Curious about non blackbox root process for Nexus devices

I have been a Linux based software developer for over 10 years but recently started looking into Android development and just purchased a Nexus 6 phone from Motorola to start hacking on. The first thing obviously is to unlock the bootloader (which seems really straight forward) and then root the phone. But this leads me to a question.

I have been searching the internet for root techniques for the Nexus device and I keep finding tutorials that point me to downloading premade files from others that root the phone in a blackbox fashion. I would rather understand the actual root process than just follow a cookie cutter process designed to make it easier for people who don't want to learn how to do it. So my question is this, does anybody know of any information anywhere that details and explains the rooting process without using others downloaded files or actually explains what those downloaded files are doing? I am a curious guy and don't really like blackboxes if I have an alternative. I would much rather learn the process so I can start figuring out how to hack on this phone more effectively.

Thanks for any information you can provide!

Adrian