Here you go:
https://pastebin.com/f5tL7xwx
There could probably be some additional refactoring here, but it works for my setup. I'm using default nginx paths, so they probably look different than other installs that use custom stuff like /var/www, etc.
Use it by putting it in a shell script, make it executable, then call it:
sudo scriptName.sh 28.0.1
Replace the version with whatever version you're upgrading to. I would highly recommend never upgrading to a .0, always wait for at least a .1 patch. I left some sleeps in the when I was debugging a while back, those are safe to remove assuming it works in your setup. I also noticed some variables weren't quoted, I'm not a bash programmer so there's probably some consistency issues that could be addressed if someone is OCD.