avengersassemble

FROM python:3
WORKDIR /app
COPY . .
RUN mkdir dummy && cd dummy && touch a.txt

avengersassemble

#(FROM python:3 is parent of WORKDIR /app i.e below instruction)
FROM python:3 
#(WORKDIR /app is child of FROM python:3 i.e. above instruction)
WORKDIR /app 
COPY . .
RUN pip install -r requirements.txt
RUN chmod +x /app/start.sh
ENTRYPOINT ["/bin/bash", "/app/start.sh"]

avengersassemble

services:
  web:
    build: .
    volumes:
      - sample_volume/:/app/dummy/
volumes:
  sample_volume:
    external: true