Automating macOS using Ansible

I have a collection of macOS machines, some of which are used for services like Jenkins and others which are used for testing. These all have a consistent base configuration which I’ve been using Ansible to configure.

Ansible is being used to to drive a set of utilities that have emerged to help with some of the rougher edges of configuring macOS. In places where this abstraction isn’t available, I’m calling out to defaults write to set settings directly. There’s a few examples and a site dedicated to figuring out what’s possible.

I’m usually doing this in VMs, so I start by creating a new one using a set of Packer templates which create a base machine using a recent installer, runs updates and installs an ssh key. From here, I’ll then run an Ansible playbook that will:

  • Install Homebrew,
  • Set the dock position, size and contents,
  • Show devices on the desktop, align files to the grid, show hidden files, etc.

It ends up looking like this:

Ansible Configured macOS VM
Ansible Configured macOS VM

Some of these settings are the same on my own Macs, but most of these (like the dock and it’s contents) are all about making it as easy as possible to interact with it over a screen sharing session and having something consistent across the board.

To achieve these, I do this:

- name: Base OS X configuration
  hosts: all
    - geerlingguy.homebrew
    - base

This is the base playbook. It’s held in a central ansible repo, but here we’re installing Homebrew (using Jeff Geerling’s Homebrew Role) and then executing the base role. The base role looks like this:

- name: Install base utilities
    name: "{{ item }}"
    - m-cli
    - dockutil

- name: Remove all items from the Dock
  shell: /usr/local/bin/dockutil --remove all

- name: Set the default Dock items
  shell: "/usr/local/bin/dockutil --add {{ item }} --no-restart"
    - /Applications/
    - "\"/Applications/App\""
    - "\"/Applications/System\""
    - /Applications/Utilities/
    - /Applications/Utilities/
    - "/Applications --section others"
    - "~/Downloads --section others"

- name: Reduce the size of the Dock to 30 points
  shell: defaults write tilesize -int 30

- name: Show the Dock on the left-hand side
  shell: /usr/local/bin/m dock position LEFT

- name: Disable the Screensaver
  shell: defaults write idleTime 0

- name: Arrange Files by Kind
  shell: |
    /usr/libexec/PlistBuddy -c "Set :DesktopViewSettings:IconViewSettings:arrangeBy kind" ~/Library/Preferences/
    /usr/libexec/PlistBuddy -c "Set :StandardViewSettings:IconViewSettings:arrangeBy kind" ~/Library/Preferences/

- name: Set the Grid Spacing for Files
  shell: |
    /usr/libexec/PlistBuddy -c "Set :DesktopViewSettings:IconViewSettings:gridSpacing 54" ~/Library/Preferences/
    /usr/libexec/PlistBuddy -c "Set :StandardViewSettings:IconViewSettings:gridSpacing 30" ~/Library/Preferences/

- name: Use Smaller Icons
  shell: |
    /usr/libexec/PlistBuddy -c "Set :DesktopViewSettings:IconViewSettings:iconSize 48" ~/Library/Preferences/
    /usr/libexec/PlistBuddy -c "Set :StandardViewSettings:IconViewSettings:iconSize 64" ~/Library/Preferences/

- name: Show ~/Library
  shell: chflags nohidden ~/Library

- name: Show Drives on the Desktop
  shell: defaults write ShowHardDrivesOnDesktop -bool true

- name: Show External Drives on the Desktop
  shell: defaults write ShowExternalHardDrivesOnDesktop -bool true

- name: Show Removable Media on the Desktop
  shell: defaults write ShowRemovableMediaOnDesktop -bool true

- name: Show Hidden Files
  shell: defaults write AppleShowAllFiles -bool true

- name: Show File Extensions
  shell: defaults write NSGlobalDomain AppleShowAllExtensions -bool true

- name: Show the Status Bar in Finder
  shell: defaults write ShowStatusBar -bool true

- name: Show the Path Bar in Finder
  shell: defaults write ShowPathbar -bool true

- name: Restart Finder
  shell: killall Finder

It relies on m-cli and dockutil to reconfigure the dock and then relies on an Ansible form of some of my existing dotfiles script. These commands need to be run inside a shell, so they’re executed through shell (only through command will cause them to fail).

Of note, I found that I now need to set the ordering of Finder items and their size before showing additional devices. This wasn’t the case before OS X 10.11. (We need to use PlistBuddy because it’s nested, but this doesn’t seem to be the reason for why.)