Yosemite to ISO

yosemite-to-iso.sh

 #!/bin/bash

 # Mount the installer image
 hdiutil attach /Applications/Install\ OS\ X\ Yosemite.app/Contents/SharedSupport/InstallESD.dmg -noverify -nobrowse -mountpoint /Volumes/install_app

 # Convert the boot image to a sparse bundle
 hdiutil convert /Volumes/install_app/BaseSystem.dmg -format UDSP -o /tmp/Yosemite

 # Increase the sparse bundle capacity to accommodate the packages
 hdiutil resize -size 8g /tmp/Yosemite.sparseimage

 # Mount the sparse bundle for package addition
 hdiutil attach /tmp/Yosemite.sparseimage -noverify -nobrowse -mountpoint /Volumes/install_build

 # Remove Package link and replace with actual files
 rm /Volumes/install_build/System/Installation/Packages
 cp -rp /Volumes/install_app/Packages /Volumes/install_build/System/Installation/

 # Copy Base System
 cp -rp /Volumes/install_app/BaseSystem.dmg /Volumes/install_build/
 cp -rp /Volumes/install_app/BaseSystem.chunklist /Volumes/install_build/

 # Unmount the installer image
 hdiutil detach /Volumes/install_app

 # Unmount the sparse bundle
 hdiutil detach /Volumes/install_build

 # Resize the partition in the sparse bundle to remove any free space
 hdiutil resize -size `hdiutil resize -limits /tmp/Yosemite.sparseimage | tail -n 1 | awk '{ print $1 }'`b /tmp/Yosemite.sparseimage

 # Convert the sparse bundle to ISO/CD master
 hdiutil convert /tmp/Yosemite.sparseimage -format UDTO -o /tmp/Yosemite

 # Remove the sparse bundle
 rm /tmp/Yosemite.sparseimage

 # Rename the ISO and move it to the desktop
 mv /tmp/Yosemite.cdr ~/Desktop/Yosemite.iso