For development purpose, I need to setup an installation of WP in a docker.

I found and follow this tutorial

Everything is working well, with all the security and optimisation. But the tutorial is based on WP 4.5.2. And when everything is setup I cannot upgrade WP because of some permission denied. Of course I modified by myself the Dockerfile to get WP4.7 but I will not be able to do the futur upgrade.

Also if I need to install a plugin, it fail because it cannot create the folder in my volume. If I mkdir -p the folders I everything is working fine.

Here the GitHub with all the files.

So I think everything is linked but I cannot fix it. Any idea ?