a base box instantly required many gigabytes of RAM. Instead, choose a value such as 512MB, which is usually enough to play around and do interesting things with a Vagrant machine, but can easily be increased when needed.

Peripherals (Audio, USB, etc.)

Disable any non-necessary hardware in a base box such as audio and USB controllers. These are generally unnecessary for Vagrant usage and, again, can be easily added via the Vagrantfile in most cases.

Default User Settings

Just about every aspect of Vagrant can be modified. However, Vagrant does expect some defaults which will cause your base box to "just work" out of the box. You should create these as defaults if you intend to publicly distribute your box.

If you are creating a base box for private use, you should try not to follow these, as they open up your base box to security risks (known users, passwords, private keys, etc.).

"vagrant" User

By default, Vagrant expects a "vagrant" user to SSH into the machine as. This user should be setup with the insecure keypairs that Vagrant uses as a default to attempt to SSH. It should belong to a group named "vagrant". Also, even though Vagrant uses key-based authentication by default, it is a general convention to set the password for the "vagrant" user to "vagrant". This lets people login as that user manually if they need to.

To configure SSH access with the insecure keypair, place the public keys into the ~/.ssh/authorized_keys file for the "vagrant" user. Note that OpenSSH is very picky about file permissions. Therefore, make sure that ~/.ssh has 0700 permissions and the authorized keys file has 0600 permissions.

When Vagrant boots a box and detects the insecure keypair, it will automatically replace it with a randomly generated keypair for additional security while the box is running.

Root Password: "vagrant"

Vagrant does not actually use or expect any root password. However, having a generally well known root password makes it easier for the general public to modify the machine if needed.

Publicly available base boxes usually use a root password of "vagrant" to keep things easy.

Password-less Sudo

This is important!. Many aspects of Vagrant expect the default SSH user to have passwordless sudo configured. This lets Vagrant configure networks, mount synced folders, install software, and more.

To begin, some minimal installations of operating systems do not even include sudo by default. Verify that you install sudo in some way.

After installing sudo, configure it (usually using visudo) to allow passwordless sudo for the "vagrant" user. This can be done with the following line at the end of the configuration file:

vagrant ALL=(ALL) NOPASSWD: ALL

Additionally, Vagrant does not use a pty or tty by default when connected via SSH. You will need to make sure there is no line that has requiretty in it. Remove that if it exists. This allows sudo to work properly without a tty. Note that you can configure Vagrant to request a pty, which lets you keep this configuration. But Vagrant by default does not do this.

SSH Tweaks

In order to keep SSH speedy even when your machine or the Vagrant machine is not connected to the internet, set the UseDNS configuration to no in the SSH server configuration.

This avoids a reverse DNS lookup on the connecting SSH client which can take many seconds.

Windows Boxes

Supported Windows guest operating systems:

Windows 7
Windows 8
Windows Server 2008
Windows Server 2008 R2
Windows Server 2012
Windows Server 2012 R2

Windows Server 2003 and Windows XP are not supported, but if you are a die hard XP fan this may help you.

Base Windows Configuration

Turn off UAC
Disable complex passwords
Disable "Shutdown Tracker"
Disable "Server Manager" starting at login (for non-Core)

In addition to disabling UAC in the control panel, you also must disable UAC in the registry. This may vary from Windows version to Windows version, but Windows 8/8.1 use the command below. This will allow some things like automated Puppet installs to work within Vagrant Windows base boxes.

reg add HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /d 0 /t REG_DWORD /f /reg:64

Base WinRM Configuration

To enable and configure WinRM you will need to set the WinRM service to auto-start and allow unencrypted basic auth (obviously this is not secure). Run the following commands from a regular Windows command prompt:

winrm quickconfig -q
winrm set winrm/config/winrs @{MaxMemoryPerShellMB="512"}
winrm set winrm/config @{MaxTimeoutms="1800000"}
winrm set winrm/config/service @{AllowUnencrypted="true"}
winrm set winrm/config/service/auth @{Basic="true"}
sc config WinRM start= auto

Additional WinRM 1.1 Configuration

These additional configuration steps are specific to Windows Server 2008 (WinRM 1.1). For Windows Server 2008 R2, Windows 7 and later versions of Windows you can ignore this section.

Ensure the Windows PowerShell feature is installed
Change the WinRM port to 5985 or upgrade to WinRM 2.0

The following commands will change the WinRM 1.1 port to what's expected by Vagrant:

netsh firewall add portopening TCP 5985 "Port 5985"
winrm set winrm/config/listener?Address=*+Transport=HTTP @{Port="5985"}

Optional WinSSH Configuration

When using the WinSSH communicator, you may run into an issue where a PowerShell command can't display a progress bar. A typical error message might look like:

Win32 internal error "Access is denied" 0x5 occurred while reading the console output buffer.

In order to prevent this, we recommend setting $ProgressPreference = "SilentlyContinue" in your box's PowerShell profile:

if (!(Test-Path -Path $PROFILE)) {
  New-Item -ItemType File -Path $PROFILE -Force
}
 
Add-Content $PROFILE '$ProgressPreference = "SilentlyContinue"'

Other Software

At this point, you have all the common software you absolutely need for your base box to work with Vagrant. However, there is some additional software you can install if you wish.

While we plan on it in the future, Vagrant still does not install Chef or Puppet automatically when using those provisioners. Users can use a shell provisioner to do this, but if you want Chef/Puppet to just work out of the box, you will have to install them in the base box.

Installing this is outside the scope of this page, but should be fairly straightforward.

In addition to this, feel free to install and configure any other software you want available by default for this base box.

Packaging the Box

Packaging the box into a box file is provider-specific. Please refer to the provider-specific documentation for creating a base box. Some provider-specific guides are linked to towards the top of this page.

Distributing the Box

You can distribute the box file however you would like. However, if you want to support versioning, putting multiple providers at a single URL, pushing updates, analytics, and more, we recommend you add the box to HashiCorp's Vagrant Cloud.

You can upload both public and private boxes to this service.

Testing the Box

To test the box, pretend you are a new user of Vagrant and give it a shot:

$ vagrant box add --name my-box /path/to/the/new.box
...
$ vagrant init my-box
...
$ vagrant up
...

If you made a box for some other provider, be sure to specify the --provider option to vagrant up. If the up succeeded, then your box worked!