Trying to supply PGPASS to Docker Image

Question

New to Docker here. I'm trying to create a basic Dockerfile where I run a python script that runs some queries in postgres through psycopg2. I currently have a pgpass file setup in my environment variables so that I can run these tools without supplying a password in the code. I'm trying to replicate this in Docker. I have windows on my local.

FROM datascienceschool/rpython as base
RUN mkdir /test
WORKDIR /test
COPY requirements.txt requirements.txt
RUN pip install -r requirements.txt
COPY main_airflow.py /test
RUN cp C:\Users\user.name\AppData\Roaming\postgresql\pgpass.conf /test
ENV PGPASSFILE="test/pgpass.conf"
ENV PGUSER="user"
ENTRYPOINT ["python", "/test/main_airflow.py"]

This is what I've tried in my Dockerfile. I've tried to copy over my pgpassfile and set it as my environment variable. Apologies if I have a forward/backslashes wrong, or syntax. I'm very new to Docker, Linux, etc.

Any help or alternatives would be appreciated