run docker
docker run -d -p 80:80 docker/getting-started
docker expose port
docker run -p [external]:[Internal]
#example (will open in localhost:8080 to container port 80)
docker run -p 8080:80
dockerfile example
FROM ubuntu:18.04
COPY . /app
RUN make /app
CMD python /app/app.py
docker ARG
$ docker build --build-arg some_variable_name=a_value