FORGET WHAT I JUST SAID!
Forget about instaDMG! It was a helpful tool, but it was lacking in documentation, and it was getting a bit long in the tooth (for the past 3 or 4 OS X releases). Thankfully, MagerValp is a hero and wrote AutoDMG, which replaces instaDMG.
AutoDMG is written in python, and unlike instaDMG, it has a nice GUI to go with it. It supports the same features that instaDMG did, including OS updates and third-party installs, but perhaps the best things about it are completely new!
It has built in manifests for Apple Software updates, so you don’t have to spend your time finding URLs and checksums for them (in fact, you don’t have to worry about checksums at all).
It outputs images that are suitable for deployment with DeployStudio (or ASR, Absolute Manage, etc).
It has a host of other improvements as well, including drag and drop for adding the Install OSX.app (rather than having to extract the InstallESD.dmg manually), and most importantly – it is actively being developed by its users!
This is a rather short post because there isn’t a whole lot to explain about AutoDMG (which is part of its glory). It’s bundled as a .app so it is really easy to pick up and use.
- One note that is important to mention – all the solutions for creating never-booted images (instaDMG, AutoDMG, Filewave, etc) all suffer from the same limitation – you must build your images on the same major version of OS X. This is because the installer.app changes between OS X versions, so if you are making a 10.8 image on a 10.9 host, the functions the 10.8 package wants may not work. My workaround for this is usually a Virtual Machine if I don’t have spare hardware.