InstallerChoices Discussion.markdown

Our Initial Question:

Q. What is the equivalent of a "Kickstart" (or preseed) file in OS X? What file can you create with OS X that would customize an OS X Install AT, or before, Install-time?

• My initial thought was the InstallerChoices.xml file - but as far as I'm aware that file isn't 'read' by the OS X Installer during Installation - it has to be submitted as an argument.

Greg responded to me with the below:

"Yes, I suppose the ChoiceChangesXML file (of whatever name) is the closest analogue of the Kickstart file.

You could create a workflow that curled an InstallerChoices.xml file and used it to install; there's no way to get Apple's Installer to do that for you that I know of. But if you are using disk-free NetBooting, you can do almost anything at that point."

There are articles here, and here on Netbooting from Linux machines. Ohad Levy is the author of a tool called The Foreman http://theforeman.org and is possibly looking at rolling this solution into The Foreman. What might be the best way to do this?

Feel free to comment below:

Sure, so we all know the experts at stripping down to a minimal, apple-flavored bootable OS kernel are the DeployStudio guys, and they might not be allowed to share. We could conceivably reverse-engineer what made it in to their 2.1GB bootable image and just have installer put those packages in a DMG a la instadmg, and just keep an eye on kexts/display drivers so future hardware is supported. Not the smallest of tasks, but I stripped a bunch of unnecessary packages out of iLife when I just needed iPhoto - and for that I didn't need a choiceChanges file, just a list of packages to install in a specific order.
Sorry I'm still hazy on the intent, where would this be put into use?

Read at the top .. "Ohad Levy is the author of a tool called The Foreman http://theforeman.org and is possibly looking at rolling this solution into The Foreman." http://twitter.com/#!/ohadlevy

Reversing DeployStudio is possible yes. Right now (some of) their code is in bash, actually :-) And we have this http://support.apple.com/kb/TA21133?viewlocale=en_US

not to get too far off track here, but DS uses a shell script called sys_builder.sh to… build a netboot system. the contents are also located here: /Applications/Utilities/DeployStudio Admin.app/Contents/Resources/DeployStudio Assistant.app/Contents/Resources/sysBuilder

so creating a bare boot image doesn't have to be a mystery. there's no mention of licensing in their file, but it would be worth checking on terms for the whole project or just contacting the developers.

with that said, i don't think there's anything on the mac side akin to a kickstart file. kickstart files are much more powerful. we don't even have machines that will netboot out of the box without human intervention (one of my long-standing gripes).

i'd expect apple licensing terms to get in the way with most of this.

the best bet is probably to get to a point where it's easy/trivial to reliably produce bare bootable images with configuration management tools in place to do the rest. i don't know that installerchoices or the like will need to be involved.

talked to ohadlevy on irc today, this gist is getting long now but ohwell :-)

beddari: ohadlevy: did you get any more comments om Mac-support?
ohadlevy: beddari: did you see the gist?
beddari: ohadlevy: yea me and glarizza kind of startet that
ohadlevy: beddari: honestly I didnt have much time to go over the way of how the image is created
beddari: ohadlevy: been thinking about it last few days as I'm in a situation where I'm dependent on DeployStudio and I don't quite like it
marcellods: ohadlevy: I do it now, but I think it's unhandy and I can't trigger. Foreman UI would be better.
ohadlevy: beddari: but for me there are a few high level questions
ohadlevy: 1. can we provide users a script to generate an image (and not to that touch image too often)
ohadlevy: 2. can we generate some sort of a template, which implement JeOS (just enough OS) to run puppet
ohadlevy: 3. can it be done automatically, or does it require some actions from the user (like boot from network vs boot from local disk)
beddari: 1,2,3 can all be done automatically
beddari: you would need to start with either the OS source DVD or a pristine computer as the source
beddari: I would prefer the DVD
beddari: and then you need to generate both a netboot image and what you call JeOS
ohadlevy: beddari: cant we do it over the network instead?
ohadlevy: or you are talking about image creation?
beddari: im talking about the creation yes
beddari: you could save both of those directly over the network using nfs of course
beddari: but you need to be able to use the os specific utils to generate the images
beddari: and as I say, you need two items, the netboot image (a reduced os image) and the JeOS image to be put on clients
beddari: you could - most likely, I havent tried yet - put Puppet on the netboot image
beddari: thats of course totally out of wack compared to kickstart-like workflows :-)
beddari: and thats for the image generation ..
ohadlevy: beddari: if we can provide a script to generate the image I think it would be fine
beddari: yes
ohadlevy: then we would probably need to change some files on the tftp server?
ohadlevy: and then the only question is how to feed in some sort of a post script
beddari: yea documented already at that edu link you had
ohadlevy: for example, maybe the image could do something like
ohadlevy: curl /script_for_mac | sh
ohadlevy: beddari: we do something similar in solaris
beddari: yea that is comparable technically
ohadlevy: beddari: my overall goal is:
ohadlevy: 1. user login in foreman, to define his host
ohadlevy: 2. network boot his mac
ohadlevy: 3. os is installed + puppet running
beddari: yes
ohadlevy: without any manual steps in between
beddari: right now, 2 is a bit awkward, as you'd need a special keypress to network boot
beddari: you could skip that but then you'd need to run a local utility on the client first to tell it to netboot next
ohadlevy: beddari: ok, thats an option too
ohadlevy: beddari: we do that with grub
beddari: yup but first time around you'd need the keypress or something else
beddari: :-)
ohadlevy: wont it default to network if it cant?
ohadlevy: or there is always an os installed?
beddari: no defaulting to network no, and os is always installed from apple
beddari: so manual intervention is needed in any of those two forms, an util that you run or a keypress at startup
ohadlevy: beddari: ok, I think we can live with that fore the moment, we are talking about users machines, so its not like servers that you need to go to a remtoe datacenter or something
beddari: this is something a lot of people complain about :-)
beddari: so, for me, the ideal way of solving this as open source would be if there existed a separate project for generating the netboot-image
beddari: right now noone does this as open source
beddari: deploystudio does it free but closed
beddari: the code however is available to read, its bash :-P
ohadlevy: :-)
beddari: they have the most detailed knowledge of this AFAIK
beddari: so I guess someone could just ask them for permission
beddari: a project like this could possibly live as python, as that is what most mac sysadmins use
ohadlevy: beddari: not ruby? ;-)
beddari: hmm nah for some reason python is mostly used among sysadmins
beddari: i guess it is to keep distance from the rails guys
beddari: if you get the netboot image done, then you could curl a script into that that did the imaging and post-installed puppet as the last step .. the installer-binary actually lets you set another device/path as root for the install
beddari: as long as the package is created correctly, which it is, for Puppets case :-)

Yep - those were the thoughts I had (minimal OS, prebaked image, holding 'N' for netboot, etc). I object to your Python comment wholeheartedly :)

When the OS X installer is running, early on there are messages in the logs like:

Opening OSInstall automation file '/Volumes/xxx/Mac OS X Install Data/minstallconfig.xml
/Volumes/xxx/Mac OS X Install Data/MacOSXInstaller.choiceChanges file found.
Applied choice changes from /Volumes/xxx/Mac OS X Installer.choiceChanges

So there's definitely a file or two that the installer reads to determine exactly what to install.

Python vs ruby : my brain can hold only so many scripting languages at one time. Python has pushed out Perl in my brain for the most part. I worry what Ruby might push out that I'll still need...

I would argue that Pyton did you a favor :) Let's see if we can't get Ruby to kill a couple of Fortran brain cells...