nginx and uwsgi in docker in vagrant in vmware - Permission denied on socket

[Larry Martell]

Don't ask why, but on my mac I am running Windows Server 2016 in
VMware. In there I am running Ubuntu in vagrant/Virtual Box. In there
I am trying to run a django app in a docker container with
nginx/uwsgi.

The socket is being created, but then when I try and connect to the
site it fails with this nginx error:

2017/08/19 16:56:29 [crit] 1251#1251: *1 connect() to
unix:///opt/django/CAPgraph/app.sock failed (13: Permission denied)
while connecting to upstream, client: 10.0.2.2, server: , request:
"GET / HTTP/1.1", upstream:
"uwsgi://unix:///opt/django/CAPgraph/app.sock:", host:
"localhost:9003"


I have verified that the app.sock file and all dirs along the path are
777. The /opt/django/CAPgraph dir is a docker volume mounted from a
local dir in the vagrant/Virtual Box VM

How can I debug this further?