Installing Linux alongside Mac + Windows AFTER Bootcamp

Question

I'm looking to set up triple-booting on my Macbook Pro, running OSX, Windows 7, and something Linux (probably Ubuntu 14.04)

Ordinarily, I don't think this would be too hard, but most of what I've found says all partitions (one for windows, one for linux, one for linux swap) should be created at the same time, before installing any of the additional OS's, or you can run into issues with unbootable windows and messed up partition tables.

The thing is, I have already gone through a full Bootcamp setup to get windows up and running, and have yet to create the linux partition(s).

The Mac disk utility is warning me that shrinking the Mac partition and creating new partitions AFTER setting up bootcamp Windows could make the Windows partition unbootable. Most of what I've found online seems to confirm that this is a valid issue, however almost all the discussions I've seen about this have been a few years old at least.

Have any of you set this up successfully on your systems? Can I get some pointers on what to do?

I'm thinking installing rEFInd to manage the partitions might be the key, but I don't have much experience with that sort of thing. Will rEFInd properly show the bootable disks? Will it replace the [hold option during startup] thing bootcamp made?

tl;dr - How do I nondestructively install Linux alongside existing OSX and Bootcamp Windows installs?

Also - I know VMs are a thing but I'd rather do an actual install.

Thanks!

System: Fall 2014 Macbook Pro 15" retina - 2.5 GHz i7, 16GB RAM, 500GB SSD, Nvidia GT 750 M and Intel graphics

Answer 1

I installed Ubuntu, Windows 7x32, Windows 7x64, and OS X 10.4 on a previous machine, and on my current one I am dual booting OS X 10.9 and Windows 8.1. I installed them using rEFIt (I never upgraded to rEFInd but it did work flawlessly-- and I cannot imagine rEFInd would work worse than its predecessor... If I reboot with extra drives attached -- USB ports, it finds those as well on boot.) I always tend to partition in advance with with either the Mac Disk Utility or gparted. You will have the best luck installing windows first-- less hassles.