Playbook Install And File/folder Permissions

I am having an issue chasing down the exact file/folder, owner permissions. Everything i can find only discusses the few files in the root folder and their "permission".

I have created a AWS instance running Ubuntu 16.04.

I ssh to the box (so I am the "ubuntu" user).

I follow the instructions on the Playbook install: How To: Configure the Environment for CS-Cart/Multi-Vendor right from the cs-cart help docs. This installation works perfectly, i can copy paste the commands in and run.

I then uploaded the multivendor_v4.9.1.zip and extract it in the directory defined when I edited the main.json file while following the instructions. For this discussion, assume the site is installed at

/var/www/html/example.com

I then open the website and finish the install, adding in the demo data. Everything works, site comes up, is accessible, etc.

Now is where the issue begins:

I attempt to use the Admin panel to Add an Add-on. I get the "The following directories do not have write permission: (essentially the app/addon and others).

I have also had he issue where various help/forums say to rename the /var/cache folder. Unfortunately this is also an issue as the cache files reside in the /var/cache/nginx folder.

So, looking at the /var/www/html/example.com folder, the owner group is root root and this goes for all the files and folders below.

php7 and nginx are running as root

ALL of the ownership settings were done by the Playbook install.

So, is there something wrong with the way the Playbook installs? What should the owner:group be set to in order to enable the Add On addition to actually work?

Thanks