Openshift Nginx permission problem [nginx: [emerg] mkdir() "/var/cache/nginx/client_temp" failed (13: Permission denied)]

I am currently running into a problem trying to set up nginx:alpine in Openshift.

My build runs just fine but I am not able to deploy with permission being denied with the following error

2019/01/25 06:30:54 [emerg] 1#1: mkdir() "/var/cache/nginx/client_temp" failed (13: Permission denied)

nginx: [emerg] mkdir() "/var/cache/nginx/client_temp" failed (13: Permission denied)

Now I know Openshift is a bit tricky when it comes to permissions as the container is running without root privilidges and the UID is gerenated on runetime which means it's not available in /etc/passwd. But the user is part of the group root. Now how this is supposed to be handled is being described here

https://docs.openshift.com/container-platform/3.3/creating_images/guidelines.html#openshift-container-platform-specific-guidelines

I even went further and made the whole /var completely accessible (777) for testing purposes but I still get the error. This is what my Dockerfile looks like

Dockerfile

FROM nginx:alpine

#Configure proxy settings
ENV HTTP_PROXY=http://my.proxy:port
ENV HTTPS_PROXY=http://my.proxy:port
ENV HTTP_PROXY_AUTH=basic:*:username:password

WORKDIR /app
COPY . .

# Install node.js
RUN apk update && \
    apk add nodejs npm python make curl g++


# Build Application
RUN npm install
RUN ./node_modules/@angular/cli/bin/ng build
COPY ./dist/my-app /usr/share/nginx/html

# Configure NGINX
COPY ./openshift/nginx/nginx.conf /etc/nginx/nginx.conf
COPY ./openshift/nginx/conf.d/default.conf /etc/nginx/conf.d/default.conf

RUN chgrp -R root /var/cache/nginx /var/run /var/log/nginx && \
    chmod -R 777 /var
RUN sed -i.bak 's/^user/#user/' /etc/nginx/nginx.conf

EXPOSE 8080

It's funny that this approach just seems to effekt the alpine version of nginx. nginx:latest (based on debian I think) has no issues and the way to set it up described here

https://torstenwalter.de/openshift/nginx/2017/08/04/nginx-on-openshift.html

works. (but i am having some other issues with that build so I switched to alpine)

Any ideas why this is still not working?

To resolve this. I think the Problem in this Dockerfile was that I used the COPY command to move my build and that did not exist. So here is my working

Dockerfile

FROM nginx:alpine

LABEL maintainer="ReliefMelone"

WORKDIR /app
COPY . .

# Install node.js
RUN apk update && \
    apk add nodejs npm python make curl g++


# Build Application
RUN npm install
RUN ./node_modules/@angular/cli/bin/ng build --configuration=${BUILD_CONFIG}
RUN cp -r ./dist/. /usr/share/nginx/html

# Configure NGINX
COPY ./openshift/nginx/nginx.conf /etc/nginx/nginx.conf
COPY ./openshift/nginx/conf.d/default.conf /etc/nginx/conf.d/default.conf

RUN chgrp -R root /var/cache/nginx /var/run /var/log/nginx && \
    chmod -R 770 /var/cache/nginx /var/run /var/log/nginx

EXPOSE 8080

CMD ["nginx", "-g", "daemon off;"]

Note that under the Build Application section I now do

RUN cp -r ./dist/. /usr/share/nginx/html

instead of

COPY ./dist/my-app /usr/share/nginx/html

The copy will not work as I previously ran the ng build inside of the container the dist will only exist in the container as well, so I need to execute the copy command inside of that container