Content not being copied over for nginx container

General
1

Github repo https://github.com/tenzan/nginx-docker

My Dockerfile:

FROM nginx
COPY sites-available-default /etc/nginx/sites-available/default
COPY app-dir /usr/share/nginx/html

where sites-available-default is the file and app-dir is a directory containing index.php

I was able to build and run container with steps:

docker build -t nginx-cont .
docker run --name nginx-cont -d -p 8080:80 nginx

and was able to check the nginx default page at http://192.168.99.100:8080/
where 192.168.99.100 is the docker-machine default ip.

Within from nginx-cont, I’ve confirmed that sites-available-default and the content of app-dir were not copied over. Where am I missing?

Thanks.