OS X templates for Packer and VeeWee

This is a set of Packer templates and support scripts that will prepare an OS X installer media that performs an unattended install for use with Packer and VeeWee. These were originally developed for VeeWee, but support for the VeeWee template has not been maintained since Packer's release and so it is only provided for historical purposes.

The machine defaults to being configured for use with Vagrant, and supports three providers:

• The Hashicorp VMware Fusion provider (recommended)
• Vagrant's included VirtualBox provider
• Parallels

It's possible to build a machine with different admin account settings, and without the vagrant ssh keys, for use with other systems such as CI.

Use with the Fusion provider requires Vagrant 1.3.0, and use with the VirtualBox provider Vagrant 1.6.3 if using the Rsync file sync mechanism. Note that the VeeWee template also does not have any VirtualBox or Parallels support.

Provisioning steps that are defined in the template via items in the scripts directory:

• Vagrant-specific configuration
• VM guest tools installation if on VMware
• Xcode CLI tools installation
• Chef installation via the Chef client installer for OS X
• Puppet installation via Puppetlabs Mac installers

Preparing the ISO

OS X's installer cannot be bootstrapped as easily as can Linux or Windows, and so exists the prepare_iso.sh script to perform modifications to it that will allow for an automated install and ultimately allow Packer and later, Vagrant, to have SSH access.

Run the prepare_iso.sh script with two arguments: the path to an Install OS X.app or the InstallESD.dmg contained within, and an output directory. Root privileges are required in order to write a new DMG with the correct file ownerships. For example, with a 10.8.4 Mountain Lion installer:

sudo prepare_iso/prepare_iso.sh "/Applications/Install OS X Mountain Lion.app" out

...should output progress information ending in something this:

-- MD5: dc93ded64396574897a5f41d6dd7066c
-- Done. Built image is located at out/OSX_InstallESD_10.8.4_12E55.dmg. Add this iso and its checksum to your template.

prepare_iso.sh also accepts three command line switches to modify the details of the admin user installed by the script.

• -u modifies the name of the admin account, defaulting to vagrant
• -p modifies the password of the same account, defaulting to vagrant
• -i sets the path of the account's avatar image, defaulting to prepare_iso/support/vagrant.jpg

For example:

sudo prepare_iso/prepare_iso.sh -u admin -p password -i /path/to/image.jpg "/Applications/Install OS X Mountain Lion.app" out

Clone this repository

The prepare_iso.sh script needs the support directory and its content. In other words, the easiest way to run the script is after cloning this repository.

Snow Leopard

The prepare_iso.sh script depends on pkgbuild utility. As pkgbuild is not installed on Snow Leopard (contrary to the later OS X), you need to install XCode 3.2.6 which includes it.

Use with Packer

The path and checksum can now be added to your Packer template or provided as user variables. The packer directory contains a template that can be used with the vmware-iso and virtualbox-iso builders. The veewee directory contains a definition, though as mentioned above it is not currently being maintained.

The Packer template adds some additional VM options required for OS X guests. Note that the paths given in the Packer template's iso_url builder key accepts file paths, both absolute and relative (to the current working directory).

Given the above output, we could run then run packer:

cd packer
packer build \
  -var iso_checksum=dc93ded64396574897a5f41d6dd7066c \
  -var iso_url=../out/OSX_InstallESD_10.8.4_12E55.dmg \
  template.json

You might also use the -only option to restrict to either the vmware-iso or virtualbox-iso builders.

If you modified the name or password of the admin account in the prepare_iso stage, you'll need to pass in the modified details as packer variables. You can also prevent the vagrant SSH keys from being installed for that user.

For example:

packer build \
  -var iso_checksum=dc93ded64396574897a5f41d6dd7066c \
  -var iso_url=../out/OSX_InstallESD_10.8.4_12E55.dmg \
  -var username=youruser \
  -var password=yourpassword \
  -var install_vagrant_keys=false \
  template.json

Automated installs on OS X

OS X's installer supports a kind of bootstrap install functionality similar to Linux and Windows, however it must be invoked using pre-existing files placed on the booted installation media. This approach is roughly equivalent to that used by Apple's System Image Utility for deploying automated OS X installations and image restoration.

The prepare_iso.sh script in this repo takes care of mounting and modifying a vanilla OS X installer downloaded from the Mac App Store. The resulting .dmg file and checksum can then be added to the Packer template. Because the preparation is done up front, no boot command sequences, attached devices or web server access is required.

More details as to the modifications to the installer media are provided in the comments of the script.

Supported guest OS versions

Currently this prepare script and template supports all versions of OS X that are distributed through the App Store: OS X Lion (10.7) through Yosemite (10.10), and currently the El Capitan Betas (10.11).

Automated GUI logins

For some kinds of automated tasks, it may be necessary to have an active GUI login session (for example, test suites requiring a GUI, or Jenkins SSH slaves requiring a window server for their tasks). The Packer templates support enabling this automatically by using the autologin user variable, which can be set to 1 or true, for example:

packer build -var autologin=true template.json

This was easily made possible thanks to Per Olofsson's CreateUserPkg utility, which was used to help create the box's vagrant user in the prepare_iso script, and which also supports generating the magic kcpassword file with a particular hash format to set up the auto-login.

System updates

Packer will instruct the system to download and install all available OS X updates, if you want to disable this default behaviour, use update_system variable:

packer build -var update_system=0 template.json

VirtualBox support

VirtualBox support is thanks entirely to contributions by Matt Behrens (@zigg) to this repo, Vagrant and Packer.

Caveats

Shared folders

Oracle's support for OS X in VirtualBox is very limited, including the lack of guest tools to provide a shared folder mechanism. If using the VirtualBox provider in Vagrant, you will need to configure the shared folder that's set up by default (current folder mapped to /vagrant) to use either the rsync or nfs synced folder mechanisms. You can do this like any other synced folder config in your Vagrantfile:

Vagrant.configure("2") do |config|
  config.vm.provider "virtualbox" do |vb|
    config.vm.synced_folder ".", "/vagrant", type: "rsync"
  end
end

Additional VM configuration for Packer

So far we've seen that the --cpuidset option needs to be passed to modifyvm as a line in the packer template if a Haswell Intel Mac is used to build the VM, at least as of VirtualBox 4.3.12. It seems to cause a VM crash on at least one older Mac, a Core 2 Duo-based 2010 Mac Mini, though did not cause issues on an Ivy Bridge 2013 iMac I tested. If it's missing on a Haswell Mac, however, the VM hangs indefinitely. This behaviour is likely to change over time as Oracle keeps up with support for OS X guests.

      "vboxmanage": [
        ["modifyvm", "{{.Name}}", "--cpuidset", "00000001", "000306a9", "00020800", "80000201", "178bfbff"],
      ]

Box sizes

A built box with CLI tools, Puppet and Chef is over 5GB in size. It might be advisable to remove (with care) some unwanted applications in an additional postinstall script. It should also be possible to modify the OS X installer package to install fewer components, but this is non-trivial. One can also supply a custom "choice changes XML" file to modify the installer choices in a supported way, but from my testing, this only allows removing several auxiliary packages that make up no more than 6-8% of the installed footprint (for example, multilingual voices and dictionary files).

Alternate approaches to VM provisioning

Mads Fog Albrechtslund documents an interesting method for converting unbooted .dmg images into VMDK files for use with ESXi.