Assets not loading in production for rails app
So I managed to fix this. In part to advice in this article http://nginxlibrary.com/403-forbidden-error/
for all the directories leading up to all the asset files, I set the directory permissions to chmod 775. And then for all the assets (application.js, etc...) inside apps/my_app/shared/assets I gave the files this permission chmod 775.
And that did the trick. In the article I linked to, the author mentions the need for the asset files to have both read and execute permissions, not just read.